Clomipramine is an oral tricyclic antidepressant (TCA) similar in structure to imipramine and desipramine and was the first drug FDA-approved for the treatment of obsessive-compulsive disorder (OCD), and is used in adult and pediatric patients 10 years and older. Clomipramine is the most specific of all the TCAs with regard to its ability to inhibit serotonin reuptake versus norepinephrine reuptake, resulting in serotonergic activity. Anticholinergic and orthostatic effects may be more pronounced for clomipramine vs. other TCAs. Although clomipramine is used clinically to treat OCD, it is occasionally used off-label for major depression. Product labels for all antidepressants contain a boxed warning related to an increased risk of suicidality in children, adolescents, and young adults during the initial stages of therapy when treating depression or other conditions; therefore, the necessity of pharmacologic therapy versus the potential risks should be carefully considered in these populations.
General Administration Information
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Route-Specific Administration
Oral Administration
-During initiation and titration of dosage, administer with meals to reduce gastrointestinal adverse effects. Once a satisfactory daily dosage has been established the total dosage may be given at bedtime to minimize daytime sedation.
During clinical trials in adults and children with obsessive-compulsive disorder, the following psychiatric effects occurred more frequently in patients receiving clomipramine than placebo: nervousness (4% to 18%), memory impairment (7% to 9%), anxiety (2% to 9%), depression (5% or less), psychosomatic disorder (3% or less), confusion (2% to 3% ), agitation (3% or less), depersonalization (2%), irritability (2%), panic reaction (1% to 2%), and aggression (2% or less). During other clinical trial evaluations, abnormal thinking occurred in at least 1% of patients. Effects reported in 0.1% to 1% of treated patients included apathy, delirium, delusions, euphoria, hallucinations, hostility, mania, paranoia, phobic disorder, psychosis, suicidal ideation, and suicide attempt. Rarely reported effects (less than 0.1%) included catalepsy, illusions, impulse control symptoms, schizophrenic reaction, stupor, and completed suicide. Suicidal ideation has been reported in patients participating in clinical trials with antidepressants such as clomipramine. Therefore, clomipramine should be prescribed in the smallest quantity consistent with good patient management in order to reduce the risk of overdose. The symptoms of aggressiveness, akathisia (psychomotor restlessness), agitation, anxiety, sleep disturbance, irritability, hostility, mania, hypomania, impulsivity, and panic attacks have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality. Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients whose depression is persistently worse or who are experiencing emergent suicidality or symptoms that might be precursors to worsening depression or suicidal ideation. Changing or stopping the therapeutic regimen may be especially important if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms. Many of these adverse symptoms have been reported in clinical trials and have not always been associated with suicidality. Rapid discontinuation of many antidepressants may also result in some of these adverse CNS events. Because patients with a predisposition to hypomania or mania may experience such effects while on an antidepressant, patients should be adequately screened for bipolar disorder prior to initiating an antidepressant.
A wide variety of cardiovascular side effects can result from the use of tricyclic antidepressants due to their direct quinidine-like action, their potent anticholinergic properties, and their ability to potentiate norepinephrine. Ventricular tachycardia, palpitations, hypertension, and orthostatic hypotension all can be precipitated, with the possibility of more severe reactions occurring such as myocardial infarction, congestive heart failure, or stroke. Several tricyclic antidepressants can cause PR prolongation, QT prolongation, and can prolong the QRS interval, particularly with excessive dosage. Clomipramine is expected to produce similar ECG changes. Although all tricyclic antidepressants are thought to be proarrhythmic after acute overdoses, at therapeutic doses, their actions on the conducting system of the heart may vary. Imipramine has been utilized therapeutically for its antiarrhythmic effect. Patients most at risk for cardiovascular effects from this class of drugs have preexisting cardiovascular disease. ECG changes reported with clomipramine include premature ventricular contractions (PVCs), ST-T wave changes, and intraventricular conduction abnormalities. During clinical trials in adults and children with obsessive-compulsive disorder, the following adverse cardiovascular effects occurred more frequently in patients receiving clomipramine than placebo: orthostatic hypotension (4% to 6%), palpitations (4%), sinus tachycardia (2% to 4%), syncope (2% or less), and chest pain (unspecified) (4% to 7%). During other clinical trial evaluations, the following cardiovascular effects were reported in 0.1% to 1% of patients: abnormal ECG, arrhythmia, bradycardia, cardiac arrest, and extrasystoles. Rarely reported effects (less than 0.1%) included aneurysm, atrial flutter, bundle-branch block, heart failure, cerebral hemorrhage, AV block, myocardial infarction, myocardial ischemia, peripheral ischemia, thrombophlebitis, vasospasm, and ventricular tachycardia.
Drowsiness is the most frequent adverse CNS effect during therapy with tricyclic antidepressants. During clinical trials in adults and children with obsessive-compulsive disorder, the following centrally-mediated effects occurred more frequently in patients receiving clomipramine than placebo: drowsiness (46-54% vs 11-16%), dizziness (41-54% vs 14%), headache (28-52% vs 34-41%), insomnia (11-25% vs 7-15%), paresthesias (2-9% vs 2-3%), twitching (4-7% vs 1-5%), impaired concentration (<= 5% vs <=2%), hypertonia (2-4% vs <=1%), sleep disorder (4-9% vs <= 5%), yawning (<= 3% vs 0%), dysarthria (<= 3% vs 0%), abnormal dreaming (<= 3% vs <= 2%), migraine (<= 3% vs 0%), and paresis (<= 2% vs 0%). During other clinical trial evaluations, vertigo occurred in at least 1% of patients. CNS effects reported in 0.1-1% of patients included abnormal coordination, abnormal gait, ataxia, coma, dysphonia, encephalopathy, hyperkinesis, hypokinesia, muscle cramps, neuralgia, sensory disturbance, somnambulism, stimulation, and teeth grinding (bruxism). Rarely reported effects (< 0.1%) included aphasia, apraxia, generalized spasm, hemiparesis, hyperesthesia, hyperreflexia, hypoesthesia, indecisiveness, mutism, neuropathy, nystagmus, and oculomotor nerve paralysis. In clinical trials with clomipramine, sedation was the most common reason why patients discontinued therapy. Sedation can be made into a desirable effect by administration of the tricyclic antidepressant at bedtime, which minimizes undesirable drowsiness during the day. Patients should be cautioned about driving, operating machinery, or engaging in other tasks requiring mental alertness until they know how clomipramine affects them. Dizziness is usually due to orthostatic hypotension and can be reduced by having the patient change positions more slowly.
During clinical trial evaluation of clomipramine for obsessive-compulsive disorder (OCD), appetite stimulation was reported in 11% of adults and 0% of children receiving clomipramine and 2% of adults and children receiving placebo. Weight gain occurred more frequently in clomipramine-treated patients (adults: 18%; pediatrics: 2%) than placebo-treated patients (<= 1%). Of the adult patients with weight gain, 28% gained at least 7% of their initial body weight compared to 4% of those on placebo. Weight gain in excess of 25% of initial body weight occurred in some instances. Weight loss of at least 7% of initial body weight occurred in 5% of patients in the active treatment group compared to 1% in the placebo group. Weight gain has been noted with the use of most tricyclic antidepressants; the mechanism may involve changes in the CNS control of appetite, including alterations in leptin and other factors. Because weight gain is influenced by many factors, including emotional factors and metabolic factors, the extent and time course of this side effect are hard to predict for any given patient.
Peripheral nervous system adverse reactions can occur during therapy with tricyclic antidepressants like clomipramine. Tremor can result from norepinephrine reuptake blockade. Rarely, extrapyramidal symptoms can occur in both young and elderly patients. Pseudoparkinsonism is more likely to occur in the elderly, especially if they are receiving high doses. During clinical trial evaluation of clomipramine for obsessive-compulsive disorder (OCD), tremor was reported in 54% of adults and 33% of children receiving clomipramine compared to 2% of adults and children receiving placebo. During other clinical trial evaluations of clomipramine, dyskinesia was reported in 0.1-1% of patients. Rarely reported effects (< 0.1%) included dystonic reaction (i.e., torticollis, oculogyric crisis) and choreoathetosis.
During pre-marketing evaluation of clomipramine, the incidence of seizures increased with cumulative exposure to the drug at doses up to 300 mg/day, ranging from 0.64% at 90 days to 1.45% at 365 days of treatment. One short-term study in patients with obsessive-compulsive disorder found a higher incidence of seizures at doses greater than 300 mg/day (2.1%) than with doses less than 250 mg/day (0.48%). Seizures and EEG changes have been observed more commonly in children than in adults during therapy with tricyclic antidepressants including those using clomipramine. Myoclonia occurred in 13% of adults and 2% of children receiving clomipramine during clinical trial evaluation for obsessive-compulsive disorder compared to 0% of adults or children receiving placebo. Patients who have a preexisting seizure disorder may require increased concentrations of their anticonvulsant to maintain seizure control.
During clinical trials in adults and children with obsessive-compulsive disorder, the following adverse effects related to special senses occurred more frequently in patients receiving clomipramine than placebo: visual impairment (7-18% vs 2-4%), dysgeusia (4-8% vs 0%), tinnitus (4-6% vs 0%), abnormal lacrimation (<= 3% vs <= 2%), mydriasis (<= 2% vs 0%), conjunctivitis (<= 1% vs 0%), anisocoria (<= 2% vs 0%), blepharospasm (<= 2% vs 0%), and ocular allergy (<= 2% vs 0%). During other clinical trial evaluations, the following effects were reported in 0.1-1% of patients: abnormal accomodation, hearing loss, diplopia, otalgia, ocular pain, foreign body sensation, hyperacusis, parosmia, photophobia, scleritis, and taste loss. Rarely reported effects (< 0.1%) included blepharitis, chromatopsia, conjunctival hemorrhage, exophthalmos, glaucoma, keratitis, labyrinth disorder, night blindness, retinal disorder, strabismus, and visual field defect. Ocular manifestations of the anticholinergic actions of the tricyclic antidepressants such as clomipramine include blurred vision due to cycloplegia, mydriasis, and increased intraocular pressure. Angle-closure glaucoma has been reported during post-marketing use. Ocular hypertension can precipitate a crisis in patients with angle-closure glaucoma. Ophthalmological examination is recommended when there are visual changes.
During clinical trials in adults and children with obsessive-compulsive disorder, the following adverse gastrointestinal (GI) effects occurred more frequently in patients receiving clomipramine than placebo: xerostomia (63% to 84%), constipation (22% to 47%), nausea (9% to 33%), dyspepsia (13% to 22%), diarrhea (7% to 13%), anorexia (12% to 22%), abdominal pain (11% to 13%), vomiting (7%), flatulence (6% or less), tooth disorder (5% or less), dysphagia (2% or less), esophagitis (1% or less), ulcerative stomatitis (2% or less), and halitosis (2% or less). During other clinical trial evaluations, the following GI effects were reported in 0.1% to 1% of patients: blood in stool, colitis, duodenitis, peptic ulcer, gastritis, gastroesophageal reflux, gingivitis, glossitis, hemorrhoids, hypersalivation, irritable bowel syndrome, rectal hemorrhage, tongue ulcer or oral ulceration, and dental caries. Rarely reported effects (less than 0.1%) included cheilitis, chronic enteritis, stool discoloration, gastric dilatation, gingival bleeding, hiccups, GI obstruction, oral/pharyngeal swelling, paralytic ileus, and enlarged salivary gland. GI manifestations associated with anticholinergic activity of tricyclic antidepressants include thirst, xerostomia, constipation and adynamic ileus. Constipation is more commonly observed in elderly patients. If these symptoms become severe, discontinuation of the drug may be necessary. In clinical trials with clomipramine, nausea/vomiting was the second most common reason patients discontinued therapy, second only to drowsiness.
During clinical trials in adults and children with obsessive-compulsive disorder, the following dermatologic effects were reported in patients receiving clomipramine at incidence rates higher than placebo: hyperhidrosis (9% to 29%), rash (unspecified) (4% to 8%), pruritus (2% to 6%), urticaria (1% or less), abnormal skin odor (2% or less), flushing (7% to 8%), and hot flashes (2% to 5%). During other clinical trial evaluations, the following dermatologic effects were reported in 0.1% to 1% of patients: alopecia, cellulitis, cyst, atopic dermatitis, erythematous rash, genital pruritus, maculopapular rash, pallor, photosensitivity reaction, psoriasis, pustular rash, and skin discoloration. Chloasma, folliculitis, hypertrichosis, piloerection, seborrhea, skin hypertrophy, lupus erythematosus rash, and skin ulcer were reported rarely (less than 0.1%). Allergy (unspecified) was reported in 3% to 7% of adult and pediatric patients receiving clomipramine during clinical trials for obsessive-compulsive disorder compared to 3% to 5% of patients receiving placebo. Allergic reactions to tricyclic antidepressants such as clomipramine can include photosensitivity, vasculitis, erythema, urticaria, and/or pruritus. Fever may occur as part of an allergic reaction or as a symptom of blood dyscrasia or other event; fever occurred in more adults receiving clomipramine than placebo (4% vs. 0%) but in less pediatric patients receiving clomipramine than placebo (2% vs. 7%). There have been rare cases of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in patients treated with clomipramine. DRESS typically, although not exclusively, presents with fever, rash, and/or lymphadenopathy, in association with other organ system involvement, such as hepatitis, nephritis, hematologic abnormalities, myocarditis, or myositis sometimes resembling an acute viral infection. Eosinophilia is often present. The disorder is variable in its expression, and other organ systems may also be involved. Early manifestations of hypersensitivity (e.g., fever, lymphadenopathy) may be present even though rash is not evident. If DRESS develops, clomipramine should be discontinued immediately and the appropriate medical treatment should be initiated.
The effects of tricyclic antidepressants on the endocrine system can cause sexual dysfunction including libido decrease, impotence (erectile dysfunction), testicular swelling, ejaculation dysfunction (inhibited, delayed, or painful ejaculation), orgasm dysfunction, orgasm precipitated by yawning, breast enlargement, and galactorrhea in females or gynecomastia in males. During clinical trials in adults and children with obsessive-compulsive disorder, the following genitourinary (GU) or reproductive effects occurred more frequently in patients receiving clomipramine than placebo: micturition disorder (4% to 14%), urinary tract infection (6% or less), increased urinary frequency (5% or less), urinary retention (2% to 7%), cystitis (2% or less), galactorrhea (4% or less), menstrual disorder (4% or less), vaginitis (2% or less), leukorrhea (2% or less), breast enlargement (2% or less), mastalgia (1% or less), amenorrhea (1% or less), ejaculation dysfunction (42% adults, 6% pediatrics), erectile dysfunction (impotence) (adults, 20%), and libido change (adults, 21%). During other clinical trial evaluations, the following GU or reproductive effects were reported in 0.1% to 1% of patients: endometriosis, epididymitis, hematuria, nocturia, oliguria, ovarian cyst, perineal pain, polyuria, prostatic disorder, renal calculus, renal pain, urethral disorder, urinary incontinence, uterine hemorrhage, and vaginal bleeding. Rarely reported effects (less than 0.1%) included proteinuria, anorgasmy, breast engorgement, breast fibroadenosis, cervical dysplasia, endometrial hyperplasia, gynecomastia, premature ejaculation, pyelonephritis, pyuria, renal cyst, uterine inflammation, and vulvar disorder. Other endocrine effects included hypothyroidism (0.1% to 1%); goiter and hyperthyroidism were rare (less than 0.1%).
During clinical trials in adults and children with obsessive-compulsive disorder, the following adverse hematologic effect occurred more frequently in patients receiving clomipramine versus placebo: purpura (<= 3% vs 0%). During other clinical trial evaluations, lymphadenopathy was reported in 0.1-1% of patients. Rarely reported effects (< 0.1%) included leukemoid reaction, lymphoma-like disorder, and bone marrow suppression. Leukopenia, agranulocytosis, thrombocytopenia, anemia, and pancytopenia have been reported during post-market use. In patients who develop fever and sore throat during treatment with clomipramine, a thorough evaluation including a complete blood count (CBC) should be performed.
Patients receiving prolonged therapy with tricyclic antidepressants such as clomipramine can experience withdrawal symptoms following abrupt discontinuation of the tricyclic antidepressant. Symptoms of cholinergic rebound such as insomnia, dizziness, abdominal pain, nausea, vomiting, or diarrhea can occur. It is common for patients to experience at least one of these symptoms (e.g., insomnia, nausea) on abrupt discontinuation, but infrequent for many of them to manifest together. When possible, gradual tapering of the tricyclic is recommended if treatment is discontinued.
Very rare cases of serotonin syndrome have been reported when tricyclic antidepressants such as clomipramine are administered concomitantly with other medications known to cause serotonin syndrome, particularly with SSRIs. Tricyclic antidepressants act, in part, as inhibitors of serotonin reuptake. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. More than 30 cases of hyperthermia have been reported during post-market use of clomipramine, primarily during co-administration of other drugs. Some cases involving concurrent use of clomipramine and a neuroleptic were considered to be neuroleptic malignant syndrome.
During clinical trials in adults and children with obsessive-compulsive disorder, the following respiratory effects occurred more frequently in patients receiving clomipramine than placebo: pharyngitis (<= 14% vs 5-9%), rhinitis (7-12% vs 9-10%), sinusitis (2-6% vs 4-5%), bronchospasm (2-7% vs <= 2%), dyspnea (<= 2% vs 0%), and laryngitis (<= 2% vs <= 1%). During other clinical trial evaluations, the following respiratory effects were reported in 0.1-1% of patients: bronchitis, hyperventilation, increased sputum, and pneumonia. Cyanosis, hemoptysis, hypoventilation, and laryngospasm were reported rarely (< 0.1%)
During clinical trials in adults and children with obsessive-compulsive disorder, the following adverse musculoskeletal effects occurred more frequently in patients receiving clomipramine than placebo: myalgia (<= 13% vs <= 9%) and myasthenia (1-2% vs 0%). During other clinical trial evaluations, arthrosis was reported in 0.1-1% of patients. Rarely reported effects (< 0.1%) included exostosis, hematoma, myopathy, myositis, and polyarteritis nodosa.
During clinical trials in adults and children with obsessive-compulsive disorder, the following general effects occurred in patients receiving clomipramine compared to placebo: fatigue (35-39% vs 9-18%), unspecified pain (3-4% vs 2%), chills (<= 2% vs <= 1%), and asthenia (<= 2% vs 0%). During other clinical trial evaluations, the following general effects were reported in 0.1-1% of patients: general edema, increased susceptibility to infection, and malaise. Dependent edema was reported rarely (< 0.1%).
Clomipramine can cause hyponatremia, which is frequently thought to result from the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Elderly patients, those receiving diuretics or prone to dehydration, and those who are otherwise volume depleted (e.g., hypovolemia) appear to be at greatest risk. Hyponatremia may manifest as headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness which may result in falls. Severe manifestations include hallucinations, syncope, seizure, coma, respiratory arrest, and death. Clomipramine should be discontinued in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.
During clinical trial evaluation of clomipramine, the following metabolic or nutritional effects were reported in 0.1-1% of patients: dehydration, diabetes mellitus, gout, hypercholesterolemia, hyperglycemia, hyperuricemia, and hypokalemia. Rarely reported effects (< 0.1%) included fat intolerance and glycosuria. Because tricyclics can affect blood glucose concentrations, clomipramine should be used with caution in patients with diabetes mellitus.
During pre-market evaluation of clomipramine, elevated hepatic enzymes to greater than 3 times the upper limit of normal were observed in 1-3% of patients. Most cases were not associated with clinical findings of hepatic injury. However, fatal hepatic injury has been reported during post-market use. Hepatitis was reported in 0.1-1% of patients during clinical trial evaluation. Caution is advisable during use of clomipramine in the presence of liver disease; periodic monitoring of liver enzymes is recommended in such instances.
Clomipramine is contraindicated in patients with a hypersensitivity to clomipramine or with a tricyclic antidepressant hypersensitivity. Alternative therapy should be considered in patients with tricyclic antidepressant hypersensitivity. Rare cases of drug rash with eosinophilia and systemic symptoms (DRESS) have been reported with the use of clomipramine. In the event of serious rash or severe acute reactions such as DRESS, discontinue clomipramine therapy immediately and institute appropriate treatment. Tricyclic antidepressants may also display cross-sensitivity in patients with a carbamazepine hypersensitivity. The potential for cross-reactivity between tricyclics and other structurally similar compounds such as cyclobenzaprine or tetracyclic antidepressants (e.g., maprotiline, amoxapine) has not been established.
The use of monoamine oxidase inhibitor therapy (MAOI therapy intended to treat psychiatric disorders) with clomipramine or within 14 days of stopping treatment with clomipramine is contraindicated because of an increased risk of serotonin syndrome. The use of clomipramine within 14 days of discontinuing MAOI therapy is also contraindicated. Starting clomipramine in a patient who is being treated with linezolid or intravenous methylene blue is also contraindicated because of an increased risk of serotonin syndrome.
Clomipramine is contraindicated in patients who are in the acute recovery phase following acute myocardial infarction; use of clomipramine could cause sudden death. Use with caution in patients with preexisting hypotension. Also, use tricyclic antidepressants (TCAs) with caution and with close monitoring in patients with any cardiac disease (e.g., heart failure, history of myocardial infarction, congenital heart disease). Clomipramine may cause orthostatic hypotension, particularly in the initial dosing titration. Modest orthostatic decreases in blood pressure and modest tachycardia were each seen in approximately 20% of patients taking clomipramine in clinical trials, but patients were frequently asymptomatic. TCAs, including clomipramine, particularly when given in high doses, have been reported to produce arrhythmias, sinus tachycardia, and prolongation of the conduction time. Myocardial infarction and stroke have been reported with drugs of this class. Although the risk of cardiovascular adverse events is higher after acute overdose, patients with cardiovascular disease should be closely monitored via ECGs and clinical exams. TCAs should not be given to patients with QT prolongation. Use clomipramine with caution in patients with conditions that may increase the risk of QT prolongation including congenital long QT syndrome, bradycardia, AV block, heart failure, stress-related cardiomyopathy, myocardial infarction, stroke, hypomagnesemia, hypokalemia, hypocalcemia, or in patients receiving medications known to prolong the QT interval or cause electrolyte imbalances. Females, people 65 years and older, patients with sleep deprivation, adrenal gland tumors, sickle cell disease, decreased thyroid function, hyperparathyroidism, hypothermia, systemic inflammation (e.g., human immunodeficiency virus (HIV) infection, fever, and some autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus (SLE), and celiac disease) and patients undergoing apheresis procedures (e.g., plasmapheresis [plasma exchange], cytapheresis) may also be at increased risk for QT prolongation. There have been reports of sudden death in pediatric patients treated with TCAs that were not associated with overdoses. Although cardiac monitoring is recommended, it is unclear whether monitoring can prevent a sudden death event. The American Heart Association recommends conducting a detailed patient and family history and physical examination prior to initiating ADHD pharmacologic treatment, and obtaining a baseline ECG is a reasonable addition to the initial evaluation. Once the medication is started, a repeat ECG may be helpful if the original ECG was obtained before the child was 12 years old, if cardiac symptoms develop, or there is a change in family history. If a child or adolescent has any significant findings on physical examination, ECG, or family history, a pediatric cardiologist should be consulted before the medication is initiated.
Long-term safety and effectiveness have been established for use of clomipramine in pediatric patients 10 to 17 years old for the treatment of obsessive compulsive disorder (OCD). There are limited data on the use of clomipramine in pediatric patients for other indications. Clomipramine is not indicated for the treatment of major depressive disorder (MDD) in pediatric patients. In a pooled analysis of placebo-controlled trials of antidepressants (n = 4,500 pediatrics and 77,000 adults), there was an increased risk for suicidal thoughts and behaviors in children, adolescent, and young adult patients 24 years of age and younger receiving an antidepressant versus placebo, with considerable variation in the risk of suicidality among drugs. The difference in absolute risk of suicidal thoughts and behaviors across different indications was highest in those with major depression. The need for an antidepressant in children, adolescents, or young adults for any use must be weighed against the risk of suicidality; it is unknown if this risk extends to long-term use. All patients should be monitored for symptom worsening or suicidality, especially at treatment initiation or after dose changes. Caregivers and/or patients should immediately notify the prescriber of changes in behavior or suicidal ideation. A change to the treatment regimen or discontinuation of clomipramine may be necessary in patients with emerging suicidality or worsening depression. Clomipramine should be used with caution in children with a known family history of heart disease or who are taking medications that cause QT prolongation. QTc interval prolongation, tachycardias, and other side effects have been reported in children who have taken tricyclic antidepressants (TCAs); there are rare reports of deaths due to cardiovascular side effects. Routine cardiovascular monitoring has been suggested for children receiving TCAs due to the potential of these agents to produce adverse cardiac effects.
All effective antidepressants can transform depression into mania or hypomania in predisposed individuals. It is generally believed (though not established in controlled trials) that treating such an episode with an antidepressant alone may increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. If a patient develops manic symptoms, clomipramine should be withheld and appropriate therapy initiated to treat the manic symptoms. Additionally, depression may be the presenting symptom of a mixed/manic episode of bipolar disorder. Patients should be adequately screened for bipolar disorder prior to initiating an antidepressant. Such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. Patients with depression or comorbid depression in the setting of other psychiatric illness being treated with antidepressants should be observed for clinical worsening and suicidality, especially during the initial few months of a course of drug therapy, or at times of dose changes. Clomipramine may precipitate an acute psychotic episode in patients with unrecognized schizophrenia. Caregivers should be advised to closely observe the patient on a daily basis and to communicate immediately with the prescriber the emergence of unusual changes in behavior or suicidality. The following symptoms, anxiety, agitation, panic attacks, insomnia, irritability, hostility, aggressiveness, impulsivity, akathisia (psychomotor restlessness), hypomania, and mania, have been reported in adult and pediatric patients being treated with antidepressants for major depressive disorder as well as for other indications, both psychiatric and nonpsychiatric. Although a causal link between the emergence of such symptoms and either the worsening of depression and/or the emergence of suicidal impulses has not been established, there is concern that such symptoms may represent precursors to emerging suicidality. It should be noted that clomipramine is not approved for use in treating bipolar depression.
Clomipramine can induce significant sedation, particularly during the initiation of treatment. Clomipramine may enhance the response to alcohol, the effects of barbiturates, and increase sedation or central nervous system (CNS) effects during coadministration with other CNS depressants. Patients should use caution with ethanol ingestion. In patients who may use alcohol excessively (e.g., alcoholism), the potentiation of CNS effects may increase the danger inherent in any suicide attempt or overdosage. Patients should use caution when driving or operating machinery until they are aware of the effects of the medication.
Clomipramine should be used with caution in patients with a preexisting seizure disorder because tricyclic antidepressants (TCAs) can lower the seizure threshold. If seizures occur during TCA therapy, the TCA should be discontinued. Concurrent administration of clomipramine and electroconvulsive therapy (ECT) may increase the hazards associated with such therapy. Such treatment should be limited to patients for whom it is essential.
Tricyclic antidepressants (TCAs) such as clomipramine should be used with caution in patients with hepatic disease and periodic monitoring of hepatic enzyme levels is recommended in such patients. The effects of hepatic impairment on the disposition of clomipramine have not been determined. Poor metabolizers of CYP2D6 have higher than expected plasma concentrations of tricyclic antidepressants (TCAs) when given usual doses; use with caution in patients who are CYP2D6 PMs. During premarketing testing, clomipramine was occasionally associated with elevations of liver enzymes (SGOT and SGPT) of potential clinical importance (i.e., values greater than 3 times the upper limit of normal). In the vast majority of instances, these enzyme increases were not associated with other clinical findings suggestive of hepatic injury; moreover, none were jaundiced. Rare reports of more severe liver injury, some fatal, have been recorded in foreign postmarketing experience.
Prior to elective surgery with general anesthetics, therapy with clomipramine should be discontinued for as long as is clinically feasible, and the anesthetist should be advised.
The anticholinergic effects of tricyclic antidepressants (TCAs) limit the use of the drugs in certain patients. The anticholinergic effects of clomipramine may be additive with other anticholinergic medications. These actions can decrease GI motility, causing constipation and in some cases, paralytic ileus. Patients who have risk factors for urinary retention, such as those with benign prostatic hypertrophy, should also be treated with caution. Anticholinergic effects appear most frequently and cause the greatest morbidity in elderly patients.
Caution is recommended when prescribing clomipramine to patients with controlled closed-angle glaucoma. The pupillary dilation that can occur with antidepressants may precipitate a closed-angle glaucoma attack in patients with anatomically narrow angles who do not have a patent iridectomy. An acute attack of closed-angle glaucoma is considered a medical emergency because the increased intraocular pressure is rapid and severe, and may quickly result in blindness if left untreated. The anticholinergic effects of clomipramine may increase lens discomfort for wearers of contact lenses. Mydriasis, disturbance of accommodation, and dry eyes may contribute to blurred vision and lens intolerance. The use of lubricating drops may be necessary.
Clomipramine can cause hyponatremia, which is frequently thought to result from the syndrome of inappropriate antidiuretic hormone secretion (SIADH). Elderly patients, those receiving diuretics or prone to dehydration, and those who are otherwise volume depleted (e.g., hypovolemia) appear to be at greatest risk. Clomipramine should be discontinued in patients with symptomatic hyponatremia and appropriate medical intervention should be instituted.
Although no instances of severe hematologic toxicity were seen in the premarketing experience with clomipramine, there have been postmarketing reports of leukopenia, agranulocytosis, thrombocytopenia, anemia, and pancytopenia in association with clomipramine use. As is the case with other tricyclic antidepressants, leukocyte and differential blood counts should be obtained in patients who develop fever and sore throat during treatment.
Tricyclic antidepressants (TCAs) like clomipramine should be used with caution in patients who have thyroid disease. Close supervision is required when clomipramine is given to patients with hyperthyroidism or to patients with hypothyroidism who are receiving thyroid medication. Hypothyroidism may increase the risk for developing a prolonged QT interval when using clomipramine.
Tricyclic antidepressants (TCAs) affect blood glucose concentrations because of their effect on the endocrine system; both elevation and lowering of blood sugar levels have been reported. Therefore, clomipramine should be used with caution in patients with diabetes mellitus. TCAs should also be used with caution in patients with tumors of the adrenal medulla (e.g., pheochromocytoma, neuroblastoma) in whom these drugs may provoke hypertensive crises. Pheochromocytoma may also increase the risk for developing a prolonged QT interval when using clomipramine.
Similar to other tricyclic antidepressants (TCAs), clomipramine lowers the seizure threshold. Because of a potential increased risk of seizures, TCAs should not be used during intrathecal radiographic contrast administration. Tricyclic antidepressant therapy should be discontinued 48 hours before and not restarted for at least 24 hours after myelography.
Patients may be more prone to sunburn during therapy with clomipramine. Patients should avoid excessive exposure to sunlight since there have been reports of photosensitization during the use of tricyclic antidepressants (TCAs). Suitable precautions should be taken to limit effects prior to sunlight (UV) exposure, such as wearing long-sleeved clothing and a hat, and using sunscreens.
The manufacturer recommends that clomipramine be used with caution in patients with severe renal impairment or renal failure; the effects of renal impairment on the disposition of clomipramine have not been determined.
Following prolonged therapy, abrupt discontinuation of a tricyclic antidepressant (TCA) should be avoided because it could precipitate a drug discontinuation syndrome. Symptoms of cholinergic rebound such as nausea, vomiting, or diarrhea may occur. Other typical symptoms of antidepressant discontinuation syndrome include flu-like symptoms, insomnia, imbalance, sensory disturbances, and hyperarousal. A variety of withdrawal symptoms have been reported in association with abrupt discontinuation of clomipramine, including dizziness, nausea, vomiting, headache, malaise, sleep disturbance, hyperthermia, and irritability. In addition, such patients may experience a worsening of psychiatric status. While the withdrawal effects have not been systematically evaluated in controlled trials, they are well known with TCAs, and it is recommended that the dosage be tapered gradually and the patient monitored carefully during discontinuation.
Use of clomipramine should be cautious in geriatric adults; initiate at the low end of the dosage range, with slow dosage titration and careful monitoring. Geriatric adults are particularly sensitive to the anticholinergic side effects of TCAs and may be at increased risk for falls. According to the Beers Criteria, tricyclic antidepressants (TCAs) are considered potentially inappropriate medications (PIMs) in geriatric adults; avoid due to the potential for orthostatic hypotension, anticholinergic effects or toxicity, or sedation. Avoid TCA use in those with the following conditions due to the potential for symptom exacerbation or adverse effects: syncope (increased risk of orthostatic hypotension or bradycardia), dementia/cognitive impairment (drug-induced CNS effects), delirium/high risk of delirium (new-onset or worsening delirium), or lower urinary tract symptoms/benign prostatic hyperplasia in men (urinary retention or hesitancy). Also, avoid TCA use in those with a history of falls or fractures, unless safer alternatives are not available, since TCAs can produce ataxia, impaired psychomotor function, syncope, and additional falls. If a TCA must be used, consider reducing use of other CNS-active medications and implement other strategies to reduce fall risk. Lastly, TCAs can cause or exacerbate hyponatremia and SIADH and the older adult is at increased risk of developing these conditions. Sodium levels should be closely monitored when starting or changing dosages. The U.S. Omnibus Budget Reconciliation Act (OBRA) regulates the use of antidepressants in residents of long-term care facilities (LTCFs). TCAs are rarely medications of choice in the older adult. However, TCAs may be appropriate for selected conditions when safer medications or interventions are either not indicated or have been considered, attempted, and failed. When a TCA is being used to manage behavior, stabilize mood, or treat a psychiatric disorder, the facility should attempt to taper the medication as outlined in the OBRA guidelines, unless a taper is clinically contraindicated. Dosages and durations of treatment used in the geriatric adult should be in accordance with prescribing labels, published literature recommendations, and expert guidelines.
There are no adequate or well-controlled studies regarding the use of clomipramine in pregnant women; clomipramine should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. Tricyclic antidepressants (TCAs) cross the placenta. Although animal studies have not shown evidence of teratogenicity with clomipramine, the drug may be associated with an increased risk of teratogenicity in humans when used maternally during early pregnancy, primarily related to cardiovascular defects. Neonatal complications after in utero exposure to TCAs including withdrawal symptoms, hypoglycemia, respiratory diagnoses, developmental delays, and jaundice have been reported. Neonatal withdrawal symptoms have included lethargy, cyanosis, tachypnea with respiratory acidosis, jitteriness, tremors, hypertonia, hypotonia, feeding difficulties, and seizures. Neonates exhibiting signs or symptoms of drug toxicity or withdrawal should be carefully monitored. The impact of in utero exposure to antidepressants or antipsychotics compared to no psychotropic exposure was assessed in infants 6 months of age using the Infant Neurological International Battery (INFANIB), a neuromotor exam that tests posture, tone, reflexes, and motor skills, and using a visual habituation paradigm of a neutral female face. The infants exposed to antipsychotics (n = 22) showed significantly lower INFANIB scores than those exposed to an antidepressant (n = 202) or no psychotropic drug (n = 85). There were no significant differences regarding habituation between the medication exposure groups. In a prospective trial evaluating the effects of in utero exposure to tricyclic or tetracyclic antidepressants in infants 15 to 71 months of age compared to similar non-exposed controls, exposure to antidepressants did not adversely affect IQ, language, behavior, or temperament. The effects of clomipramine on labor and obstetric delivery are unknown. There is a pregnancy exposure registry that monitors outcomes in pregnant patients exposed to clomipramine; information about the registry can be obtained at womensmentalhealth.org/clinical-and-research-programs/pregnancyregistry/ or by calling 1-866-961-2388.
Clomipramine is excreted into breast milk, and the manufacturer recommends that a decision be made whether to discontinue nursing or to discontinue the drug taking into account the importance of the drug to the mother. In a small study comparing 10 breast-fed infants exposed to a tricyclic antidepressant through nursing to a similar group of 15 bottle-fed infants, the milk:maternal plasma ratios were 0.4 to 1.2 and 0.4 to 3, respectively. Overall, the daily doses of tricyclics ingested by the breast-fed infants were about 1% of the maternal dose per kg. Detectable amounts of drug were found in the plasma of one of the two infants exposed to clomipramine; however, no developmental delays or other adverse effects were noted in either of the infants. Due to individual variability in response to medications for obsessive-compulsive disorder (OCD), it may be prudent to continue the existing regimen if ongoing treatment is deemed necessary during breast-feeding. However, because a pooled analysis found that maternal use of sertraline and paroxetine usually produced undetectable or low drug concentrations in infant serum, these agents may be the preferred agents when initiating OCD therapy in a breast-feeding mother. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. If a breast-feeding infant experiences an adverse effect related to a maternally ingested drug, healthcare providers are encouraged to report the adverse effect to the FDA.
Tobacco smoking has been shown to increase the clearance of TCAs such as clomipramine, by inducing hepatic microsomal enzymes. Plasma concentrations of clomipramine were significantly lower in smokers than in nonsmokers. The effect of tobacco on hepatic microsomal enzymes is not related to the nicotine component, so sudden smoking cessation may result in a reduced clearance of TCAs and increased TCA effects, despite the initiation of nicotine replacement products.
For treatment of obsessive-compulsive disorder (OCD):
Oral dosage:
Adults: Initially, 25 mg PO once daily, may gradually increase in the first 2 weeks to 100 mg/day PO, given in divided doses. During initial titration, daily dose should be given in divided doses with meals to reduce gastrointestinal side effects. Max: 250 mg/day. After titration, the total daily dose may be given every night at bedtime to minimize daytime sedation.
Children and Adolescents 10 years and older: Initially, 25 mg PO once daily, gradually increasing up to a total of 100 mg/day PO given in divided doses; or 3 mg/kg/day given in divided doses, whichever is the smaller, over the first 2 weeks. These initial doses should be divided and taken with meals to reduce gastrointestinal side effects. After the initial titration, the dosage may be increased further gradually over the next several weeks up to a daily maximum of 3 mg/kg/day or 200 mg/day, whichever is smaller. After titration, the total daily dose may be given every night at bedtime to minimize daytime sedation. In clinical trials in pediatric patients for OCD, the average effective dose range was 100 to 200 mg/day.
For the treatment of behavioral symptoms associated with autistic disorder*:
Oral dosage:
Adults: Initially, 25 mg PO once daily. Increase if needed to 75 to 100 mg/day PO. Further titrate gradually if necessary. Max: 250 mg/day PO.
Children and Adolescents: Initially, 25 mg PO once daily. May increase gradually to 200 mg/day PO or to 3 mg/kg/day PO, whichever is less.
For the treatment of premature ejaculation*:
Oral dosage:
Adult males: 25 to 50 mg/day PO has been shown to increase ejaculatory latency and other measures of premature ejaculation (PE) and is suggested per treatment guidelines; beneficial effects as well as adverse event rates appear to be dose-related. In one study, men with baseline mean ejaculatory latency of 81 seconds were randomized to receive 25 mg/day of clomipramine, 50 mg/day of clomipramine, or placebo. Clomipramine therapy was associated with marked improvement: 25 mg/day of clomipramine increased ejaculatory latency to 202 seconds and 50 mg/day of clomipramine to 419 seconds.
Alternatively, 25 mg PO given 4 to 24 hours pre-intercourse has demonstrated efficacy and is suggested per treatment guidelines. It is unclear if daily or situational dosing is more effective in the management of PE. Likewise, the optimal interval for situational dosing before intercourse is not well defined. The choice of regimen is ultimately defined by clinical judgement and patient preference in light of the frequency of sexual activity.
Maximum Dosage Limits:
-Adults
250 mg/day PO.
-Elderly
250 mg/day PO.
-Adolescents
3 mg/kg/day PO or 200 mg/day PO, whichever is smaller.
-Children
>= 10 years: 3 mg/kg/day PO or 200 mg/day PO, whichever is smaller.
< 10 years: Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; but dosage adjustments may be necessary. In dosing clomipramine in patients with liver disease, use caution by using the lower initial doses and titrating slowly to patient clinical response and tolerance.
Patients with Renal Impairment Dosing
Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed for patients with mild or moderate impairment. The manufacturer recommends that clomipramine be used with caution in patients with severe renal impairment or renal failure as the effects of renal impairment on the disposition of clomipramine or its metabolites have not been determined.
*non-FDA-approved indication
Abiraterone: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if coadministration with abiraterone is necessary; a dose reduction of clomipramine may be necessary. Clomipramine is a CYP2D6 substrate and abiraterone is a moderate CYP2D6 inhibitor. Patients who are stable on a given dose of clomipramine may become abruptly toxic when given abiraterone is concomitant therapy.
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Acetaminophen; Aspirin: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Acetaminophen; Caffeine; Dihydrocodeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Acetaminophen; Caffeine; Pyrilamine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Acetaminophen; Chlorpheniramine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Acetaminophen; Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Acetaminophen; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of doxylamine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Diphenhydramine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Acetaminophen; Guaifenesin; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Acetaminophen; Hydrocodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Acetaminophen; Oxycodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Acetaminophen; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Acetaminophen; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Acetazolamide: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions.
Acetylcholine Chloride: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Acrivastine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Acyclovir: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of acyclovir is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and acyclovir is a CYP1A2 inhibitor.
Adagrasib: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with adagrasib is necessary; a dose reduction of TCA may be necessary. Concurrent use may increase the exposure of TCAs which are CYP2D6 substrates; adagrasib is a CYP2D6 inhibitor.
Alfentanil: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Allopurinol: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of allopurinol is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and allopurinol is a CYP1A2 inhibitor.
Almotriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Alosetron: (Moderate) Alosetron, if combined with drugs that possess anticholinergic properties like tricyclic antidepressants, may seriously worsen constipation, leading to events such as GI obstruction/impaction or paralytic ileus.
Alprazolam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Amantadine: (Moderate) Additive anticholinergic effects and CNS effects may be seen when tricyclic antidepressants are used concomitantly with amantadine.
Amifampridine: (Major) Carefully consider the need for concomitant treatment with tricyclic antidepressants and amifampridine, as coadministration may increase the risk of seizures. If coadministration occurs, closely monitor patients for seizure activity. Seizures have been observed in patients without a history of seizures taking amifampridine at recommended doses. Tricyclic antidepressants may increase the risk of seizures.
Amiodarone: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of amiodarone is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and amiodarone is a CYP1A2 inhibitor.
Amlodipine; Celecoxib: (Moderate) A dosage adjustment may be warranted for clomipramine if coadministered with celecoxib due to the potential for celecoxib to enhance the exposure and toxicity of clomipramine. Celecoxib is a CYP2D6 inhibitor, and clomipramine is a CYP2D6 substrate.
Amobarbital: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Amoxapine: (Major) The use of a heterocyclic antidepressant, such as amoxapine, with tricyclic antidepressants (TCAs) is not generally recommended due to the duplicative nature of therapy and the risk for side effects. Additive cardiac effects (e.g., tachycardia), CNS effects, or antimuscarinic effects may occur. Additive dry mouth, constipation, drowsiness, bladder difficulties, or changes in heart rate might be possible.
Amoxicillin; Clarithromycin; Omeprazole: (Minor) Coadministration may result in increased clomipramine exposure. Omeprazole is a CYP2C19 inhibitor and clomipramine is a CYP2C19 substrate.
Amphetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Amphetamine; Dextroamphetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Amphetamines: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Anagrelide: (Moderate) Torsade de pointes (TdP) and ventricular tachycardia have been reported with anagrelide. In addition, dose-related increases in mean QTc and heart rate were observed in healthy subjects. A cardiovascular examination, including an ECG, should be obtained in all patients prior to initiating anagrelide therapy. Monitor patients during anagrelide therapy for cardiovascular effects and evaluate as necessary. Tricyclic antidepressants are associated with a possible risk for QT prolongation and TdP and should be used cautiously with anagrelide.
Apomorphine: (Moderate) Use apomorphine and tricyclic antidepressants together with caution due to the risk of additive QT prolongation. Tricyclic antidepressants have been associated with QT prolongation, primarily in overdosage or when excessive plasma concentrations are encountered. Dose-related QTc prolongation is associated with therapeutic apomorphine exposure. Additive sedation is also possible during combined use of these agents.
Apraclonidine: (Moderate) Tricyclic antidepressants have been reported to blunt the hypotensive effects of systemic clonidine; it is not known whether or not the concomitant use of these agents with apraclonidine can reduce the intraocular pressure lowering effect.
Aprepitant, Fosaprepitant: (Major) Use caution if clomipramine and aprepitant are used concurrently and monitor for an increase in clomipramine-related adverse effects for several days after administration of a multi-day aprepitant regimen. After administration, fosaprepitant is rapidly converted to aprepitant and shares the same drug interactions. Clomipramine is a CYP3A4 substrate. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer; substitution of fosaprepitant 115 mg IV on day 1 of the 3-day regimen may lessen the inhibitory effects of CYP3A4. The AUC of a single dose of another CYP3A4 substrate, midazolam, increased by 2.3-fold and 3.3-fold on days 1 and 5, respectively, when coadministered with a 5-day oral aprepitant regimen. After a 3-day oral aprepitant regimen, the AUC of midazolam increased by 25% on day 4, and decreased by 19% and 4% on days 8 and 15, respectively, when given on days 1, 4, 8, and 15. As a single 40-mg oral dose, the inhibitory effect of aprepitant on CYP3A4 is weak, with the AUC of midazolam increased by 1.2-fold; the midazolam AUC increased by 1.5-fold after a single 125-mg dose of oral aprepitant. After single doses of IV fosaprepitant, the midazolam AUC increased by 1.8-fold (150 mg) and 1.6-fold (100 mg); less than a 2-fold increase in the midazolam AUC is not considered clinically important.
Aripiprazole: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of aripiprazole and tricyclic antidepressants due to the risk for additive CNS depression.
Armodafinil: (Moderate) In vitro data indicate that armodafinil is an inhibitor of CYP2C19. In theory, dosage reductions may be required for drugs that are largely eliminated via CYP2C19 metabolism such as clomipramine during coadministration with armodafinil.
Artemether; Lumefantrine: (Major) Artemether; lumefantrine is an inhibitor and the tricyclic antidepressants are substrates of the CYP2D6 isoenzyme; therefore, coadministration may lead to increased tricyclic antidepressant concentrations. Furthermore, although there are no studies examining the effects of artemether; lumefantrine in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation. Concomitant use of artemether; lumefantrine with drugs that may prolong the QT interval such as tricyclic antidepressants should be avoided. Consider ECG monitoring if tricyclic antidepressants must be used with or after artemether; lumefantrine treatment.
Articaine; Epinephrine: (Major) Avoid use of epinephrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the vasopressor effects of epinephrine.
Asenapine: (Moderate) Concurrent use of asenapine and tricyclic antidepressants should be avoided if possible. Asenapine has been associated with a risk for QT prolongation and torsade de pointes, and tricyclics at elevated serum concentrations may produce clinically significant prolongation of the QTc interval. In addition, there is a potential for other interactions, such as augmentation of CNS impairment or orthostatic hypotension. Further, in vitro studies indicate that CYP1A2 and CYP3A4 are involved in the metabolism of asenapine. Inhibitors of these isoenzymes such as imipramine may decrease the elimination of asenapine. During co-administration of a single 75 mg dose of imipramine and a single 5 mg dose of asenapine, the Cmax of asenapine was increased by 17% and the AUC was increased by 10%. No asenapine dose adjustments are required during combined use.
Aspirin, ASA: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Aspirin, ASA; Caffeine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Moderate) Orphenadrine should be combined cautiously with tricyclic antidepressants due to the potential for additive anticholinergic and CNS depressant effects. Antimuscarinic effects might be seen on GI smooth muscle, bladder function, the eye, and temperature regulation. Consider an alternative skeletal muscle relaxant.
Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Moderate) Concomitant use of carisoprodol with tricyclic antidepressants can result in additive CNS depression (sedation and dizziness), which can impair the ability to undertake tasks requiring mental alertness.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Aspirin, ASA; Dipyridamole: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Aspirin, ASA; Omeprazole: (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Minor) Coadministration may result in increased clomipramine exposure. Omeprazole is a CYP2C19 inhibitor and clomipramine is a CYP2C19 substrate.
Aspirin, ASA; Oxycodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed.
Atazanavir: (Moderate) According to the manufacturer, concurrent use of tricyclic antidepressants (TCAs) and atazanavir may result in elevated TCA plasma concentration, and could increase the potential for serious adverse effects. If these drugs are administered together, carefully titrate the TCA dose based on a clinical assessment of antidepressant response. Patients on a stable dose of TCA who start treatment with atazanavir should be monitored for TCA-associated anticholinergic effects (e.g., sedation, confusion, constipation). In addition to clinical monitoring, the manufacturer suggests obtaining TCA serum concentrations (where available) as an adjunct to assessing the potential for interactions.
Atazanavir; Cobicistat: (Moderate) According to the manufacturer, concurrent use of tricyclic antidepressants (TCAs) and atazanavir may result in elevated TCA plasma concentration, and could increase the potential for serious adverse effects. If these drugs are administered together, carefully titrate the TCA dose based on a clinical assessment of antidepressant response. Patients on a stable dose of TCA who start treatment with atazanavir should be monitored for TCA-associated anticholinergic effects (e.g., sedation, confusion, constipation). In addition to clinical monitoring, the manufacturer suggests obtaining TCA serum concentrations (where available) as an adjunct to assessing the potential for interactions. (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Atomoxetine: (Minor) Atomoxetine should be used cautiously with tricyclic antidepressants (TCAs) such as clomipramine as concurrent use may increase the risk of QT prolongation. QT prolongation has occurred during therapeutic use of atomoxetine and following overdose. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Atropine: (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Atropine; Difenoxin: (Moderate) Concurrent administration can potentiate the CNS and respiratory depressant effects of diphenoxylate/difenoxin and the CNS depressant effects of the tricyclic antidepressant (TCA). Both TCAs and diphenoxylate/difenoxin may cause constipation. Use caution during coadministration. Cases of severe GI reactions including toxic megacolon and adynamic ileus have been rarely reported. In some cases, a dosage reduction of diphenoxylate or difenoxin might be needed to manage any noted side effects. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Azelastine: (Moderate) Monitor for excessive sedation and somnolence during coadministration of azelastine and tricyclic antidepressants. Concurrent use may result in additive CNS depression.
Azelastine; Fluticasone: (Moderate) Monitor for excessive sedation and somnolence during coadministration of azelastine and tricyclic antidepressants. Concurrent use may result in additive CNS depression.
Baclofen: (Moderate) Monitor for unusual drowsiness and excess sedation during coadministration of baclofen and tricyclic antidepressants due to the risk for additive CNS depression.
Barbiturates: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Belladonna; Opium: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. The anticholinergic properties of tricyclic antidepressants may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome. Monitor for signs of urinary retention and reduced gastric motility. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and belladonna use. Concomitant use may result in additive anticholinergic adverse effects.
Benzhydrocodone; Acetaminophen: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. The anticholinergic properties of tricyclic antidepressants may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome. Monitor for signs of urinary retention and reduced gastric motility.
Benzodiazepines: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) According to the manufacturer of clomipramine, treatment initiation with clomipramine is contraindicated in patients currently receiving intravenous methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than clomipramine (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving clomipramine and requiring urgent treatment with intravenous methylene blue, clomipramine should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits of methylene blue outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Clomipramine may be re-initiated 24 hours after the last dose of methylene blue. Results from an in vitro study indicate that methylene blue is a potent, reversible inhibitor of the monoamine oxidase type A enzyme (MAO-A). MAO-A is responsible for the metabolism of serotonin; therefore, concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Clomipramine, a tricyclic antidepressant, is the most selective and potent inhibitor of serotonin within its class. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. One case report describes a patient receiving clomipramine who experienced jerky movements in all four limbs, as well as confusion and agitation after intravenous administration of methylene blue, with a return to her pre-operative state by day 4. Although the authors attribute this reaction to methylene blue toxicity, they did not exclude the possibility of a drug interaction based upon previous reports of an interaction between injectable methylene blue and selective serotonin reuptake inhibitors (SSRIs). Published interaction reports between intravenousely administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Signs and symptoms of serotonin syndrome include fever, diaphoresis, shivering, myoclonus, tremor, tachycardia, diarrhea, nausea, headache, incoordination, mental status changes (e.g., agitation, confusion), hyperreflexia, seizures, and coma. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Benzphetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Benztropine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and benztropine use. Concomitant use may result in additive anticholinergic adverse effects.
Berotralstat: (Moderate) Monitor for an increase in tricyclic antidepressant-related adverse reactions if coadministration with berotralstat is necessary; a dose reduction of the antidepressant may be necessary. Concurrent use may increase exposure of tricyclic antidepressants (TCAs). TCAs are CYP2D6 substrates and berotralstat is a CYP2D6 inhibitor.
Bethanechol: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Brexpiprazole: (Moderate) Due to the CNS effects of brexpiprazole, caution is advisable when brexpiprazole is given in combination with other centrally-acting medications including tricyclic antidepressants (TCAs). Sedation is generally more pronounced with tertiary TCAs such as amitriptyline, imipramine, doxepin, and clomipramine.
Brimonidine: (Moderate) Tricyclic antidepressants have been reported to decrease the antihypertensive effects of systemic clonidine. It is not known whether tricyclic antidepressants will affect the IOP-lowering efficacy of brimonidine eye solution. There are no data concerning the levels of systemic catecholamines after ophthalmic administration of brimonidine; however, monitor patients carefully who are taking brimonidine and tricyclic antidepressants.
Brimonidine; Brinzolamide: (Moderate) Tricyclic antidepressants have been reported to decrease the antihypertensive effects of systemic clonidine. It is not known whether tricyclic antidepressants will affect the IOP-lowering efficacy of brimonidine eye solution. There are no data concerning the levels of systemic catecholamines after ophthalmic administration of brimonidine; however, monitor patients carefully who are taking brimonidine and tricyclic antidepressants.
Brimonidine; Timolol: (Moderate) Tricyclic antidepressants have been reported to decrease the antihypertensive effects of systemic clonidine. It is not known whether tricyclic antidepressants will affect the IOP-lowering efficacy of brimonidine eye solution. There are no data concerning the levels of systemic catecholamines after ophthalmic administration of brimonidine; however, monitor patients carefully who are taking brimonidine and tricyclic antidepressants.
Brivaracetam: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Brompheniramine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Brompheniramine; Dextromethorphan; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Brompheniramine; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Brompheniramine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Bupivacaine Liposomal: (Major) Coadminister bupivacaine and tricyclic antidepressants together with caution. If epinephrine is added to bupivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient.
Bupivacaine: (Major) Coadminister bupivacaine and tricyclic antidepressants together with caution. If epinephrine is added to bupivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient.
Bupivacaine; Epinephrine: (Major) Avoid use of epinephrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the vasopressor effects of epinephrine. (Major) Coadminister bupivacaine and tricyclic antidepressants together with caution. If epinephrine is added to bupivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient.
Bupivacaine; Lidocaine: (Major) Coadminister bupivacaine and tricyclic antidepressants together with caution. If epinephrine is added to bupivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. (Major) If epinephrine is added to lidocaine for the purpose of infiltration and nerve block or spinal anesthesia, receipt of the product to a patient taking tricyclic antidepressants (TCA) may lead to severe, prolonged hypertension. In general, concurrent use of a local anesthetic solution containing epinephrine and a TCA should be avoided. If coadministration is necessary, careful patient monitoring is essential.
Bupivacaine; Meloxicam: (Major) Coadminister bupivacaine and tricyclic antidepressants together with caution. If epinephrine is added to bupivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient.
Buprenorphine: (Major) Concomitant use of tricyclic antidepressants (TCAs) and buprenorphine increases the risk of QT/QTc prolongation, torsade de pointes (TdP), serotonin syndrome, hypotension, profound sedation, coma, respiratory depression, or death. Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. In addition, concurrent use of opioids with other drugs that modulate serotonergic function, such as TCAs, has resulted in serotonin syndrome in some cases. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. If combination treatment is required, patients should be carefully observed, particularly during treatment initiation and during dose adjustments of the serotonergic drug; discontinue buprenorphine if serotonin syndrome is suspected. Lastly, concomitant use of buprenorphine with other CNS depressants, such as TCAs, can lead to additive CNS depressive effects. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of buprenorphine in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Evaluate the patient's use of alcohol or illicit drugs. Consider a dose reduction of one or both drugs. It is recommended that the injectable buprenorphine dose be halved for patients who receive other drugs with CNS depressant effects; for the buprenorphine transdermal patch, start with the 5 mcg/hour patch. Monitor patients for sedation or respiratory depression.
Buprenorphine; Naloxone: (Major) Concomitant use of tricyclic antidepressants (TCAs) and buprenorphine increases the risk of QT/QTc prolongation, torsade de pointes (TdP), serotonin syndrome, hypotension, profound sedation, coma, respiratory depression, or death. Avoid concomitant use if possible, especially in patients with additional risk factors for TdP. Consider taking steps to minimize the risk for QT/QTc interval prolongation and TdP, such as electrolyte monitoring and repletion and ECG monitoring, if concomitant use is necessary. In addition, concurrent use of opioids with other drugs that modulate serotonergic function, such as TCAs, has resulted in serotonin syndrome in some cases. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. If combination treatment is required, patients should be carefully observed, particularly during treatment initiation and during dose adjustments of the serotonergic drug; discontinue buprenorphine if serotonin syndrome is suspected. Lastly, concomitant use of buprenorphine with other CNS depressants, such as TCAs, can lead to additive CNS depressive effects. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of buprenorphine in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Evaluate the patient's use of alcohol or illicit drugs. Consider a dose reduction of one or both drugs. It is recommended that the injectable buprenorphine dose be halved for patients who receive other drugs with CNS depressant effects; for the buprenorphine transdermal patch, start with the 5 mcg/hour patch. Monitor patients for sedation or respiratory depression.
Bupropion: (Moderate) Use extreme caution when coadministering bupropion with other drugs that lower the seizure threshold, such as tricyclic antidepressants. Use low initial doses of bupropion and increase the dose gradually. Monitor patients for an increase in tricyclic antidepressant-related adverse reactions and signs and symptoms of serotonin syndrome during concomitant use, particularly during treatment initiation and dosage increases; a dose reduction of the tricyclic antidepressant may be necessary. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Tricyclic antidepressants are CYP2D6 substrates and bupropion is a CYP2D6 inhibitor.
Bupropion; Naltrexone: (Moderate) Use extreme caution when coadministering bupropion with other drugs that lower the seizure threshold, such as tricyclic antidepressants. Use low initial doses of bupropion and increase the dose gradually. Monitor patients for an increase in tricyclic antidepressant-related adverse reactions and signs and symptoms of serotonin syndrome during concomitant use, particularly during treatment initiation and dosage increases; a dose reduction of the tricyclic antidepressant may be necessary. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Tricyclic antidepressants are CYP2D6 substrates and bupropion is a CYP2D6 inhibitor.
Buspirone: (Moderate) Coadministration of buspirone with tricyclic antidepressants (TCAs) may increase the risk of serotonin syndrome. Both types of medications have serotonergic properties. Inform patients of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, all serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
Butalbital; Acetaminophen: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Butalbital; Acetaminophen; Caffeine: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Butalbital; Aspirin; Caffeine; Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Clomipramine may inhibit serotonin uptake by platelets, augmenting the antiplatelet effects of aspirin. This may increase the risk for an upper GI bleed. (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Butorphanol: (Moderate) Pain medications such as mixed opiate agonists/antagonists should be combined cautiously with tricyclic antidepressants due to the possibility of additive CNS depression, respiratory depression, hypotension, or decreased intestinal motility. Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering tricyclic antidepressants with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, tricyclic antidepressants and concurrent serotonergic agents should be discontinued. If a CNS depressant needs to be used with butorphanol, use the smallest effective dose and the longest dosing frequency of butorphanol.
Cabergoline: (Moderate) Cabergoline should not be coadministered with clomipramine, if possible. The prolactin-lowering effect of cabergoline may be diminished by medications that may increase prolactin levels such as clomipramine.
Cannabidiol: (Moderate) Monitor clomipramine plasma concentrations and consider a dose reduction of clomipramine as clinically appropriate, if adverse reactions occur when administered with cannabidiol. Increased clomipramine exposure is possible. Clomipramine is a CYP1A2 substrate and cannabidiol is a weak CYP1A2 inhibitor. Also monitor for excessive sedation and somnolence during coadministration of cannabidiol and clomipramine; additive CNS depression may occur.
Capivasertib: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with capivasertib is necessary; a dose reduction of TCA may be necessary. Concurrent use may increase the exposure of TCAs which are CYP2D6 substrates; capivasertib is a CYP2D6 inhibitor. Concomitant use has been observed to increase desipramine overall exposure by 2.1-fold.
Capmatinib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of capmatinib is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and capmatinib is a CYP1A2 inhibitor.
Capsaicin; Metaxalone: (Moderate) Coadministration of tricyclic antidepressants (TCAs) with metaxalone may result in additive CNS-depressant effects, such as sedation, and may increase the risk for serotonin syndrome. Use with caution and monitor for the emergence of excessive sedation or serotonin syndrome. If serotonin syndrome is suspected, serotonergic agents should be discontinued and appropriate medical treatment instituted.
Carbamazepine: (Moderate) Monitor for loss of tricyclic antidepressant efficacy during concomitant carbamazepine use. Concomitant use may result in decreased tricyclic antidepressant exposure.
Carbidopa; Levodopa: (Moderate) Monitor blood pressure and for symptoms of dyskinesia during concomitant levodopa and tricyclic antidepressant use. There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use.
Carbidopa; Levodopa; Entacapone: (Major) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including tricyclic antidepressants, due to the possibility of additive sedation. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment. Patients should be advised to avoid driving or other tasks requiring mental alertness until they know how the combination affects them. (Moderate) Monitor blood pressure and for symptoms of dyskinesia during concomitant levodopa and tricyclic antidepressant use. There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use.
Carbinoxamine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Cariprazine: (Moderate) Due to the CNS effects of cariprazine, caution is advisable when cariprazine is given in combination with other centrally-acting medications including tricyclic antidepressants. Sedation is generally more pronounced with tertiary agents such as amitriptyline, imipramine, doxepin, and clomipramine.
Carisoprodol: (Moderate) Concomitant use of carisoprodol with tricyclic antidepressants can result in additive CNS depression (sedation and dizziness), which can impair the ability to undertake tasks requiring mental alertness.
Celecoxib: (Moderate) A dosage adjustment may be warranted for clomipramine if coadministered with celecoxib due to the potential for celecoxib to enhance the exposure and toxicity of clomipramine. Celecoxib is a CYP2D6 inhibitor, and clomipramine is a CYP2D6 substrate.
Celecoxib; Tramadol: (Major) Concomitant use of tramadol with tricyclic antidepressants may cause respiratory depression, hypotension, profound sedation, and death and increase the risk for serotonin syndrome, seizures, and anticholinergic effects. Limit the use of opioid pain medications to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Monitor patients for serotonin syndrome if concomitant use is necessary, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Monitor for signs of urinary retention or reduced gastric motility during coadministration. The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. (Moderate) A dosage adjustment may be warranted for clomipramine if coadministered with celecoxib due to the potential for celecoxib to enhance the exposure and toxicity of clomipramine. Celecoxib is a CYP2D6 inhibitor, and clomipramine is a CYP2D6 substrate.
Cenobamate: (Moderate) Monitor for excessive sedation and somnolence during coadministration of cenobamate and tricyclic antidepressants. Concurrent use may result in additive CNS depression.
Ceritinib: (Minor) Periodically monitor electrolytes and ECGs in patients receiving concomitant treatment with ceritinib and clomipramine; an interruption of therapy, dose reduction, or discontinuation of therapy may be necessary if QT prolongation occurs. Ceritinib causes concentration-dependent prolongation of the QT interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Cetirizine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Cetirizine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Cevimeline: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorcyclizine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlordiazepoxide: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Chlordiazepoxide; Amitriptyline: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Chlordiazepoxide; Clidinium: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Chlorpheniramine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpheniramine; Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpheniramine; Dextromethorphan: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Chlorpheniramine; Hydrocodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpheniramine; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpheniramine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Chlorpromazine: (Moderate) During coadministration of tricyclic antidepressants (TCAs) and chlorpromazine, close monitoring is essential and dose reduction may become necessary to avoid toxicity. Chlorpromazine is associated with an established risk of QT prolongation and torsades de pointes (TdP); case reports have included patients receiving therapeutic doses of chlorpromazine. TCAs may cause cardiac effects (e.g., QT prolongation) in some cases. Additive anticholinergic effects, hypotension, and sedation may also occur.
Chlorzoxazone: (Moderate) Concomitant use of chlorzoxazone with tricyclic antidepressants can result in additive CNS depression.
Cholinergic agonists: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Cimetidine: (Moderate) Cimetidine can inhibit the systemic clearance of tricyclic antidepressants that undergo oxidative metabolism, such as clomipramine, resulting in increased plasma levels of the antidepressant. Patients should be monitored for TCA-related side effects and toxicity if cimetidine is added; when possible, choose an alternative H2-blocker for treatment.
Cinacalcet: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with cinacalcet is necessary; a dose reduction of TCA may be necessary. Concurrent use may increase the exposure of TCAs which are CYP2D6 substrates; cinacalcet is a CYP2D6 inhibitor.
Citalopram: (Major) Citalopram causes dose-dependent QT interval prolongation and tricyclic antidepressants are associated with a possible risk of QT prolongation and torsade de pointes (TdP). According to the manufacturer, concurrent use of citalopram with other drugs that prolong the QT interval is not recommended. If concurrent therapy is considered essential, ECG monitoring is recommended. In addition, because of the potential risk and severity of serotonin syndrome, caution should be observed when administering citalopram with other drugs that have serotonergic properties such as tricyclic antidepressants. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Clinicians should also be alert for pharmacokinetic interactions between tricyclic antidepressants (TCAs) and SSRIs. Citalopram is a weak inhibitor of CYP2D6, the isoenzyme responsible for metabolism of many of the tricyclic antidepressants. Coadministration of citalopram and imipramine did not significantly affect the plasma concentrations of either drug. However, the concentration of desipramine, the primary metabolite of imipramine, was increased by 50%. The clinical significance of the elevation in desipramine concentration is unknown. However, symptoms of toxicity, including seizures, have been reported when drugs from these 2 classes were used together. A decreased dosage of the TCA or the avoidance of concomitant SSRI therapy should be considered.
Clemastine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Clobazam: (Moderate) A dosage reduction of CYP2D6 substrates, such tricyclic antidepressants, may be necessary during co-administration of clobazam. Limited in vivo data suggest that clobazam is an inhibitor of CYP2D6. Additive CNS depressant effects are possible when clobazam is administered concurrently with tricyclic antidepressants.
Clonazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Clonidine: (Moderate) Monitor blood pressure and for unusual drowsiness or excess sedation during coadministration of clonidine and tricyclic antidepressants. Concomitant use may result in reduced hypotensive effect of clonidine and additive CNS depression.
Clorazepate: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Clozapine: (Moderate) Concurrent use of clozapine and tricyclic antidepressants should be avoided if possible. Treatment with clozapine has been associated with QT prolongation, torsade de pointes (TdP), cardiac arrest, and sudden death. Tricyclic antidepressants have a possible risk of QT prolongation (particularly with elevated concentrations). The manufacturer of clozapine recommends caution during concurrent use with medications known to cause QT prolongation. Anticholinergic effects may be seen when clozapine is used concomitantly with other drugs known to possess antimuscarinic activity like tricyclic antidepressants. Anticholinergic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive hypotension or sedation is also possible when clozapine is combined with these drugs. Anticholinergic effects are most prominent with tertiary TCAs such as amitriptyline, clomipramine, imipramine, trimipramine, and doxepin.
Cobicistat: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Cocaine: (Moderate) Monitor patients for increased CNS stimulation during coadministration of cocaine and tricyclic antidepressants (TCAs). Concurrent use of cocaine and TCAs may increase the risk for excessive sympathetic CNS activity leading to symptoms such as tachycardia, hypertension, diaphoresis, agitation, cardiac arrythmias, or convulsions.
Codeine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Codeine; Guaifenesin: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Codeine; Guaifenesin; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant promethazine and tricyclic antidepressant use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Codeine; Promethazine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant promethazine and tricyclic antidepressant use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
COMT inhibitors: (Major) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including tricyclic antidepressants, due to the possibility of additive sedation. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment. Patients should be advised to avoid driving or other tasks requiring mental alertness until they know how the combination affects them.
Conjugated Estrogens: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Conjugated Estrogens; Bazedoxifene: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Conjugated Estrogens; Medroxyprogesterone: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Cyclobenzaprine: (Moderate) Monitor for unusual drowsiness, sedation, signs of anticholinergic toxicity, and serotonin syndrome during coadministration of cyclobenzaprine and tricyclic antidepressants. Concomitant use may increase the risk for additive CNS depression, anticholinergic adverse events, and serotonin syndrome. If serotonin syndrome occurs, consider discontinuation of therapy.
Cyproheptadine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Dacomitinib: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with dacomitinib is necessary; a dose reduction of TCA may be necessary. Concurrent use may increase the exposure of TCAs which are CYP2D6 substrates; dacomitinib is a CYP2D6 inhibitor.
Dantrolene: (Moderate) Concomitant use of dantrolene with tricyclic antidepressants can result in additive CNS depression.
Daridorexant: (Moderate) Monitor for excessive sedation and somnolence during coadministration of daridorexant and tricyclic antidepressants. Dosage adjustments of daridorexant and the tricyclic antidepressant may be necessary when administered together because of potentially additive CNS effects. The risk of next-day impairment, including impaired driving, is increased if daridorexant is taken with other CNS depressants.
Darifenacin: (Moderate) The exposure to tricyclic antidepressants (TCAs) may be increased when coadministered with darifenacin. Appropriate monitoring and dose adjustment may be necessary. Darifenacin is a moderate CYP2D6 inhibitor; TCAs are CYP2D6 substrates.
Darunavir; Cobicistat: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Degarelix: (Major) Avoid coadministration of degarelix with clomipramine due to the risk of reduced efficacy of degarelix; QT prolongation may also occur. Clomipramine can cause hyperprolactinemia, which reduces the number of pituitary gonadotropin releasing hormone (GnRH) receptors; degarelix is a GnRH analog. Additionally, androgen deprivation therapy (i.e., degarelix) may prolong the QT/QTc interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may also prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Delavirdine: (Major) Delavirdine inhibits CYP2D6 and may increase concentrations of other drugs metabolized by this enzyme, such as tricyclic antidepressants (TCAs). Monitor the patient for side effects associated with TCAs such as an increase in constipation, urinary difficulty, dizziness, or rarely, fast, irregular heartbeat. A dosage adjustment may be needed for TCAs when given concurrently with delavirdine.
Desflurane: (Minor) Tricyclic antidepressants (TCAs) should be used cautiously and with close monitoring with halogenated anesthetics. Halogenated anesthetics can prolong the QT interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, general anesthetics may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Desloratadine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Desmopressin: (Moderate) Additive hyponatremic effects may be seen in patients treated with desmopressin and drugs associated with SIADH including tricyclic antidepressants. Hyponatremia-induced convulsions have been rarely reported when imipramine and desmopressin are used concomitantly. Use these drugs together with caution, and monitor patients for signs and symptoms of hyponatremia.
Desogestrel; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Desvenlafaxine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering serotonin norepinephrine reuptake inhibitors (SNRIs) with other drugs that have serotonergic properties such as tricyclic antidepressants (TCAs). Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. If serotonin syndrome is suspected, desvenlafaxine and concurrent serotonergic agents should be discontinued. Dosage adjustments of TCAs may be necessary during concurrent use of desvenlafaxine. Although clinical studies have shown that desvenlafaxine does not have a clinically relevant effect on CYP2D6 inhibition at doses of 100 mg/day, the manufacturer recommends that primary substrates of CYP2D6, such as desipramine, doxepin, clomipramine, and imipramine be dosed at the original level when co-administered with desvenlafaxine 100 mg or lower or when desvenlafaxine is discontinued. The dose of these CYP2D6 substrates should be reduced by up to one-half if co-administered with desvenlafaxine 400 mg/day.
Deutetrabenazine: (Moderate) The risk of QT prolongation may be increased with coadministration of deutetrabenazine and tricyclic antidepressants (TCAs). Deutetrabenazine may prolong the QT interval, but the degree of QT prolongation is not clinically significant when deutetrabenazine is administered within the recommended dosage range. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Monitor for excessive sedation and somnolence during coadministration of TCAs and deutetrabenazine. Concurrent use may result in additive CNS depression.
Dexbrompheniramine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Dexchlorpheniramine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dexmethylphenidate: (Moderate) Caution should be observed when coadministering methylphenidate derivatives and tricyclic antidepressants (TCAs). There are postmarketing reports of serotonin syndrome occurring during use of methylphenidate derivatives and other serotonergic medications. Patients receiving this combination should be monitored for the emergence of serotonin syndrome. If serotonin syndrome occurs, all serotonergic agents should be discontinued and appropriate medical management should be implemented.
Dextroamphetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Bupropion: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Use extreme caution when coadministering bupropion with other drugs that lower the seizure threshold, such as tricyclic antidepressants. Use low initial doses of bupropion and increase the dose gradually. Monitor patients for an increase in tricyclic antidepressant-related adverse reactions and signs and symptoms of serotonin syndrome during concomitant use, particularly during treatment initiation and dosage increases; a dose reduction of the tricyclic antidepressant may be necessary. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Tricyclic antidepressants are CYP2D6 substrates and bupropion is a CYP2D6 inhibitor.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Dextromethorphan; Guaifenesin: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Guaifenesin; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Guaifenesin; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Quinidine: (Contraindicated) Quinidine administration is associated with QT prolongation and torsade de pointes (TdP). Quinidine inhibits CYP2D6 and has QT-prolonging actions. Quinidine is contraindicated with other drugs that prolong the QT interval and are metabolized by CYP2D6 as the effects on the QT interval may be increased during concurrent use of these agents. Tricyclic antidepressants are associated with a possible risk of QT prolongation, particularly at high dosages or in overdose, and are substrates for CYP2D6. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Diazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Dicyclomine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and dicyclomine use. Concomitant use may result in additive anticholinergic adverse effects.
Dienogest; Estradiol valerate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Diethylpropion: (Major) Avoid the use of these agents together. Tricyclic antidepressants (TCAs) may potentiate the pressor response to sympathomimetic agents, such as diethylpropion. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience side effects like hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. Patients should be closely monitored if use together is unavoidable.
Difelikefalin: (Moderate) Monitor for dizziness, somnolence, mental status changes, and gait disturbances if concomitant use of difelikefalin with CNS depressants is necessary. Concomitant use may increase the risk for these adverse reactions.
Dimenhydrinate: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of dimenhydrinate and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Diphenhydramine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Diphenhydramine; Ibuprofen: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Diphenhydramine; Naproxen: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Diphenhydramine; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of diphenhydramine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Diphenoxylate; Atropine: (Moderate) Concurrent administration can potentiate the CNS and respiratory depressant effects of diphenoxylate/difenoxin and the CNS depressant effects of the tricyclic antidepressant (TCA). Both TCAs and diphenoxylate/difenoxin may cause constipation. Use caution during coadministration. Cases of severe GI reactions including toxic megacolon and adynamic ileus have been rarely reported. In some cases, a dosage reduction of diphenoxylate or difenoxin might be needed to manage any noted side effects. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Disopyramide: (Major) Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). This pharmacologic property of the TCAs is of concern in patients with significant cardiac histories or treated with selected cardiac agents. Cases of long QT syndrome and torsade de pointes tachycardia have been described with TCA use, but rarely occur when TCAs are used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of TCAs in combination with other QT-prolonging drugs. One study reported the common occurrence of overlapping prescriptions for 2 or more drugs with potential for QT-prolonging effects; antidepressants were involved in nearly 50% of the cases, but there are little data to document safety of the combined therapies. Class IA antiarrhythmics are associated with QT prolongation and torsades de pointes (TdP). The need to coadminister TCAs with any of these therapies should be done with a careful assessment of risk versus benefit; consider alternative therapy to the TCA. In addition to effects on the EKG, disopyramide has significant anticholinergic effects that are additive to those of the TCAs.
Disulfiram: (Moderate) Limited data suggest that the combination of tricyclic antidepressants with disulfiram can produce transient delirium. In addition, disulfiram may inhibit some of the CYP450 isoenzymes involved in tricyclic antidepressant metabolism, although the clinical significance is unknown.
Donepezil: (Moderate) Use donepezil with caution in combination with tricyclic antidepressants as concurrent use may increase the risk of QT prolongation; the efficacy of donepezil may also be reduced. Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Donepezil inhibits acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, and improves the availability of acetylcholine. Tricyclic antidepressants with significant anticholinergic activity, such as amitriptyline, imipramine, doxepin, and clomipramine, are more likely to interfere with the therapeutic effect of donepezil than other tricyclics.
Donepezil; Memantine: (Moderate) Use donepezil with caution in combination with tricyclic antidepressants as concurrent use may increase the risk of QT prolongation; the efficacy of donepezil may also be reduced. Case reports indicate that QT prolongation and torsade de pointes (TdP) can occur during donepezil therapy. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Donepezil inhibits acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, and improves the availability of acetylcholine. Tricyclic antidepressants with significant anticholinergic activity, such as amitriptyline, imipramine, doxepin, and clomipramine, are more likely to interfere with the therapeutic effect of donepezil than other tricyclics.
Dopamine: (Moderate) Monitor blood pressure and carefully adjust doses during concomitant use of dopamine and tricyclic antidepressants due to the risk for hypertension. Concomitant use of tricyclic antidepressants may potentiate the cardiovascular effects of dopamine.
Doxylamine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of doxylamine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Doxylamine; Pyridoxine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of doxylamine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Dronabinol: (Moderate) Use caution if coadministration of dronabinol with tricyclic antidepressants (e.g., amitriptyline, desipramine) is necessary. Concurrent use of dronabinol, THC with tricyclic antidepressants may result in additive drowsiness, hypertension, tachycardia, and possibly cardiotoxicity.
Dronedarone: (Contraindicated) Coadministration of dronedarone and tricyclic antidepressants is contraindicated due to the potential for QT prolongation and torsade de pointes (TdP). Tricyclic antidepressants (TCAs) have pharmacologic properties like the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Dronedarone administration is associated with a dose-related increase in the QTc interval. The increase in QTc is approximately 10 milliseconds at doses of 400 mg twice daily (the FDA-approved dose) and up to 25 milliseconds at doses of 1600 mg twice daily. Although there are no studies examining the effects of dronedarone in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation.
Drospirenone; Estetrol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Drospirenone; Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Drospirenone; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Drospirenone; Ethinyl Estradiol; Levomefolate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Duloxetine: (Moderate) Monitor for an increase in tricyclic antidepressant-related adverse reactions and signs and symptoms of serotonin syndrome if coadministration with duloxetine is necessary, particularly during treatment initiation and dosage increases; a dose reduction of the tricyclic antidepressant may be necessary. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Concurrent use may increase exposure of the tricyclic antidepressant. Tricyclic antidepressants are CYP2D6 substrates and duloxetine is a CYP2D6 inhibitor.
Elagolix; Estradiol; Norethindrone acetate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Elbasvir; Grazoprevir: (Moderate) Administering clomipramine with elbasvir; grazoprevir may result in elevated clomipramine plasma concentrations. Clomipramine is a substrate of CYP3A; grazoprevir is a weak CYP3A inhibitor. If these drugs are used together, closely monitor for signs of adverse events.
Eletriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Eliglustat: (Moderate) Coadminister tricyclic antidepressants (TCAs) and eliglustat cautiously and with close monitoring; there may be an increased risk of QT prolongation and/or antidepressant-associated adverse effects. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, coadministration may result in increased concentrations of the antidepressant. If eliglustat and a TCA are used together, consider reducing the dosage of the TCA and titrating to clinical effect. When available, monitoring antidepressant serum concentrations may be beneficial. Eliglustat is a CYP2D6 inhibitor, and tricyclic antidepressants are CYP2D6 substrates.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Close monitoring for antidepressant response and careful dose titrations of the antidepressant therapy is recommended during coadministration of tricyclic antidepressants (TCAs) and cobicistat. Concurrent use may result in elevated TCA plasma concentrations.
Enasidenib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of enasidenib is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 and CYP2D6 substrate and enasidenib is a strong CYP1A2 and weak CYP2D6 inhibitor.
Entacapone: (Major) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including tricyclic antidepressants, due to the possibility of additive sedation. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment. Patients should be advised to avoid driving or other tasks requiring mental alertness until they know how the combination affects them.
Ephedrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to certain sympathomimetic agents, such as ephedrine or ephedra. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Ephedrine; Guaifenesin: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to certain sympathomimetic agents, such as ephedrine or ephedra. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Epinephrine: (Major) Avoid use of epinephrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the vasopressor effects of epinephrine.
Erythromycin: (Minor) The use of erythromycin with tricyclic antidepressants is rarely problematic. Tricyclic antidepressants may prolong the QT interval, particularly in overdose, and erythromycin has also been reported to have this effect in rare circumstances. Erythromycin is sometimes used to stimulate GI motility, for example, in patients with diabetic gastroparesis. In patients requiring erythromycin to enhance GI motility, some tricyclic antidepressants with substantial antimuscarinic properties may counteract erythromycin's effectiveness.
Escitalopram: (Moderate) Use tricyclic antidepressants (TCAs) and escitalopram together with caution as concurrent use may increase the risk of QT prolongation and serotonin syndrome; a decreased dosage of the TCA or the avoidance of concomitant SSRI therapy should be considered. Elevated concentrations of the tricyclic antidepressant may occur. Symptoms of toxicity, including seizures, have been reported when drugs from these 2 classes were used together. If serotonin syndrome is suspected, discontinue all serotonergic agents. Escitalopram is a moderate inhibitor of CYP2D6 that has been associated with a risk of QT prolongation and torsade de pointes (TdP). CYP2D6 is responsible for metabolism of many of the tricyclic antidepressants. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Esketamine: (Major) Closely monitor patients receiving esketamine and a tricyclic antidepressant for sedation and other CNS depressant effects. Patients who receive a dose of esketamine should not drive or engage in other activities requiring alertness until the next day after a restful sleep.
Eslicarbazepine: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions.
Esomeprazole: (Minor) Esomeprazole may inhibit the CYP2C19 isoenzyme, leading to increased plasma levels of drugs that are substrates for the CYP2C19 isoenzyme, such as clomipramine.
Estazolam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Esterified Estrogens: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Esterified Estrogens; Methyltestosterone: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estradiol; Levonorgestrel: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estradiol; Norethindrone: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estradiol; Norgestimate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estradiol; Progesterone: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estrogens: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Estropipate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Eszopiclone: (Moderate) A reduction in the dose of eszopiclone and concomitantly administered CNS depressants, such as tricyclic antidepressants, should be considered to minimize additive sedative effects. In addition, the risk of next-day psychomotor impairment is increased during co-administration of eszopiclone and other CNS depressants, which may decrease the ability to perform tasks requiring full mental alertness such as driving. Tricyclics with a higher incidence of sedation, such as amitriptyline, imipramine, doxepin, and clomipramine, are more likely to interact with eszopiclone.
Ethanol: (Major) Advise patients to avoid alcohol consumption while taking CNS depressants such as tricyclic antidepressants (TCAs). TCAs may exaggerate the CNS depressant response to alcohol, leading to an increase in sedation or psychomotor impairment. In some studies, alcohol has increased the unbound form of the TCA in the blood, which might be related to exaggerated clinical effect.
Ethinyl Estradiol; Norelgestromin: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Ethinyl Estradiol; Norethindrone Acetate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Ethinyl Estradiol; Norgestrel: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Ethiodized Oil: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Ethosuximide: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase drowsiness and CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Ethotoin: (Moderate) Tricyclic antidepressants (TCA), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently. In addition, hydantoins may increase TCA metabolism.
Ethynodiol Diacetate; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Etomidate: (Moderate) General anesthetics like etomidate may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Etonogestrel; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Everolimus: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if coadministration with everolimus is necessary. Clomipramine is a CYP2D6 substrate and everolimus is a CYP2D6 inhibitor; concomitant use may increase plasma concentrations of clomipramine.
Fedratinib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if coadministration with fedratinib is necessary; a dose reduction of clomipramine may be necessary. Clomipramine is a CYP2D6 and CYP2C19 substrate and fedratinib is a moderate CYP2D6 and CYP2C19 inhibitor.
Felbamate: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Fenfluramine: (Moderate) Use fenfluramine and tricyclic antidepressants with caution due to an increased risk of serotonin syndrome and additive CNS depression. Monitor for excessive sedation, somnolence, and serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Fenofibric Acid: (Minor) At therapeutic concentrations, fenofibric acid is a weak inhibitor of CYP2C19. Concomitant use of fenofibric acid with CYP2C19 substrates, such as clomipramine, has not been formally studied. Fenofibric acid may theoretically increase plasma concentrations of CYP2C19 substrates and could lead to toxicity for drugs that have a narrow therapeutic range. Monitor the therapeutic effect of clomipramine during coadministration with fenofibric acid.
Fentanyl: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Fexinidazole: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of fexinidazole is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and fexinidazole is a CYP1A2 inhibitor.
Fexofenadine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Flavoxate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and flavoxate use. Concomitant use may result in additive anticholinergic adverse effects.
Fluconazole: (Minor) Fluconazole has been associated with QT prolongation and rare cases of torsades de pointes (TdP). Tricyclic antidepressants have been associated with a possible risk of QT prolongation. Fluconazole should be administered together with TCAs with caution.
Flumazenil: (Major) Particular caution is necessary when using flumazenil in cases of mixed drug overdosage since the toxic effects (such as convulsions and cardiac dysrhythmias) of other drugs taken in overdose (especially tricyclic antidepressants) may emerge with the reversal of the benzodiazepine effect by flumazenil. The reversal of benzodiazepine effects may be associated with the onset of seizures in certain high-risk populations; concurrent cyclic antidepressant poisoning is a risk factor for seizures. Flumazenil is not recommended in cases of serious cyclic antidepressant poisoning, as manifested by motor abnormalities (twitching, rigidity, focal seizure), dysrhythmia (wide QRS, ventricular dysrhythmia, heart block), anticholinergic signs (mydriasis, dry mucosa, hypoperistalsis), and cardiovascular collapse at presentation. In such cases flumazenil should be withheld and the patient should be allowed to remain sedated (with ventilatory and circulatory support as needed) until the signs of antidepressant toxicity have subsided. Treatment with flumazenil has no known benefit to the seriously ill mixed-overdose patient other than reversing sedation and should not be used in cases where seizures (from any cause) are likely.
Fluoxetine: (Moderate) Coadministration of fluoxetine and clomipramine may increase the risk for QT prolongation, torsade de pointes (TdP), and serotonin syndrome. If serotonin syndrome is suspected, discontinue fluoxetine and concurrent serotonergic agents and initiate appropriate medical treatment. QT prolongation and TdP have been reported in patients treated with fluoxetine. Tricyclics, particularly at elevated concentrations, are associated with a possible risk of QT prolongation and TdP.
Fluphenazine: (Moderate) When prescribing tricyclic antidepressants (TCAs) to patients already receiving phenothiazine therapy, close monitoring is essential and dose reduction may become necessary to avoid toxicity. Lower doses than usually prescribed for either the phenothiazine or the TCA may be required. TCAs may impair metabolism via the hepatic isoenzyme CYP2D6 at therapeutic doses and may result in increased serum phenothiazine concentrations, leading to side effects. Depending on the specific agent, additive anticholinergic effects may also be seen; clinicians should note that antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive drowsiness or other additive CNS effects may also occur. TCAs may also cause additive cardiac effects (e.g., QT prolongation) in some cases.
Flurazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Fluvoxamine: (Major) Concomitant use of fluvoxamine and tricyclic antidepressants (TCAs) such as clomipramine may increase the risk of serotonin syndrome, QT prolongation, and torsade de pointes (TdP). Tricyclics share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with high dose therapy (elevated serum concentrations). QT prolongation and TdP have been reported during postmarketing use of fluvoxamine. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. In addition, clomipramine is a primary substrate of CYP2D6 with a lesser contribution by CYP1A2. Fluvoxamine is a potent CYP1A2 inhibitor and a mild CYP2D6 inhibitor. At least one case report exists of a death thought to be due to impaired clearance of the TCA amitriptyline by fluoxetine. Patients receiving clomipramine should be monitored closely for toxicity if fluvoxamine is added.
Fosphenytoin: (Moderate) Tricyclic antidepressants (TCA), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently. In addition, hydantoins may increase TCA metabolism.
Frovatriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Gabapentin: (Major) Initiate gabapentin at the lowest recommended dose and monitor patients for symptoms of sedation and somnolence during coadministration of gabapentin and tricyclic antidepressants. Concomitant use of gabapentin with tricyclic antidepressants may cause additive CNS depression. Educate patients about the risks and symptoms of excessive CNS depression.
Galantamine: (Moderate) The therapeutic benefits of galantamine may be diminished when coadministered with drugs known to exhibit anticholinergic properties including tricyclic antidepressants (TCAs). When concurrent use cannot be avoided, monitor the patient for reduced galantamine efficacy, and consider use of secondary TCAs (e.g., desipramine, nortriptyline), which generally have less potent anticholinergic effects than tertiary TCAs (e.g., amitriptyline, clomipramine).
Givosiran: (Major) Avoid concomitant use of givosiran and clomipramine due to the risk of increased clomipramine-related adverse reactions. If use is necessary, consider decreasing the clomipramine dose. Clomipramine is a CYP2D6 substrate. Givosiran may moderately reduce hepatic CYP2D6 enzyme activity because of its pharmacological effects on the hepatic heme biosynthesis pathway.
Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Glycopyrrolate; Formoterol: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Goserelin: (Major) Avoid coadministration of goserelin with clomipramine due to the risk of reduced efficacy of goserelin; QT prolongation may also occur. Chlorpromazine can cause hyperprolactinemia, which reduces the number of pituitary gonadotropin releasing hormone (GnRH) receptors; goserelin is a GnRH analog. Additionally, Tricyclic antidepressants (e.g., clomipramine) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Androgen deprivation therapy (i.e., goserelin) may also prolong the QT/QTc interval.
Granisetron: (Moderate) Use granisetron with caution in combination with tricyclic antidepressants due to increased risk for QT prolongation, torsade de pointes (TdP), and serotonin syndrome. Discontinue all serotonergic agents and initiate supportive therapy if serotonin syndrome is suspected. Granisetron has been associated with QT prolongation. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Guaifenesin; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Guaifenesin; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Guanfacine: (Major) Tricyclic antidepressants (TCAs) can inhibit the hypotensive effects of guanfacine, causing an increase in blood pressure if given concomitantly. Consider alternatives to TCAs in patients established on guanfacine therapy for hypertension when possible; it is not clear the effect the combination may have when used in patients treated with guanfacine for attention-deficit, but other options to TCAs should be considered. Increased dosages of guanfacine may be required to control blood pressure in patients who are receiving TCAs concurrently. In addition, concurrent TCAs may enhance the potential for serious rebound hypertension following guanfacine discontinuation, regardless of the indication for treatment. If guanfacine therapy is withdrawn, guanfacine should be tapered gradually and the patient should be monitored for potential hypertension.
Guanidine: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Guselkumab: (Moderate) Clinically relevant drug interactions may occur when guselkumab is administered with sensitive substrates of CYP2D6, such as tricyclic antidepressants (TCA). Monitor TCA concentrations if guselkumab is initiated or discontinued; the TCA dose may need to be adjusted. During chronic inflammation, increased levels of certain cytokines can alter the formation of CYP450 enzymes. Thus, the formation of CYP2D6 could be normalized during guselkumab administration.
Halogenated Anesthetics: (Minor) Tricyclic antidepressants (TCAs) should be used cautiously and with close monitoring with halogenated anesthetics. Halogenated anesthetics can prolong the QT interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, general anesthetics may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Haloperidol: (Moderate) Haloperidol can potentiate the actions of other CNS depressants such as tricyclic antidepressants (TCAs). Caution should be exercised with simultaneous use of these agents due to potential excessive CNS effects. Limited data suggest that haloperidol may inhibit the metabolism of some tricyclic antidepressants, however, the clinical significance of this interaction is uncertain. Haloperidol is an inhibitor of hepatic CYP2D6, and coadministration with many TCAs (which are CYP2D6 substrates) may lead to elevated TCA serum concentrations, potentiating toxicity. Haloperidol has also been associated with a possible risk for QT prolongation and/or torsades de pointes, particularly when excessive doses are used or in overdose. Haloperidol should be used cautiously with other agents that may have this effect (e.g., tricyclic antidepressants).
Homatropine; Hydrocodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and homatropine use. Concomitant use may result in additive anticholinergic adverse effects.
Hydantoins: (Moderate) Tricyclic antidepressants (TCA), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently. In addition, hydantoins may increase TCA metabolism.
Hydrocodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Hydrocodone; Ibuprofen: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Hydromorphone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydroxyzine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of hydroxyzine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Hyoscyamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Contraindicated) According to the manufacturer of clomipramine, treatment initiation with clomipramine is contraindicated in patients currently receiving intravenous methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than clomipramine (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving clomipramine and requiring urgent treatment with intravenous methylene blue, clomipramine should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits of methylene blue outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Clomipramine may be re-initiated 24 hours after the last dose of methylene blue. Results from an in vitro study indicate that methylene blue is a potent, reversible inhibitor of the monoamine oxidase type A enzyme (MAO-A). MAO-A is responsible for the metabolism of serotonin; therefore, concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Clomipramine, a tricyclic antidepressant, is the most selective and potent inhibitor of serotonin within its class. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. One case report describes a patient receiving clomipramine who experienced jerky movements in all four limbs, as well as confusion and agitation after intravenous administration of methylene blue, with a return to her pre-operative state by day 4. Although the authors attribute this reaction to methylene blue toxicity, they did not exclude the possibility of a drug interaction based upon previous reports of an interaction between injectable methylene blue and selective serotonin reuptake inhibitors (SSRIs). Published interaction reports between intravenousely administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Signs and symptoms of serotonin syndrome include fever, diaphoresis, shivering, myoclonus, tremor, tachycardia, diarrhea, nausea, headache, incoordination, mental status changes (e.g., agitation, confusion), hyperreflexia, seizures, and coma. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Ibuprofen; Oxycodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Ibuprofen; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Idelalisib: (Major) Avoid concomitant use of idelalisib, a strong CYP3A inhibitor, with clomipramine, a CYP3A substrate, as clomipramine toxicities may be significantly increased. The AUC of a sensitive CYP3A substrate was increased 5.4-fold when coadministered with idelalisib.
Imatinib: (Major) Imatinib is a potent inhibitor of CYP2D6 and may increase concentrations of other drugs metabolized by this enzyme, such as the tricyclic antidepressants (TCAs). An increase in serum concentrations may increase the risk for TCA-related side effects, such as constipation, dizziness, difficulty with urination, xerostomia, fast or irregular heartbeat, and very rarely, QT prolongation.
Indacaterol; Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Iobenguane I 123: (Major) Discontinue medications that decrease norepinephrine uptake, such as tricyclic antidepressants, for at least 5 biological half-lives prior to iobenguane I 123 administration. Consider medication tapering or additional supportive therapy as appropriate to minimize the risk for precipitating tricyclic antidepressant withdrawal symptoms. Medications that decrease the uptake of norepinephrine can cause false negative imaging results. Increasing the dose of iobenguane I 123 will not overcome any potential uptake limiting effect of this medication.
Iobenguane I 131: (Major) Discontinue tricyclic antidepressants for at least 5 half-lives before the administration of the dosimetry dose or a therapeutic dose of iobenguane I-131. Do not restart tricyclic antidepressants until at least 7 days after each iobenguane I-131 dose. Drugs that reduce catecholamine uptake or deplete catecholamine stores, such as tricyclic antidepressants, may interfere with iobenguane I-131 uptake into cells and interfere with dosimetry calculations resulting in altered iobenguane I-131 efficacy.
Iodixanol: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iohexol: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iomeprol: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iopamidol: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iopromide: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Ioversol: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Isavuconazonium: (Moderate) Concomitant use of isavuconazonium with clomipramine may result in increased serum concentrations of clomipramine. Clomipramine is a substrate of the hepatic isoenzyme CYP3A4; isavuconazole, the active moiety of isavuconazonium, is a moderate inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are used together.
Isocarboxazid: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders are contraindicated for use with tricyclic antidepressants (TCAs) or within 14 days of discontinuing treatment with a TCA. Conversely, TCAs should not be initiated within 14 days of stopping an MAOI. Monitor for serotonin-related side effects during therapy transitions.
Isoflurane: (Minor) Tricyclic antidepressants (TCAs) should be used cautiously and with close monitoring with halogenated anesthetics. Halogenated anesthetics can prolong the QT interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, general anesthetics may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Isoniazid, INH: (Major) Due to the risk of serotonin syndrome, concurrent use of tricyclic antidepressants and medications with MAO-like activity, such as isoniazid, INH, should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, clomipramine and concurrent serotonergic agents should be discontinued.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Due to the risk of serotonin syndrome, concurrent use of tricyclic antidepressants and medications with MAO-like activity, such as isoniazid, INH, should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, clomipramine and concurrent serotonergic agents should be discontinued. (Moderate) It may be necessary to adjust the dosage of tricyclic antidepressants if given concurrently with rifampin. Rifampin may induce the metabolism of tricyclic antidepressants; coadministration may result in decreased tricyclic antidepressant plasma concentrations.
Isoniazid, INH; Rifampin: (Major) Due to the risk of serotonin syndrome, concurrent use of tricyclic antidepressants and medications with MAO-like activity, such as isoniazid, INH, should be avoided if possible. Isoniazid is chemically related to iproniazid, a drug that was known to possess MAO inhibiting activity. Although isoniazid does not inhibit mitochondrial MAO, it does appear to inhibit plasma MAO and may possess enough MAO inhibiting activity to produce clinical symptoms consistent with serotonergic excess. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, clomipramine and concurrent serotonergic agents should be discontinued. (Moderate) It may be necessary to adjust the dosage of tricyclic antidepressants if given concurrently with rifampin. Rifampin may induce the metabolism of tricyclic antidepressants; coadministration may result in decreased tricyclic antidepressant plasma concentrations.
Isoproterenol: (Moderate) Monitor hemodynamic parameters during concomitant isoproterenol and tricyclic antidepressant use; dosage adjustments may be necessary. Tricyclic antidepressants may potentiate the effects of isoproterenol.
Isosulfan Blue: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Itraconazole: (Minor) Use itraconazole with caution in combination with tricyclic antidepressants as concurrent use may increase the risk of QT prolongation. Itraconazole has been associated with prolongation of the QT interval. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). CYP2C19 and CYP3A4 may be partially involved in the metabolism of TCAs; itraconazole may increase TCA concentrations via inhibition of CYP3A4. In at least one case, an increased incidence of TCA-related side effects, such as dizziness and syncope has occurred in combination with an azole antifungal. In another case, QT-prolongation and torsades de pointes occurred.
Ketamine: (Moderate) General anesthetics, including ketamine, may generally produce additive CNS depression when used in patients taking tricyclic antidepressants (TCAs). Specific interactions between ketamine and TCAs are not certain.
Labetalol: (Moderate) Monitor for an increase in the incidence and severity of tremor and tricyclic antidepressant (TCA)-related adverse effects during concomitant use of labetalol and TCAs. An increase in the incidence of tremor has been observed during concomitant use of labetalol with tricyclic antidepressants; the mechanism of interaction is unknown. Concomitant use may also increase TCA exposure; TCAs are CYP2D6 substrates and labetalol is a weak CYP2D6 inhibitor.
Lacosamide: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions.
Lamotrigine: (Moderate) Consider ECG monitoring before and during concomitant use of lamotrigine with other sodium channel blockers known to impair atrioventricular and/or intraventricular cardiac conduction, such as tricyclic antidepressants. Concomitant use of tricyclic antidepressants with lamotrigine may increase the risk of proarrhythmia, especially in patients with clinically important structural or functional heart disease. In vitro testing showed that lamotrigine exhibits class IB antiarrhythmic activity at therapeutically relevant concentrations.
Lasmiditan: (Moderate) Monitor for excessive sedation, somnolence, and serotonin syndrome during coadministration of lasmiditan and tricyclic antidepressants. Inform patients taking this combination of the risks and symptoms of excessive CNS depression and serotonin syndrome, particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Lemborexant: (Moderate) Monitor for excessive sedation and somnolence during coadministration of lemborexant and tricyclic antidepressants. Dosage adjustments of lemborexant and the tricyclic antidepressant may be necessary when administered together because of potentially additive CNS effects. The risk of next-day impairment, including impaired driving, is increased if lemborexant is taken with other CNS depressants.
Leniolisib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of leniolisib is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and leniolisib is a CYP1A2 inhibitor.
Levocetirizine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and tricyclic antidepressants. Concomitant use may result in additive CNS depression or anticholinergic effects.
Levodopa: (Moderate) Monitor blood pressure and for symptoms of dyskinesia during concomitant levodopa and tricyclic antidepressant use. There have been rare reports of adverse reactions, including hypertension and dyskinesia, resulting from the concomitant use.
Levomilnacipran: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering serotonin norepinephrine reuptake inhibitors (SNRIs) with other drugs that have serotonergic properties such as tricyclic antidepressants. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. If serotonin syndrome is suspected, the tricyclic antidepressant and concurrent serotonergic agents should be discontinued.
Levonorgestrel; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Levonorgestrel; Ethinyl Estradiol; Ferrous Fumarate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Levorphanol: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Reduce the initial dose of levorphanol by approximately 50% or more. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Levothyroxine: (Minor) Thyroid hormones may increase receptor sensitivity and enhance the effects of tricyclic antidepressants. Although this drug combination appears to be safe, be aware of the possibility of exaggerated cardiovascular side effects such as arrhythmias and CNS stimulation.
Levothyroxine; Liothyronine (Porcine): (Minor) Thyroid hormones may increase receptor sensitivity and enhance the effects of tricyclic antidepressants. Although this drug combination appears to be safe, be aware of the possibility of exaggerated cardiovascular side effects such as arrhythmias and CNS stimulation.
Levothyroxine; Liothyronine (Synthetic): (Minor) Thyroid hormones may increase receptor sensitivity and enhance the effects of tricyclic antidepressants. Although this drug combination appears to be safe, be aware of the possibility of exaggerated cardiovascular side effects such as arrhythmias and CNS stimulation.
Lidocaine: (Major) If epinephrine is added to lidocaine for the purpose of infiltration and nerve block or spinal anesthesia, receipt of the product to a patient taking tricyclic antidepressants (TCA) may lead to severe, prolonged hypertension. In general, concurrent use of a local anesthetic solution containing epinephrine and a TCA should be avoided. If coadministration is necessary, careful patient monitoring is essential.
Lidocaine; Epinephrine: (Major) Avoid use of epinephrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the vasopressor effects of epinephrine. (Major) If epinephrine is added to lidocaine for the purpose of infiltration and nerve block or spinal anesthesia, receipt of the product to a patient taking tricyclic antidepressants (TCA) may lead to severe, prolonged hypertension. In general, concurrent use of a local anesthetic solution containing epinephrine and a TCA should be avoided. If coadministration is necessary, careful patient monitoring is essential.
Lidocaine; Prilocaine: (Major) If epinephrine is added to lidocaine for the purpose of infiltration and nerve block or spinal anesthesia, receipt of the product to a patient taking tricyclic antidepressants (TCA) may lead to severe, prolonged hypertension. In general, concurrent use of a local anesthetic solution containing epinephrine and a TCA should be avoided. If coadministration is necessary, careful patient monitoring is essential. (Major) Use prilocaine and tricyclic antidepressants together with caution. If epinephrine is added to prilocaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. Administration of a phenothiazine or a butyrophenone may reduce or reverse the pressor effect of epinephrine.
Linezolid: (Contraindicated) According to the manufacturer of clomipramine, treatment initiation with clomipramine is contraindicated in patients currently receiving linezolid due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than clomipramine (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving clomipramine and requiring urgent treatment with linezolid, clomipramine should be discontinued immediately and linezolid therapy initiated only if acceptable alternatives are not available and the potential benefits of linezolid outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of linezolid, whichever comes first. Clomipramine may be re-initiated 24 hours after the last dose of linezolid. Linezolid is an antibiotic that is also a non-selective monoamine oxidase (MAO) inhibitor. Since monoamine oxidase type A deaminates serotonin, administration of a non-selective MAO inhibitor concurrently with clomipramine can lead to serious reactions including serotonin syndrome or neuroleptic malignant syndrome-like reactions. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
Liothyronine: (Minor) Thyroid hormones may increase receptor sensitivity and enhance the effects of tricyclic antidepressants. Although this drug combination appears to be safe, be aware of the possibility of exaggerated cardiovascular side effects such as arrhythmias and CNS stimulation.
Lisdexamfetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Lithium: (Moderate) Monitor for serotonin syndrome, particularly during lithium initiation, during concomitant tricyclic antidepressant use. If serotonin syndrome occurs, consider discontinuation of lithium and/or the tricyclic antidepressant.
Lofexidine: (Moderate) Monitor for excessive hypotension and sedation during coadministration of lofexidine and tricyclic antidepressants. Lofexidine can potentiate the effects of CNS depressants. Additionally, monitor ECG during coadministration due to the potential risk for additive QT prolongation. Lofexidine prolongs the QT interval. In addition, there are postmarketing reports of torsade de pointes. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Lopinavir; Ritonavir: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with ritonavir is necessary; a dose reduction of the TCA may be necessary. Concurrent use may increase exposure of the TCA. TCAs are CYP2D6 substrates and ritonavir is a CYP2D6 inhibitor.
Loratadine; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Lorazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Lorcaserin: (Moderate) Based on the mechanism of action of lorcaserin and the theoretical potential for serotonin syndrome, use with extreme caution in combination with other drugs that may affect the serotonergic neurotransmitter systems, including, tricyclic antidepressants. Patients receiving this combination should be monitored for the emergence of serotonin syndrome or Neuroleptic Malignant Syndrome (NMS) like signs and symptoms.
Loxapine: (Moderate) Use caution when combining tricyclic antidepressants (TCAs) with loxapine, which both exhibit anticholinergic activity and may cause CNS effects. Some TCAs may be more likely to cause side effects than others. Because secondary amines, such as desipramine, are generally less likely than tertiary amines (e.g., amitriptyline) to cause sedation, orthostatic hypotension, and anticholinergic effects, TCAs such as desipramine may be preferred for use with antipsychotics.
Luliconazole: (Moderate) Theoretically, luliconazole may increase the side effects of clomipramine, which is a CYP2C19 and CYP3A4 substrate. Monitor patients for adverse effects of clomipramine, such as QT prolongation, CNS effects, or antimuscarinic effects. In vitro, therapeutic doses of luliconazole inhibit the activity of CYP2C19 and CYP3A4 and small systemic concentrations may be noted with topical application, particularly when applied to patients with moderate to severe tinea cruris. No in vivo drug interaction trials were conducted prior to the approval of luliconazole.
Lumacaftor; Ivacaftor: (Moderate) Lumacaftor; ivacaftor may reduce the efficacy of clomipramine by decreasing its systemic exposure. If used together, monitor patients closely for clomipramine efficacy; a clomipramine dosage adjustment may be required to obtain the desired therapeutic effect. Do not exceed the recommended maximum dosage. Clomipramine is primarily metabolized by CYP3A4 (and CYP2D6) and is also a substrate of CYP2C19. Lumacaftor is a strong CYP3A inducer; in vitro data also suggest that lumacaftor; ivacaftor may also induce CYP2C19.
Lumacaftor; Ivacaftor: (Moderate) Lumacaftor; ivacaftor may reduce the efficacy of clomipramine by decreasing its systemic exposure. If used together, monitor patients closely for clomipramine efficacy; a clomipramine dosage adjustment may be required to obtain the desired therapeutic effect. Do not exceed the recommended maximum dosage. Clomipramine is primarily metabolized by CYP3A4 (and CYP2D6) and is also a substrate of CYP2C19. Lumacaftor is a strong CYP3A inducer; in vitro data also suggest that lumacaftor; ivacaftor may also induce CYP2C19.
Lumateperone: (Moderate) Monitor for excessive sedation and somnolence during coadministration of lumateperone and tricyclic antidepressants. Concurrent use may result in additive CNS depression.
Maprotiline: (Contraindicated) The use of maprotiline with tricyclic antidepressants (TCAs) is not generally recommended, due to the duplicative nature of therapy and the risk for side effects. Additive cardiac effects (e.g., prolonged QT interval), CNS effects, or antimuscarinic effects may occur. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Meclizine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Melatonin: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of melatonin and tricyclic antidepressants due to the risk for additive CNS depression.
Meperidine: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Mepivacaine: (Major) Use mepivacaine and tricyclic antidepressants together with caution. If epinephrine is added to mepivacaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. Administration of a phenothiazine or a butyrophenone may reduce or reverse the pressor effect of epinephrine.
Meprobamate: (Moderate) The CNS-depressant effects of meprobamate can be potentiated with concomitant administration of other drugs known to cause CNS depression, including tricyclic antidepressants. If used together, a reduction in the dose of one or both drugs may be needed.
Metaxalone: (Moderate) Coadministration of tricyclic antidepressants (TCAs) with metaxalone may result in additive CNS-depressant effects, such as sedation, and may increase the risk for serotonin syndrome. Use with caution and monitor for the emergence of excessive sedation or serotonin syndrome. If serotonin syndrome is suspected, serotonergic agents should be discontinued and appropriate medical treatment instituted.
Methadone: (Major) Concomitant use of methadone with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of methadone with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. The need to coadminister methadone with drugs known to prolong the QT interval should be done with extreme caution and a careful assessment of treatment risks vs. benefits. Methadone is associated with an increased risk for QT prolongation and torsade de pointes (TdP), especially at higher doses (more than 200 mg/day but averaging approximately 400 mg/day in adult patients). Most cases involve patients being treated for pain with large, multiple daily doses of methadone, although cases have been reported in patients receiving doses commonly used for maintenance treatment of opioid addiction. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose therapy (elevated serum concentrations). Monitor patients closely for cardiac conduction changes. Also monitor patients for the emergence of serotonin syndrome and for signs of urinary retention or reduced gastric motility. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. The concomitant use of opioids with anticholinergic drugs may increase risk of urinary retention or severe constipation, which may lead to paralytic ileus.
Methamphetamine: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Contraindicated) According to the manufacturer of clomipramine, treatment initiation with clomipramine is contraindicated in patients currently receiving intravenous methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than clomipramine (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving clomipramine and requiring urgent treatment with intravenous methylene blue, clomipramine should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits of methylene blue outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Clomipramine may be re-initiated 24 hours after the last dose of methylene blue. Results from an in vitro study indicate that methylene blue is a potent, reversible inhibitor of the monoamine oxidase type A enzyme (MAO-A). MAO-A is responsible for the metabolism of serotonin; therefore, concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Clomipramine, a tricyclic antidepressant, is the most selective and potent inhibitor of serotonin within its class. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. One case report describes a patient receiving clomipramine who experienced jerky movements in all four limbs, as well as confusion and agitation after intravenous administration of methylene blue, with a return to her pre-operative state by day 4. Although the authors attribute this reaction to methylene blue toxicity, they did not exclude the possibility of a drug interaction based upon previous reports of an interaction between injectable methylene blue and selective serotonin reuptake inhibitors (SSRIs). Published interaction reports between intravenousely administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Signs and symptoms of serotonin syndrome include fever, diaphoresis, shivering, myoclonus, tremor, tachycardia, diarrhea, nausea, headache, incoordination, mental status changes (e.g., agitation, confusion), hyperreflexia, seizures, and coma. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Methocarbamol: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of methocarbamol and tricyclic antidepressants due to the risk for additive CNS depression.
Methohexital: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Methscopolamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and methscopolamine use. Concomitant use may result in additive anticholinergic adverse effects.
Methsuximide: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Methyldopa: (Moderate) Many references caution against the combined use of tricyclic antidepressants (TCAs) and methyldopa. Although reports exist of loss of blood pressure control when TCAs are added to methyldopa, the interaction is not well documented. Nevertheless, if use of these drugs together is not avoidable, monitor the patient's blood pressure for the desired response.
Methylene Blue: (Contraindicated) According to the manufacturer of clomipramine, treatment initiation with clomipramine is contraindicated in patients currently receiving intravenous methylene blue due to an increased risk of serotonin syndrome. If urgent psychiatric treatment is required, interventions other than clomipramine (e.g., alternative medication, hospitalization) should be considered. Conversely, in patients receiving clomipramine and requiring urgent treatment with intravenous methylene blue, clomipramine should be discontinued immediately and methylene blue therapy initiated only if acceptable alternatives are not available and the potential benefits of methylene blue outweigh the risks. The patient should be monitored for serotonin syndrome for two weeks or until 24 hours after the last dose of methylene blue, whichever comes first. Clomipramine may be re-initiated 24 hours after the last dose of methylene blue. Results from an in vitro study indicate that methylene blue is a potent, reversible inhibitor of the monoamine oxidase type A enzyme (MAO-A). MAO-A is responsible for the metabolism of serotonin; therefore, concurrent use of an MAO-A inhibitor with a serotonergic agent may result in a clinically significant interaction. Clomipramine, a tricyclic antidepressant, is the most selective and potent inhibitor of serotonin within its class. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. One case report describes a patient receiving clomipramine who experienced jerky movements in all four limbs, as well as confusion and agitation after intravenous administration of methylene blue, with a return to her pre-operative state by day 4. Although the authors attribute this reaction to methylene blue toxicity, they did not exclude the possibility of a drug interaction based upon previous reports of an interaction between injectable methylene blue and selective serotonin reuptake inhibitors (SSRIs). Published interaction reports between intravenousely administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. Signs and symptoms of serotonin syndrome include fever, diaphoresis, shivering, myoclonus, tremor, tachycardia, diarrhea, nausea, headache, incoordination, mental status changes (e.g., agitation, confusion), hyperreflexia, seizures, and coma.
Methylphenidate Derivatives: (Moderate) Caution should be observed when coadministering methylphenidate derivatives and tricyclic antidepressants (TCAs). There are postmarketing reports of serotonin syndrome occurring during use of methylphenidate derivatives and other serotonergic medications. Patients receiving this combination should be monitored for the emergence of serotonin syndrome. If serotonin syndrome occurs, all serotonergic agents should be discontinued and appropriate medical management should be implemented.
Methylphenidate: (Moderate) Caution should be observed when coadministering methylphenidate derivatives and tricyclic antidepressants (TCAs). There are postmarketing reports of serotonin syndrome occurring during use of methylphenidate derivatives and other serotonergic medications. Patients receiving this combination should be monitored for the emergence of serotonin syndrome. If serotonin syndrome occurs, all serotonergic agents should be discontinued and appropriate medical management should be implemented.
Metyrapone: (Moderate) Metyrapone may cause dizziness and/or drowsiness. Other drugs that may also cause drowsiness, such as tricyclic antidepressants, should be used with caution. Additive drowsiness and/or dizziness is possible.
Metyrosine: (Moderate) The concomitant administration of metyrosine with sedating H1-blockers can result in additive sedative effects.
Midazolam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Milnacipran: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering serotonin norepinephrine reuptake inhibitors (SNRIs) with other drugs that have serotonergic properties such as tricyclic antidepressants. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, the tricyclic antidepressant and concurrent serotonergic agents should be discontinued.
Minocycline: (Minor) Injectable minocycline contains magnesium sulfate heptahydrate. Because of the CNS-depressant effects of magnesium sulfate, additive central-depressant effects can occur following concurrent administration with CNS depressants such as antidepressants. Caution should be exercised when using these agents concurrently.
Mirabegron: (Moderate) Mirabegron is a moderate CYP2D6 inhibitor. Exposure of tricyclic antidepressants (TCAs), which are CYP2D6 substrates, may be increased when co-administered with mirabegron. In drug interaction studies, mirabegron increased the Cmax of desipramine by 79% and desipramine AUC by 241% after multiple dose administration of 100 mg mirabegron once daily for 18 days and a single dose of 50 mg desipramine before and concomitantly with mirabegron. It is difficult to predict the magnitude of the interaction with each TCA due to differences in the role of CYP2D6 in the metabolism of these drugs. Therefore, appropriate monitoring and dose adjustment may be necessary.
Mirtazapine: (Moderate) Monitor for unusual drowsiness, sedation, and serotonin syndrome during coadministration due to the risk for additive CNS depression and serotonin syndrome. If serotonin syndrome occurs, consider discontinuation of therapy.
Mitotane: (Major) Use caution if mitotane and clomipramine are used concomitantly, and monitor for decreased efficacy of clomipramine and a possible change in dosage requirements. Mitotane is a strong CYP3A4 inducer and clomipramine is a CYP3A4 substrate; coadministration may result in decreased plasma concentrations of clomipramine. Additionally, mitotane can cause sedation, lethargy, vertigo, and other CNS adverse reactions; additive CNS effects may occur initially when mitotane is given concurrently with clomipramine.
Modafinil: (Moderate) Modafinil inhibits CYP2C19 at pharmacologically relevant concentrations. In patients deficient in the CYP2D6 enzyme (poor metabolizers, 7% to 10% of the Caucasian population), the metabolism of certain tricyclics (i.e., clomipramine, desipramine, doxepin, imipramine) may be largely dependent on CYP2C19. One case of a narcoleptic patient is available in which the patient experienced increased side effects and increased serum levels of clomipramine and its active metabolite, desmethylclomipramine, during modafinil treatment. Because tricyclic antidepressants may be given to the narcoleptic patient for the treatment of cataplexy, the health care professional should be aware of the potential for interactions with modafinil. Patients on tricyclic antidepressants may require antidepressant dose reductions.
Molindone: (Moderate) Antipsychotics are associated with anticholinergic effects; therefore, additive effects may be seen during concurrent use of molindone and other drugs having anticholinergic activity such as tricyclic antidepressants. Clinicians should note that antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive drowsiness or other CNS effects may also occur.
Monoamine oxidase inhibitors: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders are contraindicated for use with tricyclic antidepressants (TCAs) or within 14 days of discontinuing treatment with a TCA. Conversely, TCAs should not be initiated within 14 days of stopping an MAOI. Monitor for serotonin-related side effects during therapy transitions.
Morphine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. For extended-release morphine tablets (MS Contin and Morphabond), start with 15 mg every 12 hours. Morphine; naltrexone should be initiated at one-third to one-half the recommended starting dosage. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Morphine; Naltrexone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. For extended-release morphine tablets (MS Contin and Morphabond), start with 15 mg every 12 hours. Morphine; naltrexone should be initiated at one-third to one-half the recommended starting dosage. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Nabilone: (Moderate) Nabilone should be combined cautiously with tricyclic antidepressants. Tachycardia, hypertension, drowsiness or other CNS effects may occur.
Nalbuphine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Naproxen; Esomeprazole: (Minor) Esomeprazole may inhibit the CYP2C19 isoenzyme, leading to increased plasma levels of drugs that are substrates for the CYP2C19 isoenzyme, such as clomipramine.
Naproxen; Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Naratriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Nefazodone: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering tricyclic antidepressants (TCAs) with other drugs that have serotonergic properties such as nefazodone. Both nefazodone and TCAs inhibit the central reuptake of serotonin. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Cases of serotonin syndrome or serotonin-related adverse events have been observed during concurrent use of serotonergic antidepressants and nefazodone. If serotonin syndrome is suspected, tricyclic antidepressants and concurrent serotonergic agents should be discontinued.
Neostigmine: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Neostigmine; Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects. (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Netupitant, Fosnetupitant; Palonosetron: (Moderate) Netupitant is a moderate inhibitor of CYP3A4 and should be used with caution in patients receiving concomitant medications that are primarily metabolized through CYP3A4, such as clomipramine. The plasma concentrations of clomipramine can increase when co-administered with netupitant; the inhibitory effect on CYP3A4 can last for multiple days.
Niraparib; Abiraterone: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if coadministration with abiraterone is necessary; a dose reduction of clomipramine may be necessary. Clomipramine is a CYP2D6 substrate and abiraterone is a moderate CYP2D6 inhibitor. Patients who are stable on a given dose of clomipramine may become abruptly toxic when given abiraterone is concomitant therapy.
Nirmatrelvir; Ritonavir: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with ritonavir is necessary; a dose reduction of the TCA may be necessary. Concurrent use may increase exposure of the TCA. TCAs are CYP2D6 substrates and ritonavir is a CYP2D6 inhibitor.
Nitroglycerin: (Minor) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as antidepressants. Patients should be monitored more closely for hypotension if nitroglycerin is used concurrently with antidepressants.
Non-Ionic Contrast Media: (Major) Use of medications that lower the seizure threshold should be carefully evaluated when considering the use of intrathecal radiopaque contrast agents. Tricyclic antidepressants should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Norepinephrine: (Major) Avoid coadministration of norepinephrine with tricyclic antidepressants as concurrent use can cause severe, prolonged hypertension. If administration of norepinephrine cannot be avoided in these patients, monitor for hypertension.
Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Norethindrone; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Norgestimate; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Obeticholic Acid: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of obeticholic acid is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and obeticholic acid is a CYP1A2 inhibitor.
Olanzapine: (Moderate) Olanzapine or tricyclic antidepressants, at elevated serum concentrations, may prolong the QTc interval. In addition, anticholinergic effects and sedation may be seen when tricyclic antidepressants are used with olanzapine.
Olanzapine; Fluoxetine: (Moderate) Coadministration of fluoxetine and clomipramine may increase the risk for QT prolongation, torsade de pointes (TdP), and serotonin syndrome. If serotonin syndrome is suspected, discontinue fluoxetine and concurrent serotonergic agents and initiate appropriate medical treatment. QT prolongation and TdP have been reported in patients treated with fluoxetine. Tricyclics, particularly at elevated concentrations, are associated with a possible risk of QT prolongation and TdP. (Moderate) Olanzapine or tricyclic antidepressants, at elevated serum concentrations, may prolong the QTc interval. In addition, anticholinergic effects and sedation may be seen when tricyclic antidepressants are used with olanzapine.
Olanzapine; Samidorphan: (Moderate) Olanzapine or tricyclic antidepressants, at elevated serum concentrations, may prolong the QTc interval. In addition, anticholinergic effects and sedation may be seen when tricyclic antidepressants are used with olanzapine.
Oliceridine: (Major) Concomitant use of oliceridine with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of oliceridine with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Omeprazole: (Minor) Coadministration may result in increased clomipramine exposure. Omeprazole is a CYP2C19 inhibitor and clomipramine is a CYP2C19 substrate.
Omeprazole; Amoxicillin; Rifabutin: (Minor) Coadministration may result in increased clomipramine exposure. Omeprazole is a CYP2C19 inhibitor and clomipramine is a CYP2C19 substrate.
Omeprazole; Sodium Bicarbonate: (Minor) Coadministration may result in increased clomipramine exposure. Omeprazole is a CYP2C19 inhibitor and clomipramine is a CYP2C19 substrate.
Opicapone: (Major) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including tricyclic antidepressants, due to the possibility of additive sedation. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment. Patients should be advised to avoid driving or other tasks requiring mental alertness until they know how the combination affects them.
Oritavancin: (Moderate) Coadministration of oritavancin and clomipramine may result in increases or decreases in clomipramine exposure and may increase side effects or decrease efficacy of clomipramine. Clomipramine is primarily metabolized by CYP3A4 and CYP2D6 but is also metabolized by CYP2C19. Oritavancin weakly induces CYP3A4 and CYP2D6, while weakly inhibiting CYP2C19. If these drugs are administered concurrently, monitor the patient for signs of toxicity or lack of efficacy.
Orphenadrine: (Moderate) Orphenadrine should be combined cautiously with tricyclic antidepressants due to the potential for additive anticholinergic and CNS depressant effects. Antimuscarinic effects might be seen on GI smooth muscle, bladder function, the eye, and temperature regulation. Consider an alternative skeletal muscle relaxant.
Osilodrostat: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if coadministration with osilodrostat is necessary; a dose reduction of clomipramine may be necessary. Concurrent use may increase exposure of clomipramine. Additionally, consider more frequent ECG monitoring due to the risk of additive QT prolongation. Clomipramine is a CYP2D6 substrate that may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Osilodrostat is a CYP2D6 inhibitor that is associated with dose-dependent QT prolongation.
Osimertinib: (Major) If possible, avoid coadministration of clomipramine and osimertinib due to the risk of QT prolongation and torsade de pointes (TdP). If concomitant use is unavoidable, periodically monitor electrolytes and ECGs for QT prolongation; an interruption of osimertinib therapy and dose reduction may be necessary if QT prolongation occurs. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Concentration-dependent QTc prolongation also occurred during clinical trials of osimertinib.
Oxazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Oxcarbazepine: (Moderate) Use clomipramine with caution in patients with a history of seizures; clomipramine may lower the seizure threshold and thus potentially interfere with the ability of antiepileptics to control seizures. In addition, concomitant use of clomipramine and oxcarbazepine may result in additive CNS depression. Oxcarbazepine, a CYP2C19 inhibitor, can increase plasma concentrations of clomipramine, a substrate of CYP2C19.
Oxybutynin: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and oxybutynin use. Concomitant use may result in additive anticholinergic adverse effects.
Oxycodone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Oxymorphone: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. The anticholinergic properties of tricyclic antidepressants may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Reduce the initial oxymorphone dosage by 1/3 to 1/2. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome. Monitor for signs of urinary retention and reduced gastric motility.
Ozanimod: (Contraindicated) Do not use tricyclic antidepressants (TCAs) in patients taking MAOIs or within 14 days of stopping them. An active metabolite of ozanimod inhibits MAO-B, and interactions with TCAs may manifest as serotonin syndrome, hypertensive crisis, QT prolongation or other serious side effects. Hyperpyretic crises, severe convulsions, and deaths have occurred in patients receiving TCAs and MAO inhibiting drugs simultaneously. Consider an alternative to the TCA. Ozanimod is a monoamine oxidase inhibitor that may result in a transient decrease in heart rate and atrioventricular conduction delays. Ozanimod has not been studied in patients taking concurrent QT prolonging drugs; however, QT prolonging drugs have been associated with TdP in patients with bradycardia. TCAs are serotonergic drugs that share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Pacritinib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of pacritinib is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and pacritinib is a CYP1A2 inhibitor.
Paliperidone: (Moderate) Concurrent use of paliperidone and tricyclic antidepressants should be avoided if possible. Paliperidone has a risk for QT prolongation and torsade de pointes, and tricyclic antidepressants, primarily at elevated serum concentrations, may produce clinically significant prolongation of the QTc interval. In addition, there is a potential for other pharmacodynamic interactions, such as augmentation of CNS impairment.
Panobinostat: (Minor) The co-administration of panobinostat with tricyclic antidepressants such as clomipramine is not recommended; QT prolongation has been reported with both of these agents. If concomitant use cannot be avoided, closely monitor patients for signs and symptoms of tricyclic antidepressant toxicity, including QT prolongation and cardiac arrhythmias. Panobinostat is a CYP2D6 inhibitor and tricyclic antidepressants are CYP2D6 substrates. When a single-dose of a CYP2D6-sensitive substrate was administered after 3 doses of panobinostat (20 mg given on days 3, 5, and 8), the CYP2D6 substrate Cmax increased by 20% to 200% and the AUC value increased by 20% to 130% in 14 patients with advanced cancer; exposure was highly variable (coefficient of variance > 150%).
Paroxetine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering selective serotonin reuptake inhibitors (SSRIs) with other drugs that have serotonergic properties such as tricyclic antidepressants. In addition, paroxetine is a potent CYP2D6 inhibitor and may decrease the metabolism of clomipramine, a CYP2D6 substrate. Because there is a risk of QT prolongation and torsade de pointes (TdP) with tricyclics at elevated serum concentrations, coadministration should be approached with caution and close monitoring. Lastly, both paroxetine and clomipramine may exhibit significant anticholinergic effects that may be additive during concurrent use.
Pazopanib: (Minor) Coadministration of pazopanib and other drugs that prolong the QT interval, such as tricyclic antidepressants is not advised; pazopanib has been reported to prolong the QT interval. If pazopanib and the other drug must be continued, closely monitor the patient for QT interval prolongation. In addition, pazopanib is a weak inhibitor of CYP3A4. Amitriptyline, clomipramine and imipramine are CYP3A4 substrates. Coadministration of pazopanib may cause an increase in systemic concentrations of the tricyclic antidepressant. Use caution when administering these drugs concomitantly.
Peginterferon Alfa-2b: (Moderate) Monitor for adverse effects associated with increased exposure to clomipramine if peginterferon alfa-2b is coadministered. Peginterferon alfa-2b is a CYP2D6 inhibitor, while clomipramine is a CYP2D6 substrate.
Pentazocine; Naloxone: (Moderate) Pain medications such as pentazocine should be combined cautiously with tricyclic antidepressants due to the possibility of additive CNS depression, respiratory depression, hypotension, or decreased intestinal motility. Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering tricyclic antidepressants with other drugs that have serotonergic properties such as pentazocine. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, tricyclic antidepressant and concurrent serotonergic agents should be discontinued.
Pentobarbital: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Perampanel: (Moderate) Co-administration of perampanel with CNS depressants, including ethanol, may increase CNS depression. The combination of perampanel (particularly at high doses) with ethanol has led to decreased mental alertness and ability to perform complex tasks (such as driving), as well as increased levels of anger, confusion, and depression; similar reactions should be expected with concomitant use of other CNS depressants, such as clomipramine. In addition, tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, may also lower the seizure threshold, leading to pharmacodynamic interactions.
Perphenazine: (Moderate) During coadministration of tricyclic antidepressants (TCAs) and perphenazine, close monitoring is essential and dose reduction may become necessary to avoid toxicity. Phenothiazines have been reported to prolong the QT interval. Because tricyclic antidepressants are associated with a possible risk for QT prolongation and torsade de pointes when given in excessive doses or overdosage, concurrent use with phenothiazines should be approached with caution. Additive anticholinergic effects or sedation may also occur.
Perphenazine; Amitriptyline: (Moderate) During coadministration of tricyclic antidepressants (TCAs) and perphenazine, close monitoring is essential and dose reduction may become necessary to avoid toxicity. Phenothiazines have been reported to prolong the QT interval. Because tricyclic antidepressants are associated with a possible risk for QT prolongation and torsade de pointes when given in excessive doses or overdosage, concurrent use with phenothiazines should be approached with caution. Additive anticholinergic effects or sedation may also occur.
Phendimetrazine: (Major) Avoid use of tricyclic antidepressants with phendimetrazine whenever possible. Tricyclic antidepressants (TCAs) may potentiate the pressor response to sympathomimetic agents, such as phendimetrazine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience side effects like hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. Patients should be closely monitored if use together is unavoidable.
Phenelzine: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders are contraindicated for use with tricyclic antidepressants (TCAs) or within 14 days of discontinuing treatment with a TCA. Conversely, TCAs should not be initiated within 14 days of stopping an MAOI. Monitor for serotonin-related side effects during therapy transitions.
Phenobarbital: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and scopolamine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects. (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Phentermine: (Moderate) Monitor blood pressure and heart rate during concomitant phentermine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. Concomitant use increases the risk for potentiation of cardiovascular effects. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Phentermine; Topiramate: (Moderate) Monitor blood pressure and heart rate during concomitant phentermine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. Concomitant use increases the risk for potentiation of cardiovascular effects. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain. (Moderate) Monitor for unusual drowsiness or excess sedation during concomitant clomipramine and topiramate use due to the risk for additive CNS depression.
Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat.
Phenytoin: (Moderate) Tricyclic antidepressants (TCA), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently. In addition, hydantoins may increase TCA metabolism.
Physostigmine: (Moderate) Tricyclic antidepressants may antagonize some of the effects of cholinesterase inhibitors due to their anticholinergic activity. It may be helpful to choose an alternative antidepressant with lower propensity for anticholinergic activity.
Pilocarpine: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Pimozide: (Contraindicated) Pimozide is associated with a well-established risk of QT prolongation and torsade de pointes (TdP). Because of the potential for TdP, use of tricyclic antidepressants with pimozide is contraindicated.
Pitolisant: (Major) Avoid coadministration of pitolisant with tricyclic antidepressants (TCAs) as the effect of pitolisant may be decreased; concurrent use may also increase the risk of QT prolongation. Pitolisant increases histamine concentrations in the brain; therefore, H1-receptor antagonists like TCAs, may reduce pitolisant efficacy. Pitolisant prolongs the QT interval. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Porfimer: (Major) Avoid coadministration of porfimer with tricyclic antidepressants due to the risk of increased photosensitivity. All patients treated with porfimer will be photosensitive. Concomitant use of other photosensitizing agents like tricyclic antidepressants may increase the risk of a photosensitivity reaction.
Posaconazole: (Minor) Posaconazole is associated with QT prolongation. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, posaconazole inhibits CYP3A4, CYP2C19, and CYP3A4 may be partially involved in the metabolism of TCAs. Fluconazole has been reported to increase the effects of amitriptyline, perhaps through inhibition of the hepatic microsomal CYP2C19 or CYP3A4 isoenzymes. In at least one case, the interaction resulted in an increased incidence of TCA-related side effects, such as dizziness and syncope. In another case, QT-prolongation and torsades de pointes occurred. Monitor for an increased response to amitriptyline if fluconazole, posaconazole, or voriconazole are coadministered.
Pralidoxime: (Moderate) Tricyclic antidepressants (TCAs) may antagonize some of the effects of parasympathomimetics (e.g., cholinesterase inhibitors) due to their anticholinergic activity. However, parasympathomimetics like bethanechol have occasionally been used historically to offset some of the adverse peripheral antimuscarinic (anticholinergic) effects of TCAs, such as dry mouth, constipation, or urinary retention. For years, physostigmine was used as an adjunct to the treatment of TCA overdose; however, its efficacy was limited to addressing anticholinergic effects. Additionally, case reports suggest that harmful effects such as seizures and bradyarrhythmias progressing to asystole, especially in patients with cardiac conduction abnormalities at baseline, are possible. For these reasons, physostigmine is no longer considered a standard of care in the treatment of TCA overdose.
Pramipexole: (Moderate) Pramipexole may cause additive drowsiness when combined with tricyclic antidepressants.
Pramlintide: (Major) Pramlintide slows gastric emptying and the rate of nutrient delivery to the small intestine. Medications with the potential to slow GI motility, such as tricyclic antidepressants, should be used with caution, if at all, with pramlintide until more data are available from the manufacturer. Monitor blood glucose.
Pregabalin: (Major) Initiate pregabalin at the lowest recommended dose and monitor patients for symptoms of sedation and somnolence during coadministration of pregabalin and tricyclic antidepressants. Concomitant use of pregabalin with tricyclic antidepressants may cause additive CNS depression. Educate patients about the risks and symptoms of excessive CNS depression.
Prilocaine: (Major) Use prilocaine and tricyclic antidepressants together with caution. If epinephrine is added to prilocaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. Administration of a phenothiazine or a butyrophenone may reduce or reverse the pressor effect of epinephrine.
Prilocaine; Epinephrine: (Major) Avoid use of epinephrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the vasopressor effects of epinephrine. (Major) Use prilocaine and tricyclic antidepressants together with caution. If epinephrine is added to prilocaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. Administration of a phenothiazine or a butyrophenone may reduce or reverse the pressor effect of epinephrine.
Primidone: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Procarbazine: (Major) In general, drugs with MAOI activity, such as procarbazine, should not be used with tricyclic antidepressants. Severe hypertensive crises, serotonin syndrome, or increased anticholinergic effects can result from concomitant use. Tricyclic antidepressants can, in some cases, be used concomitantly with MAOIs if tricyclic antidepressant therapy is in effect prior to beginning therapy with a MAOI; tricyclic antidepressants should never be added to an existing MAOI regime. Under careful monitoring for signs or symptoms of hypertension, add the MAOI gradually, starting at a low dose. Patients should also be monitored closely for signs or symptoms of serotonin syndrome (characterized by hyperthermia, diaphoresis, shivering, tremor, myoclonus, seizures, ataxia, delirium, restlessness). Strict adherence to diet restrictions should be emphasized and the patient should not be receiving other sympathomimetics. Most references suggest avoiding this drug interaction entirely if clomipramine or imipramine are being administered.
Prochlorperazine: (Moderate) When prescribing tricyclic antidepressants (TCAs) to patients already receiving phenothiazine therapy, close monitoring is essential and dose reduction may become necessary to avoid toxicity. Phenothiazines have been reported to prolong the QT interval. Because tricyclic antidepressants are associated with a possible risk for QT prolongation and TdP when given in excessive doses or overdosage, concurrent use with phenothiazines should be approached with caution. Lower doses than usually prescribed for either the phenothiazine or the TCA may be required. Additive anticholinergic effects and sedation may also occur.
Promethazine: (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant promethazine and tricyclic antidepressant use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Promethazine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering dextromethorphan with tricyclic antidepressants. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustments. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant promethazine and tricyclic antidepressant use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Promethazine; Phenylephrine: (Major) Tricyclic antidepressants (TCAs) may markedly enhance the pressor response to parenteral direct-acting sympathomimetic agents such as norepinephrine and, to a lesser extent, epinephrine and phenylephrine. TCAs inhibit norepinephrine reuptake in adrenergic neurons, resulting in increased stimulation of adrenergic receptors. Clinically, the patient might experience hypertension, headache, tremor, palpitations, chest pain, or irregular heartbeat. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant promethazine and tricyclic antidepressant use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Propafenone: (Minor) Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). This pharmacologic property of the TCAs is of concern in patients with significant cardiac histories or treated with selected cardiac agents. Cases of long QT syndrome and torsade de pointes (TdP) tachycardia have been described with TCA use, but rarely occur when TCAs are used alone in normal prescribed doses and in the absence of other known risk factors for QT prolongation. Limited data are available regarding the safety of TCAs in combination with other QT-prolonging drugs. One study reported the common occurrence of overlapping prescriptions for 2 or more drugs with potential for QT-prolonging effects; antidepressants were involved in nearly 50% of the cases, but there are little data to document safety of the combined therapies. Certain cardiac drugs prolong repolarization at therapeutic or elevated plasma concentrations, and the addition of other drugs may increase the risk of QT prolongation and TdP via pharmacokinetic or pharmacodynamic interactions. TCAs should be used cautiously and with close monitoring in combination with cardiac drugs known to prolong the QT interval such as propafenone. The need to coadminister TCAs with propafenone should be done with a careful assessment of risk versus benefit; consider alternative therapy to the TCA.
Propantheline: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and propantheline use. Concomitant use may result in additive anticholinergic adverse effects.
Propofol: (Moderate) General anesthetics like propofol may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Pseudoephedrine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines.
Pseudoephedrine; Triprolidine: (Major) Avoid use of pseudoephedrine and tricyclic antidepressants as tricyclic antidepressants may potentiate the effects of catecholamines. (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Pyridostigmine: (Moderate) Tricyclic antidepressants may antagonize some of the effects of parasympathomimetics, such as pyridostigmine, due to their anticholinergic activity.
Quazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Quinidine: (Contraindicated) Quinidine administration is associated with QT prolongation and torsade de pointes (TdP). Quinidine inhibits CYP2D6 and has QT-prolonging actions. Quinidine is contraindicated with other drugs that prolong the QT interval and are metabolized by CYP2D6 as the effects on the QT interval may be increased during concurrent use of these agents. Tricyclic antidepressants are associated with a possible risk of QT prolongation, particularly at high dosages or in overdose, and are substrates for CYP2D6.
Quinine: (Major) Quinine has been associated with QT prolongation and rare cases of torsade de pointes (TdP). In addition, quinine is an inhibitor of CYP2D6. Avoid concurrent use of quinine with other drugs that prolong the QT and are CYP2D6 substrates. Coadministration may result in elevated plasma concentrations of the interacting drug, causing increased risk for adverse events, such as QT prolongation. Drugs that prolong the QT and are substrates for CYP2D6 include tricyclic antidepressants.
Racepinephrine: (Major) Tricyclic antidepressants (TCAs) and maprotiline potentiate the effects of sympathomimetics including epinephrine. Enhanced cardiovascular effects including arrhythmias, severe hypertension, and/or hyperpyrexia are possible with combined use. Concomitant use of racepinephrine inhalations with these agents should be avoided when possible; use caution when concomitant use is not avoidable. If a patient is taking these antidepressants, then they should seek health care professional advice prior to the use of racepinephrine.
Ranolazine: (Major) Ranolazine is associated with dose- and plasma concentration-related increases in the QTc interval. The mean increase in QTc is about 6 milliseconds, measured at the tmax of the maximum dosage (1000 mg PO twice daily). However, in 5% of the population studied, increases in the QTc of at least 15 milliseconds have been reported. Although there are no studies examining the effects of ranolazine in patients receiving other QT prolonging drugs, coadministration of such drugs may result in additive QT prolongation. In addition, ranolazine and/or metabolites are moderate inhibitors of CYP2D6 isoenzymes. Based on drug interaction studies with metoprolol, a CYP2D6 substrate, ranolazine may theoretically increase plasma concentrations of CYP2D6 substrates and could lead to toxicity for drugs that have a narrow therapeutic range. The manufacturer for ranolazine suggests that lower doses of CYP2D6 substrates may be required during ranolazine treatment. Drugs that are CYP2D6 substrates that also have a possible risk for QT prolongation and TdP that should be used cautiously with ranolazine include tricyclic antidepressants.
Rasagiline: (Major) It is recommended to avoid concurrent use of rasagiline and antidepressants, including tricyclic antidepressants or related compounds (e.g., amoxapine, maprotiline). Severe CNS toxicity with hyperpyrexia has been reported during concurrent use of antidepressants and selective or non-selective MAOIs. During post-marketing use of rasagiline, non-fatal cases of serotonin syndrome have been reported during concomitant antidepressant administration. At least 2 weeks should elapse between stopping rasagiline treatment and beginning therapy with any tricyclic antidepressants or related compounds. Conversely, when discontinuing a tricyclic or related compound, it is advisable to wait the length of 4-5 half lives of the individual agent being discontinued prior to initiation with rasagiline.
Relugolix; Estradiol; Norethindrone acetate: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Remifentanil: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. The anticholinergic properties of tricyclic antidepressants may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome. Monitor for signs of urinary retention and reduced gastric motility.
Remimazolam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Ribociclib: (Major) Avoid coadministration of ribociclib with clomipramine due to an increased risk for QT prolongation. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Concomitant use may increase the risk for QT prolongation.
Ribociclib; Letrozole: (Major) Avoid coadministration of ribociclib with clomipramine due to an increased risk for QT prolongation. Ribociclib has been shown to prolong the QT interval in a concentration-dependent manner. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Concomitant use may increase the risk for QT prolongation.
Rifampin: (Moderate) It may be necessary to adjust the dosage of tricyclic antidepressants if given concurrently with rifampin. Rifampin may induce the metabolism of tricyclic antidepressants; coadministration may result in decreased tricyclic antidepressant plasma concentrations.
Rifapentine: (Major) Rifapentine induces hepatic isoenzymes CYP3A4 and CYP2C8/9. Tricyclic antidepressants are metabolized by CYP3A4 and CYP2C8/9 and may require dosage adjustments when administered concurrently with rifapentine.
Risperidone: (Moderate) Use risperidone and tricyclic antidepressants together with caution due to the potential for additive QT prolongation and risk of torsade de pointes (TdP). Additionally, coadministration may result in additive CNS effects. Risperidone has been associated with a possible risk for QT prolongation and/or TdP, primarily in the overdose setting. Tricyclic antidepressants share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations).
Ritlecitinib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of ritlecitinib is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and ritlecitinib is a CYP1A2 inhibitor.
Ritonavir: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with ritonavir is necessary; a dose reduction of the TCA may be necessary. Concurrent use may increase exposure of the TCA. TCAs are CYP2D6 substrates and ritonavir is a CYP2D6 inhibitor.
Rivastigmine: (Moderate) Concurrent use of tricyclic antidepressants and rivastigmine should be avoided if possible. Rivastigmine inhibits acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, and improves the availability of acetylcholine. Tricyclic antidepressants with significant anticholinergic activity, such as amitriptyline, imipramine, doxepin, and clomipramine, are more likely to interfere with the therapeutic effect of rivastigmine than other tricyclics.
Rizatriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Rolapitant: (Major) Monitor for increased serum concentrations of clomipramine and for clomipramine-related adverse effects, such as nausea, dizziness, hypotension, syncope, and QT prolongation, if coadministered with rolapitant. Lower doses of either drug may be required with coadministration. When rolapitant is withdrawn from co-therapy, an increased dose of clomipramine may be required. Clomipramine is a CYP2D6 substrate and rolapitant is a moderate CYP2D6 inhibitor; the inhibitory effect of rolapitant is expected to persist beyond 28 days for an unknown duration. Exposure to another CYP2D6 substrate, following a single dose of rolapitant increased about 3-fold on Days 8 and Day 22. The inhibition of CYP2D6 persisted on Day 28 with a 2.3-fold increase in the CYP2D6 substrate concentrations, the last time point measured.
Ropinirole: (Moderate) Ropinirole may cause additive drowsiness when combined with tricyclic antidepressants.
Rucaparib: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concurrent use of rucaparib is necessary as plasma concentrations of clomipramine may increase; a dose reduction of clomipramine may be necessary. Clomipramine is a CYP2D6 and CYP1A2 substrate; rucaparib is a weak CYP2D6 inhibitor and a moderate CYP1A2 inhibitor.
Rufinamide: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Safinamide: (Contraindicated) Safinamide is contraindicated for use with tricyclic antidepressants (TCAs) due to the risk of serotonin syndrome. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. At least 14 days should elapse between the discontinuation of safinamide and the initiation of a TCA.
Saquinavir: (Minor) The concurrent use of saquinavir boosted with ritonavir and tricyclic antidepressants should be avoided if possible due to the potential for increased tricyclic antidepressant serum concentrations and the potential for QT prolongation. Saquinavir boosted with ritonavir is a potent inhibitor of CYP3A4, an isoenzyme partially responsible for the metabolism of many tricyclic antidepressants. During coadministration, elevated serum concentrations of the tricyclic antidepressant can occur; thus, monitoring of therapeutic concentrations is recommended by the manufacturer of saquinavir. Additionally, saquinavir boosted with ritonavir causes dose-dependent QT and PR prolongation; if possible, avoid use with other drugs that may prolong the QT or PR interval, such as tricyclic antidepressants. If no alternative therapy is acceptable, perform a baseline ECG prior to initiation of concomitant therapy and follow recommended ECG monitoring.
Scopolamine: (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and scopolamine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Secobarbital: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions. In addition, pharmacokinetic interactions may occur. Barbiturates may increase TCA metabolism. Monitor patients during concurrent use.
Segesterone Acetate; Ethinyl Estradiol: (Minor) The oxidative metabolism of tricyclic antidepressants may be decreased by ethinyl estradiol. Increased antidepressant serum concentrations may occur. Ethinyl estradiol has been reported to intensify side effects from imipramine. Patients should be monitored for increased tricyclic antidepressant side effects if an estrogen is added. Current evidence indicates that this interaction may be related to the estrogen dosage, with larger doses (i.e., >= 50 mcg ethinyl estradiol/day) causing a more significant interaction.
Selegiline: (Contraindicated) Tricyclic antidepressants (TCAs) are contraindicated for use with selegiline, a selective monoamine oxidase type B inhibitor (MAO-B inhibitor). At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with a TCA. After stopping treatment with a TCA, a time period equal to 4 to 5 half-lives of the TCA or any active metabolite should elapse before starting therapy with selegiline. Serotonin syndrome has occurred in patients receiving selective MAO-B inhibitors and such antidepressants simultaneously.
Serdexmethylphenidate; Dexmethylphenidate: (Moderate) Caution should be observed when coadministering methylphenidate derivatives and tricyclic antidepressants (TCAs). There are postmarketing reports of serotonin syndrome occurring during use of methylphenidate derivatives and other serotonergic medications. Patients receiving this combination should be monitored for the emergence of serotonin syndrome. If serotonin syndrome occurs, all serotonergic agents should be discontinued and appropriate medical management should be implemented.
Serotonin-Receptor Agonists: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Sertraline: (Major) There have been postmarketing reports of QT prolongation and torsade de pointes (TdP) during treatment with sertraline and the manufacturer of sertraline recommends avoiding concurrent use with drugs known to prolong the QTc interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, serotonin syndrome is possible when coadministering drugs that have serotonergic properties such as sertraline and TCAs. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Lastly, sertraline is a CYP2D6 inhibitor, one of the isoenzymes responsible for the metabolism of TCAs. During a study evaluating the effects of concurrent use of sertraline and low-dose doxepin (6 mg) in healthy subjects, the doxepin mean AUC and Cmax estimates were about 21% and 32% higher, respectively, during concomitant sertraline administration than in those receiving doxepin alone. Measurements of psychomotor function showed more impairment in the combination group than the group receiving doxepin alone; however, subjective measures of alertness were similar between the two groups. Patients receiving a tricyclic antidepressant should be monitored closely for toxicity if sertraline is added. The American Heart Association has published guidelines regarding cardiovascular monitoring of certain psychotropic drug combinations in children.
Sevoflurane: (Minor) Tricyclic antidepressants (TCAs) should be used cautiously and with close monitoring with halogenated anesthetics. Halogenated anesthetics can prolong the QT interval. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, general anesthetics may produce additive CNS depression when used in patients taking tricyclic antidepressants.
Sodium picosulfate; Magnesium oxide; Anhydrous citric acid: (Minor) There have been reports of generalized tonic-clonic seizures with the use of bowel preparation products in patients with no prior history of seizures. While seizures have generally been associated with electrolyte abnormalities, such as hyponatremia, hypokalemia, hypocalcemia, and hypomagnesemia, and low serum osmolarity, patients receiving medications that lower the seizure threshold may be at an increased risk for experiencing seizures with bowel preparation products.
Solifenacin: (Moderate) Additive anticholinergic effects may be seen when drugs with antimuscarinic properties like solifenacin are used concomitantly with tricyclic antidepressants. Clinicians should note that additive antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function, the CNS, the eye, and temperature regulation. Additive drowsiness may also occur, depending on the interacting agent. In addition, solifenacin is associated with dose-dependent QT prolongation, and torsades de pointes (TdP) has been reported with post-marketing use. Tricyclic antidepressants also are associated with QT prolongation and should be used cautiously and with close monitoring with solifenacin.
St. John's Wort, Hypericum perforatum: (Moderate) Monitor patients for the emergence of serotonin syndrome or for loss of tricyclic antidepressant (TCA) efficacy if concomitant use of TCAs and St. John's wort is warranted. The concomitant use of TCAs with other serotonergic drugs has resulted in serotonin syndrome. Also monitor patients for reduced efficacy of TCAs if used together. TCAs are metabolized by several hepatic isoenzymes, including CYP3A and CYP1A2 and St. John's wort is a strong inducer of these enzymes.
Stiripentol: (Moderate) Monitor for excessive sedation and somnolence during coadministration of stiripentol and tricyclic antidepressants. CNS depressants can potentiate the effects of stiripentol.
Sufentanil: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Monitor for loss of tricyclic antidepressant efficacy during concomitant sulfamethoxazole; trimethoprim use; adjust the tricyclic antidepressant dose if needed. The efficacy of tricyclic antidepressants can decrease during concomitant use. (Moderate) Monitor therapeutic response and adjust the tricyclic antidepressant dose, if needed, when use sulfamethoxazole; trimethoprim concomitantly. The efficacy of tricyclic antidepressants can decrease when administered with sulfamethoxazole; trimethoprim.
Sumatriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Sumatriptan; Naproxen: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Suvorexant: (Moderate) The use of suvorexant with other CNS depressants (e.g., tricyclic antidepressants) increases the risk of CNS depression. Dosage adjustments of suvorexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive effects. The use of suvorexant with other drugs to treat insomnia, such as tricyclic antidepressants used for insomnia, is not recommended.
Tacrolimus: (Minor) Tacrolimus has been associated with QT prolongation. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Due to a possible risk for QT prolongation and torsade de pointes (TdP), tacrolimus and tricyclic antidepressants (TCAs) should be used together cautiously.
Tapentadol: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation, somnolence, and increased risk of serotonin syndrome. The anticholinergic properties of tricyclic antidepressants may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome. Monitor for signs of urinary retention and reduced gastric motility.
Tedizolid: (Minor) Caution is warranted with the concurrent use of tedizolid and tricyclic antidepressants (TCAs) due to the theoretical risk of serotonin syndrome. Animal studies did not predict serontoneric effects with tedizolid. However, tedizolid is an antibiotic that is a weak reversible, non-selective MAO inhibitor and monoamine oxidase type A deaminates serotonin; therefore, coadministration theoretically could lead to serious reactions including serotonin syndrome or neuroleptic malignant syndrome-like reactions. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
Temazepam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Terbinafine: (Moderate) In vitro studies have shown systemic terbinafine to inhibit hepatic isoenzyme CYP2D6, and thus may inhibit the clearance of drugs metabolized by this isoenzyme, such as tricyclic antidepressants.
Tetrabenazine: (Moderate) Tetrabenazine causes a small increase in the corrected QT interval (QTc). The manufacturer recommends avoiding concurrent use of tetrabenazine with other drugs known to prolong QTc such as tricyclic antidepressants. Tricyclic antidepressants (TCAs) share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, concurrent use of tricyclics and tetrabenazine should generally be avoided since the risk of adverse effects such as drowsiness, sedation, dizziness, or orthostatic hypotension may be increased.
Tetracaine: (Major) Use tetracaine and tricyclic antidepressants (TCAs) together with caution. If epinephrine is added to tetracaine, severe and prolonged hypertension may occur in a patient taking a TCA. Tricyclic antidepressants can increase the sensitivity to epinephrine by inhibiting epinephrine reuptake or metabolism. If concurrent therapy is necessary, carefully monitor the patient. Administration of a phenothiazine or a butyrophenone may reduce or reverse the pressor effect of epinephrine.
Thalidomide: (Major) Avoid the concomitant use of thalidomide with other central nervous system depressants such as tricyclic antidepressants (TCAs) due to the potential for additive sedative effects. Additionally, co-administration of thalidomide and other agents that slow cardiac conduction such as TCAs may increase the potential for additive bradycardia.
Thioridazine: (Contraindicated) Thioridazine is associated with a well-established risk of QT prolongation and torsades de pointes (TdP). Thioridazine is considered contraindicated for use along with agents that, when combined with a phenothiazine, may prolong the QT interval and increase the risk of TdP, and/or cause orthostatic hypotension, including tricyclic antidepressants (TCAs). In addition to additive effects on the cardiovascular system, additive anticholinergic effects and sedation may be observed.
Thiothixene: (Moderate) Concurrent use of thiothixene and tricyclic antidepressants (TCAs) may result in additive anticholinergic effects, sedation, and orthostatic hypotension. Additive effects may be more pronounced when thiothixene is used with tertiary TCAs including amitriptyline, clomipramine, doxepin, imipramine, and trimipramine versus secondary TCAs such as desipramine, nortriptyline, and protriptyline.
Thyroid hormones: (Minor) Thyroid hormones may increase receptor sensitivity and enhance the effects of tricyclic antidepressants. Although this drug combination appears to be safe, be aware of the possibility of exaggerated cardiovascular side effects such as arrhythmias and CNS stimulation.
Tiagabine: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold.
Tobacco: (Major) Advise patients to avoid smoking tobacco while taking tricyclic antidepressants (TCAs). Tobacco smoking may increase the clearance of TCAs, which may reduce their efficacy.
Tolcapone: (Major) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including tricyclic antidepressants, due to the possibility of additive sedation. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment. Patients should be advised to avoid driving or other tasks requiring mental alertness until they know how the combination affects them.
Tolterodine: (Moderate) Tricyclic antidepressants (TCAs) should be used cautiously and with close monitoring with tolterodine. TCAs share pharmacologic properties similar to the Class IA antiarrhythmic agents and may prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). Tolterodine is also associated with dose-dependent prolongation of the QT interval, especially in poor metabolizers of CYP2D6. In addition, additive anticholinergic effects may be seen when tricyclic antidepressants (TCAs) are used concomitantly with other antimuscarinics. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. Additive CNS effects are also possible when tolterodine is combined with tricyclic antidepressants.
Topiramate: (Moderate) Monitor for unusual drowsiness or excess sedation during concomitant clomipramine and topiramate use due to the risk for additive CNS depression.
Tramadol: (Major) Concomitant use of tramadol with tricyclic antidepressants may cause respiratory depression, hypotension, profound sedation, and death and increase the risk for serotonin syndrome, seizures, and anticholinergic effects. Limit the use of opioid pain medications to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Monitor patients for serotonin syndrome if concomitant use is necessary, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Monitor for signs of urinary retention or reduced gastric motility during coadministration. The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Tramadol; Acetaminophen: (Major) Concomitant use of tramadol with tricyclic antidepressants may cause respiratory depression, hypotension, profound sedation, and death and increase the risk for serotonin syndrome, seizures, and anticholinergic effects. Limit the use of opioid pain medications to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Monitor patients for serotonin syndrome if concomitant use is necessary, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Monitor for signs of urinary retention or reduced gastric motility during coadministration. The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Tranylcypromine: (Contraindicated) Due to the risk of serotonin syndrome, monoamine oxidase inhibitors (MAOIs) intended to treat psychiatric disorders are contraindicated for use with tricyclic antidepressants (TCAs) or within 14 days of discontinuing treatment with a TCA. Conversely, TCAs should not be initiated within 14 days of stopping an MAOI. Monitor for serotonin-related side effects during therapy transitions.
Trazodone: (Moderate) Monitor for unusual drowsiness and excess sedation and signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant trazodone and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for additive CNS depression and serotonin syndrome.
Triazolam: (Major) Limit dosage and duration of benzodiazepines during concomitant use with tricyclic antidepressants, and monitor patients closely for respiratory depression and sedation. Additive CNS depression may occur.
Trifluoperazine: (Moderate) Phenothiazines have been reported to prolong the QT interval. Because tricyclic antidepressants are associated with a possible risk for QT prolongation and TdP when given in excessive doses or overdosage, concurrent use with trifluoperazine should be approached with caution. If coadministration is considered necessary, and the patient has known risk factors for cardiac disease or arrhythmia, then close monitoring is essential. Additive anticholinergic effects or sedation may be seen when phenothiazines are used with tricyclic antidepressants.
Trihexyphenidyl: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant tricyclic antidepressant and trihexyphenidyl use. Concomitant use may result in additive anticholinergic adverse effects.
Trimethoprim: (Moderate) Monitor therapeutic response and adjust the tricyclic antidepressant dose, if needed, when use sulfamethoxazole; trimethoprim concomitantly. The efficacy of tricyclic antidepressants can decrease when administered with sulfamethoxazole; trimethoprim.
Triprolidine: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants are used concomitantly with sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation.
Trospium: (Moderate) Additive anticholinergic and CNS effects may be seen when tricyclic antidepressants (TCAs) are used concomitantly with other antimuscarinics, such as trospium. Antimuscarinic effects might be seen on GI smooth muscle, bladder function, the eye, and temperature regulation. While CNS-related side effects such as drowsiness and blurred vision are not typically noted with trospium, they may occur in some patients. Monitor for anticholinergic effects such as such as confusion, constipation, dizziness, urinary retention, dry mouth and eyes, blurred vision, or rarely, fast, irregular heartbeat.
Tryptophan, 5-Hydroxytryptophan: (Major) The concomitant use of tryptophan with tricyclic antidepressants should be avoided. Since tryptophan is converted to serotonin (5-hydroxytryptamine), the use of tryptophan in patients receiving drugs with serotonergic activity could lead to serotonin syndrome. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. If serotonin syndrome is suspected, the tricyclic antidepressant and concurrent serotonergic agents should be discontinued.
Valerian, Valeriana officinalis: (Moderate) Any substances that act on the CNS, including tricyclic antidepressants, may theoretically interact with valerian, Valeriana officinalis. The valerian derivative, dihydrovaltrate, binds at barbiturate binding sites; valerenic acid has been shown to inhibit enzyme-induced breakdown of GABA in the brain; the non-volatile monoterpenes (valepotriates) have sedative activity. Valerian is probably best avoided in combination with prescription antidepressants unless closely monitored by a health care professional.
Valproic Acid, Divalproex Sodium: (Moderate) Tricyclic antidepressants, when used concomitantly with valproic acid, can increase CNS depression and may lower the seizure threshold. Monitor patients on tricyclic antidepressants carefully when valproic acid is used concurrently.
Vasopressin, ADH: (Moderate) Monitor hemodynamics and adjust the dose of vasopressin as needed when used concomitantly with drugs suspected of causing syndrome of inappropriate antidiuretic hormone (SIADH), such as tricyclic antidepressants. Use together may increase the pressor and antidiuretic effects of vasopressin.
Venlafaxine: (Major) The combination of venlafaxine and tricyclic antidepressants may lead to serotonin syndrome and increased plasma concentrations of TCAs. Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering serotonin norepinephrine reuptake inhibitors (SNRIs) with other drugs that have serotonergic properties such as tricyclic antidepressants. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Venlafaxine is an inhibitor of CYP2D6, and many TCAs are metabolized by this isozyme. One case report documented a first-time seizure in a patient receiving venlafaxine and trimipramine at therapeutic dosages.
Verteporfin: (Moderate) Use caution if coadministration of verteporfin with tricyclic antidepressants is necessary due to the risk of increased photosensitivity. Verteporfin is a light-activated drug used in photodynamic therapy; all patients treated with verteporfin will be photosensitive. Concomitant use of other photosensitizing agents like antidepressants may increase the risk of a photosensitivity reaction.
Vigabatrin: (Moderate) Tricyclic antidepressants (TCAs), when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold, leading to pharmacodynamic interactions.
Vilazodone: (Major) Vilazodone and Tricyclic antidepressants (TCAs) may cause additive CNS depression, including dizziness or drowsiness. These drugs can represent duplicate therapies and are not commonly prescribed together. In addition, because of the potential risk and severity of serotonin syndrome, caution should be observed. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Patients receiving vilazodone and a TCA should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. Vilazodone and the TCA should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
Viloxazine: (Moderate) Monitor for an increase in tricyclic antidepressant (TCA)-related adverse reactions if coadministration with viloxazine is necessary; a dose reduction of TCA may be necessary. Concurrent use may increase the exposure of TCAs which are CYP2D6 substrates; viloxazine is a CYP2D6 inhibitor.
Voriconazole: (Minor) Due to the potential for QT prolongation and torsade de pointes (TdP), caution is advised when administering voriconazole with clomipramine. Voriconazole has been associated with prolongation of the QT interval and rare cases of arrhythmias, including TdP. Tricyclic antidepressants (TCAs), such as clomipramine, share pharmacologic properties similar to the Class IA antiarrhythmic agents and may also prolong the QT interval, particularly in overdose or with higher-dose prescription therapy (elevated serum concentrations). In addition, voriconazole inhibits CYP3A4 and clomipramine is a CYP3A4 substrate. Coadministation may increase the serum concentrations of clomipramine.
Vortioxetine: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering vortioxetine with other drugs that have serotonergic properties such as tricyclic antidepressants. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome. Patients receiving a tricyclic antidepressant in combination with vortioxetine should be monitored for the emergence of serotonin syndrome or other adverse effects. If serotonin syndrome is suspected, vortioxetine and concurrent serotonergic agents should be discontinued.
Zaleplon: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of tricyclic antidepressants and zaleplon due to the risk for additive CNS depression and next-day psychomotor impairment; dose adjustments may be necessary. Coadministration of single doses of a tricyclic antidepressant and zaleplon produced additive effects on decreased alertness and impaired psychomotor performance for 2 to 4 hours after administration.
Ziconotide: (Moderate) Due to potentially additive effects, dosage adjustments may be necessary if ziconotide is used with a drug that has CNS depressant effects such as tricyclic antidepressants. Coadministration of CNS depressants may increase drowsiness, dizziness, and confusion that are associated with ziconotide.
Zileuton: (Moderate) Monitor for an increase in clomipramine-related adverse reactions if concomitant use of zileuton is necessary; a clomipramine dose reduction may be necessary. Concomitant use may increase clomipramine exposure; clomipramine is a CYP1A2 substrate and zileuton is a CYP1A2 inhibitor.
Zolmitriptan: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant serotonin-receptor agonist and tricyclic antidepressant use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Zolpidem: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of tricyclic antidepressants and zolpidem due to the risk for additive CNS depression and next-day psychomotor impairment; dose adjustments may be necessary. Limit the dose of Intermezzo sublingual tablets to 1.75 mg/day. Coadministration of a tricyclic antidepressant and zolpidem resulted in a 20% decrease in the peak concentrations of the tricyclic antidepressant, but there was an additive effect of decreased alertness.
Zonisamide: (Moderate) Tricyclic antidepressants, when used concomitantly with anticonvulsants, can increase CNS depression and may also lower the seizure threshold. Monitor patients on anticonvulsants carefully when a TCA is used concurrently.
Zuranolone: (Moderate) Concomitant use of multiple sedating agents, such as zuranolone and tricyclic antidepressants, may result in additive CNS depression. Monitor for additive CNS depressant effects and consider taking additional steps to minimize the risk for over sedation, such as avoidance or a downward dose adjustment of either or both medications, especially in patients with additional risk factors for sedation-related harm.
The concise action of tricyclic antidepressants is not fully understood, but it is believed that their most important effect is to enhance the actions of norepinephrine and serotonin by blocking the reuptake of these neurotransmitters at the neuronal membrane. Of the tricyclic antidepressants, clomipramine is the most selective and potent inhibitor of serotonin (5-HT) reuptake. (Fluoxetine and related agents are also serotonin-specific.)
Recent evidence suggests that the upset of monoamine output exhibited by depressed patients may be regulated by long-term antidepressant treatment due to action on beta-adrenergic receptors. This action on beta-receptors may be a better explanation than the reuptake theory of these agents' antidepressant effects. Monoamine oxidase is not inhibited by clomipramine. Tricyclic antidepressants do not affect dopamine reuptake. Varying degrees of sedation can be produced, and the seizure threshold can be lowered. Anticholinergic activity is moderate. Cardiac dysrhythmias can result from the direct quinidine-like effect on cardiac function combined with anticholinergic activity and norepinephrine potentiation. Changes in sex hormone concentrations and blood glucose can result from clomipramine's effect on the endocrine system.
Clomipramine (CMI) is administered orally. Similar to other tricyclic antidepressants clomipramine is highly protein-bound approximately 97%, principally to albumin, and is independent of CMI concentration. Clomipramine is well distributed into CSF and the brain. Clomipramine may cross the placenta and is distributed into breast milk. Metabolism of clomipramine takes place in the liver, primarily via CYP2D6 and also to some extent by CYP1A2. Metabolism produces desmethylclomipramine (DMI), the major active metabolite, and several other compounds. DMI also distributes into CSF, with a mean CSF/plasma ratio of 2.6. Increasing doses of clomipramine result in pharmacokinetic values that suggest non-linear kinetics. Evidence that the steady-state concentration and AUC (exposure) for CMI and DMI may increase disproportionately with increasing oral doses suggests that the metabolism of CMI and DMI may be capacity limited. DMI also distributes into CSF, with a mean CSF/plasma ratio of 2.6. After a 25 mg radiolabeled dose of CMI in 2 subjects, 60% and 51%, respectively, of the dose were recovered in the urine and 32% and 24%, respectively, in feces. In the same study, the combined urinary recoveries of CMI and DMI were only about 0.8% to 1.3% of the dose administered. After a 150 mg dose, the half-life of CMI ranges from 19 hours to 37 hours (mean, 32 hours) and that of DMI ranges from 54 hours to 77 hours (mean, 69 hours). Steady-state levels after multiple dosing are typically reached within 7 to 14 days for CMI. Plasma concentrations of the metabolite exceed the parent drug on multiple dosing. After multiple dosing with 150 mg/day, the accumulation factor for CMI is approximately 2.5 and for DMI is 4.6. Importantly, it may take 2 weeks or longer to achieve this extent of accumulation at constant dosing because of the relatively long elimination half-lives of CMI and DMI.
Affected cytochrome P450 (CYP450) enzymes and drug transporters: CYP2D6, CYP1A2
Clomipramine does not induce drug-metabolizing enzymes, as measured by antipyrine half-life. It is desirable to monitor plasma levels whenever an agent of the tricyclic antidepressant class, including clomipramine, is going to be co-administered with another drug known to be an inhibitor of CYP2D6 and/or CYP1A2. Drugs that inhibit these enzymes have been shown to reduce the metabolism of clomipramine. Co-administration of clomipramine with phenobarbital increases plasma concentrations of phenobarbital, suggesting an effect of clomipramine on phenobarbital metabolism or elimination.
-Route-Specific Pharmacokinetics
Oral Route
Clomipramine (CMI) is well absorbed from the GI tract; capsules are as bioavailable as oral solutions, and absorption is not significantly affected by food. In a dose proportionality study involving multiple clomipramine (CMI) doses, steady-state plasma concentrations (Css) and area-under-plasma-concentration-time curves (AUC) of CMI and CMI's major active metabolite, desmethylclomipramine (DMI), were not proportional to dose over the ranges evaluated, i.e., between 25 to 100 mg/day and between 25 to 150 mg/day, although Css and AUC are approximately linearly related to dose between 100 to 150 mg/day. The relationship between dose and CMI/DMI concentrations at higher daily doses has not been systematically assessed, but if there is significant dose dependency at doses above 150 mg/day, there is the potential for dramatically higher Css and AUC even for patients dosed within the recommended range. This may pose a potential risk to some patients. After a single 50 mg oral dose, maximum plasma concentrations (Cmax) of CMI occur within 2 to 6 hours (mean, 4.7 hours) and range from 56 ng/mL to 154 ng/mL (mean, 92 ng/mL). After multiple daily doses of 150 mg, steady-state maximum plasma concentrations range from 94 ng/mL to 339 ng/mL (mean, 218 ng/mL) for CMI and from 134 ng/mL to 532 ng/mL (mean, 274 ng/mL) for DMI. Additional information from a rising dose study of doses up to 250 mg suggests that DMI may exhibit nonlinear pharmacokinetics over the usual dosing range. At a dose of 200 mg of clomipramine, subjects who had a single blood sample taken approximately 9 to 22 hours, (median 16 hours), after the dose had plasma concentrations of up to 605 ng/mL for CMI, 781 ng/mL for DMI, and 1386 ng/mL for both.
-Special Populations
Hepatic Impairment
The manufacturer recommends that clomipramine be used with caution in patients with hepatic impairment; the effects of hepatic impairment on the pharmacokinetics or disposition of clomipramine have not been determined.
Renal Impairment
The manufacturer recommends that clomipramine be used with caution in patients with severe renal impairment; the effects of renal impairment on the pharmacokinetics or disposition of clomipramine have not been determined.
Pediatrics
Pediatric patients under 15 years of age had significantly lower plasma concentration/dose ratios of clomipramine, compared with adults.
Geriatric
Younger adult subjects (18 to 40 years of age) tolerated clomipramine better and had significantly lower steady-state plasma concentrations, compared with geriatric subjects over 65 years of age.
Other
Tobacco Smoking
Plasma concentrations of clomipramine were significantly lower in smokers than in nonsmokers.
CYP2D6 Poor Metabolizers (PMs)
The biochemical activity of the CYP2D6 is reduced in a subset of the Caucasian population (about 7% to 10% of Caucasians are so-called "poor metabolizers"); reliable estimates of the prevalence of reduced CYP2D6 isozyme activity among Asian, African and other populations are not yet available. Poor metabolizers have higher than expected plasma concentrations of tricyclic antidepressants (TCAs) when given usual doses. Depending on the fraction of drug metabolized by CYP2D6, the increase in plasma concentration may be small, or quite large (8-fold increase in plasma AUC of the TCA).