Chlophedianol; dexbrompheniramine is a combination of a cough suppressant and sedating antihistamine used to help relieve cough and symptoms of the common cold or allergic rhinitis. Chlophedianol is a centrally-acting non-opioid antitussive used to relieve dry, irritating coughs. In some countries, chlophedianol is known as clophedanol. Dexbrompheniramine is a sedating antihistamine (H1-blocker) of the alkylamine class that dries the nasal and sinus passages secondary to its anticholinergic activity, and treats histamine-mediated symptoms such as rhinorrhea and sneezing. Products are labeled for use in adult and pediatric patients 6 years and older.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
-May be given without regard to meals.
Oral Liquid Formulations
-For accurate dosage, measure each dose using a calibrated oral measuring device.
CNS depression manifested as drowsiness, sedation, or dizziness, can occur during therapy with propylamine antihistamines such as dexbrompheniramine in chlophedianol; dexbrompheniramine. Paradoxical CNS stimulation or excitability can also occur, although this is more likely to occur in children and is rare. Side effects reported with sedating antihistamines may include delirium, euphoria, insomnia, nervousness, palpitations, restlessness, tremor, and in severe cases, seizures. Other CNS effects reported with brompheniramine, and other antihistamines, include confusion, anxiety, tension, disturbed coordination, headache, lethargy, and muscular weakness. There is considerable individual patient response to sedative effects, so patients should be warned of the possible impairment of mental acuity. These side effects may disappear after a few days of treatment; although, if symptoms persist or are severe, a reduction in dosage or a change to another antihistamine may be necessary.
Dexbrompheniramine in chlophedianol; dexbrompheniramine possesses a moderate degree of anticholinergic activity. Dry mouth (xerostomia) is a more common effect of dexbrompheniramine. Anticholinergic effects that may occur include acute labyrinthitis, blurred vision, diplopia, dysuria (due to vesicle sphincter spasm), facial dyskinesia, impotence (erectile dysfunction), irritability, mydriasis, tinnitus, tremor, urinary retention, vertigo, visual impairment, and xerophthalmia. Geriatric patients are more susceptible to these adverse reactions, since endogenous cholinergic activity declines with age. Other adverse anticholinergic effects have been reported with antihistamines and include chills, hyperhidrosis, faintness, menstrual irregularity (e.g., early menses), nasal congestion, paresthesias, tightness of the chest, thickening of bronchial secretions, toxic psychosis, and wheezing.
Sedating antihistamines (H1-antagonists) such as dexbrompheniramine in chlophedianol; dexbrompheniramine can cause adverse gastrointestinal (GI) effects including upset stomach, constipation, gastric distress, abdominal cramping, pyrosis (heartburn), abdominal pain, anorexia, dyspepsia, nausea, and vomiting. Most of these effects are due to anticholinergic actions of dexbrompheniramine. Anticholinergic actions can increase the risk for constipation and slow GI motility. Some side effects of GI distress may be alleviated by administering with meals or milk.
Adverse cardiovascular responses to dexbrompheniramine and other antihistamines are likely to be associated with the anticholinergic properties of H1-antagonists or the quinidine-like anesthetic effects. These reactions are rare with usual use, but are typically seen in overdosage situations. These responses may include cardiac arrhythmia exacerbation (e.g., extrasystoles, AV block), ECG changes (e.g., widened QRS), palpitations, sinus tachycardia, angina, and/or circulatory collapse. Alpha-adrenergic blockade may lead to hypotension. Hypertension can also occur, but is usually not of clinical significance.
Polyuria and drug rash (unspecified) have been reported with brompheniramine use and might also occur with chlophedianol; dexbrompheniramine.
Avoid use of chlophedianol; dexbrompheniramine in patients who are hypersensitive to any of the drugs or product components.
Chlophedianol; dexbrompheniramine can cause drowsiness. Patients receiving this product should be advised to avoid driving or operating machinery until the effects of the drug are known. Additive CNS effects may occur during coadministration with other CNS depressants, including ethanol ingestion.
Use antihistamines, including dexbrompheniramine in chlophedianol; dexbrompheniramine, with caution in patients with asthma. The anticholinergic activity of H1-antagonists may result in thickened bronchial secretions in the respiratory tract thereby aggravating an acute asthmatic attack or some patients with chronic obstructive pulmonary disease (COPD). Although H1-antagonists should be avoided during an acute asthmatic attack up to and including status asthmaticus, these anticholinergic effects do not preclude the use of H1-antagonists in all asthmatic patients, particularly if thickened bronchial secretions is not a primary component of the illness. Antihistamines should be used under the direction of a physician in patients who have conditions such as asthma, emphysema or chronic bronchitis; self-medication is not recommended.
Chlophedianol; dexbrompheniramine should be used conservatively in patients with closed-angle glaucoma or increased intraocular pressure. An increase in intraocular pressure may occur from the anticholinergic actions of dexbrompheniramine, precipitating an acute attack of glaucoma. Elderly patients may be more susceptible to these anticholinergic effects, including possible precipitation of undiagnosed glaucoma. Other ocular effects resulting from the anticholinergic effects of dexbrompheniramine include dry eyes or blurred vision. This may be of significance in the elderly and wearers of contact lenses.
Chlophedianol; dexbrompheniramine should be used cautiously in certain conditions due to the anticholinergic effects of dexbrompheniramine. Dexbrompheniramine can increase the risk for urinary difficulties in at-risk patients. Patients more prone to urinary tract effects include those patients with prostatic hypertrophy and risks for bladder obstruction. The concomitant use of other anticholinergic drugs with chlophedianol; dexbrompheniramine may increase the risk of urinary retention. Although dexbrompheniramine has only moderate anticholinergic effects, a worsening of symptoms may be seen in patients with GI obstruction or ileus. Constipation may also worsen due to the anticholinergic effects, and the elderly may be more at risk for this side effect.
Chlophedianol; dexbrompheniramine should be used with caution in patients with significant hepatic disease. Dexbrompheniramine is extensively metabolized by the liver; therefore, the metabolism of dexbrompheniramine may be reduced in the presence of hepatic impairment. Data for chlophedianol are not available.
Caution is advised when using chlophedianol; dexbrompheniramine products as the anticholinergic effects of first-generation antihistamines may be significant and are additive with other anticholinergic medications, particularly in the geriatric adult.
Chlophedianol; dexbrompheniramine is an antihistamine and should be administered with caution in patients with a seizure disorder. Antihistamines such as dexbrompheniramine may rarely precipitate epileptiform seizures in patients with focal lesions of the cerebral cortex.
No well controlled trials are available regarding the use of chlophedianol or dexbrompheniramine during pregnancy; use of chlophedianol; dexbrompheniramine combination products during pregnancy is not recommended. Loratadine and oral cetirizine are acceptable antihistamine alternatives for colds or allergies based on their excellent safety data and recommendation in multiple guidelines for use during pregnancy. Non-pharmacologic methods (e.g., fluids, rest) are recommended to be tried first for symptomatic relief of rhinitis or allergies during pregnancy. Pregnant patients should see their health care professional for a proper diagnosis and for treatment recommendations.
Combination products containing chlophedianol; dexbrompheniramine should be used with caution during breast-feeding. Small, occasional doses of brompheniramine would not be expected to cause adverse effects in breastfed infants; insignificant amounts of dexbrompheniramine are secreted in the breast milk. Larger doses or more prolonged use may cause effects in the infant or decrease the milk supply. Side effects in breast-feeding infants may manifest as irritability, disturbed sleeping patterns, drowsiness, hyperexcitability, or excessive crying. Antihistamines can lower basal prolactin secretion and may interfere with the establishment of lactation. Consider treatment alternatives to chlophedianol; dexbrompheniramine. The British Society for Allergy and Clinical Immunology recommends loratadine or cetirizine at the lowest dose as preferred antihistamines in breast-feeding women because they are safer with only low levels found in breast milk.
Chlophedianol; dexbrompheniramine products are not recommended for use in infants and children less than 6 years of age. Due to the risk for serious adverse reactions, the FDA recommends against administration of over the counter (OTC) cough and cold products to infants and children younger than 2 years of age. When administering OTC medications to older pediatric patients, advise caregivers to read product labels carefully, use caution when administering multiple products to avoid duplication of ingredients, and use only measuring devices specifically designed for use with medications. Thoroughly assess each patient's use of similar products, both prescription and nonprescription, to avoid duplication of therapy and the potential for inadvertent overdose.
Use chlophedianol; dexbrompheniramine with caution in patients taking monoamine oxidase inhibitor therapy (MAOI therapy). Monoamine oxidase inhibitors (MAOIs) may prolong and intensify the anticholinergic effects of sedating antihistamines. The anticholinergic activity of MAOIs is minimal; however, anticholinergic effects sometimes occur. Some manufacturers recommend that first-generation sedating antihistamines not be used within 2 weeks of therapy with an MAOI; however, some expert reviews state to use caution, as evidence for clinically significant interactions is lacking.
For the temporary relief of cough, rhinorrhea, and other symptoms of the common cold or allergic rhinitis:
Oral dosage (oral solution with chlophedianol 12.5 mg and dexchlorpheniramine 1 mg per 5 mL; e.g., Chlo Hist):
Adults: 10 mL PO every 6 hours, not to exceed 4 doses (40 mL) in 24 hours.
Children and Adolescents 12 years and older: 10 mL PO every 6 hours, not to exceed 4 doses (40 mL) in 24 hours.
Children 6 to 11 years: 5 mL PO every 6 hours, not to exceed 4 doses (20 mL) in 24 hours.
Maximum Dosage Limits:
-Adults
Chlophedianol 100 mg/day PO; dexbrompheniramine 8 mg/day PO.
-Geriatric
Chlophedianol 100 mg/day PO; dexbrompheniramine 8 mg/day PO.
-Adolescents
Chlophedianol 100 mg/day PO; dexbrompheniramine 8 mg/day PO.
-Children
12 years and older: Chlophedianol 100 mg/day PO; dexbrompheniramine 8 mg/day PO.
6 to 11 years: Chlophedianol 50 mg/day PO; dexbrompheniramine 4 mg/day PO.
Less than 6 years: Safety and efficacy have not been established.
-Infants
Safety and efficacy have not been established.
-Neonates
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Since these drugs are metabolized by the liver, it may be prudent to initiate the dosage cautiously in patients with hepatic impairment. Data for this combination product in patients with hepatic disease are lacking.
Patients with Renal Impairment Dosing
Based on data for brompheniramine, it appears that no dosage adjustment for dexbrompheniramine is needed. Data in patients with renal impairment are lacking for chlophedianol and for this combination product.
Intermittent hemodialysis:
It appears that no supplemental dosage is needed.
*non-FDA-approved indication
Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Acetaminophen; Codeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Acetaminophen; Hydrocodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Acetaminophen; Oxycodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Alfentanil: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Alosetron: (Moderate) Alosetron, if combined with drugs that possess anticholinergic properties like sedating H1 blockers, may seriously worsen constipation, leading to events such as GI obstruction/impaction or paralytic ileus.
Alprazolam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Amantadine: (Moderate) Medications with significant anticholinergic activity may potentiate the anticholinergic effects of amantadine, and may increase the risk of antimuscarinic-related side effects. Additive drowsiness may also occur.
Amoxapine: (Moderate) Additive anticholinergic effects may be seen when amoxapine is used concomitantly with drugs are known to possess relatively significant antimuscarinic properties, including sedating H1-blockers. Antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature Additive sedation may also occur.
Amphetamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers (i.e., diphenhydramine). This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Amphetamine; Dextroamphetamine Salts: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers (i.e., diphenhydramine). This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Amphetamine; Dextroamphetamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers (i.e., diphenhydramine). This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Additive anticholinergic effects may be seen when drugs with anticholinergic properties, like sedating H1-blockers and orphenadrine, are used concomitantly. Adverse 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.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Carisoprodol is metabolized to meprobamate, a significant CNS depressant. Carisoprodol can cause additive CNS depression if used concomitantly with other CNS depressants. Additive effects of sedation and dizziness, which can impair the ability to undertake tasks requiring mental alertness, may occur if carisoprodol is taken with sedating H1-blockers. Utilize appropriate caution if carisoprodol is coadministered with another CNS depressant. (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Aspirin, ASA; Oxycodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Atropine: (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Atropine; Difenoxin: (Moderate) An enhanced CNS depressant effect may occur when diphenoxylate/difenoxin is combined with other CNS depressants. Diphenoxylate/difenoxin decreases GI motility. Other drugs that also decrease GI motility, such as sedating H1 blockers, may produce additive effects with diphenoxylate/difenoxin if used concomitantly. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Azelastine: (Major) Avoid concomitant use of azelastine and sedating H1-blockers due to risk for additive CNS depression.
Azelastine; Fluticasone: (Major) Avoid concomitant use of azelastine and sedating H1-blockers due to risk for additive CNS depression.
Baclofen: (Moderate) An enhanced CNS depressant effect may occur when sedating H1-blockers are combined with other CNS depressants including skeletal muscle relaxants, such as baclofen.
Belladonna; Opium: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and belladonna use. Concomitant use may result in additive anticholinergic adverse effects.
Benzhydrocodone; Acetaminophen: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Benzodiazepines: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Benzphetamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Benztropine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and benztropine use. Concomitant use may result in additive anticholinergic adverse effects.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Butalbital; Aspirin; Caffeine; Codeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Butorphanol: (Moderate) Concomitant use of butorphanol with sedating H1-blockers can potentiate the effects of butorphanol on CNS and/or respiratory depression. Use together with caution. If a CNS depressant needs to be used with butorphanol, use the smallest effective dose and the longest dosing frequency of butorphanol.
Cannabidiol: (Moderate) Monitor for excessive sedation and somnolence during coadministration of cannabidiol and sedating H1-blockers. CNS depressants can potentiate the effects of cannabidiol.
Capsaicin; Metaxalone: (Moderate) Concomitant administration of metaxalone with other CNS depressants can potentiate the sedative effects of either agent.
Carbidopa; Levodopa; Entacapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including sedating H1-blockers, 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.
Carisoprodol: (Moderate) Carisoprodol is metabolized to meprobamate, a significant CNS depressant. Carisoprodol can cause additive CNS depression if used concomitantly with other CNS depressants. Additive effects of sedation and dizziness, which can impair the ability to undertake tasks requiring mental alertness, may occur if carisoprodol is taken with sedating H1-blockers. Utilize appropriate caution if carisoprodol is coadministered with another CNS depressant.
Celecoxib; Tramadol: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Cenobamate: (Moderate) Monitor for excessive sedation and somnolence during coadministration of cenobamate and sedating H1-blockers. Concurrent use may result in additive CNS depression.
Cetirizine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and sedating H1-blockers. Concomitant use may result in additive CNS depression or anticholinergic effects.
Cetirizine; Pseudoephedrine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and sedating H1-blockers. Concomitant use may result in additive CNS depression or anticholinergic effects.
Chlordiazepoxide: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Chlordiazepoxide; Amitriptyline: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Chlordiazepoxide; Clidinium: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Chlorpheniramine; Codeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Chlorpheniramine; Hydrocodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Chlorpromazine: (Moderate) Additive anticholinergic and sedative effects may be seen when chlorpromazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Chlorzoxazone: (Moderate) Additive CNS depression is possible if chlorzoxazone is used concomitantly with other CNS depressants including sedating H1-blockers. Additive effects of sedation and dizziness can occur, which can impair the ability to undertake tasks requiring mental alertness. Dosage adjustments of one or both medications may be necessary.
Clobazam: (Moderate) Clobazam, a benzodiazepine, may cause drowsiness or other CNS effects. Additive drowsiness may occur when clobazam is combined with CNS depressants such as sedating H1-blockers. In addition, caution is recommended when administering clobazam with medications extensively metabolized by CYP2D6 such as diphenhydramine because clobazam has been shown to inhibit CYP2D6 in vivo and may increase concentrations of drugs metabolized by this enzyme.
Clonazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Clorazepate: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Clozapine: (Moderate) Clozapine exhibits clinically significant anticholinergic effects and sedation that may be additive with other medications that may cause anticholinergic effects and sedation, including antihistamines such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines and to avoid tasks requiring mental alertness until they are aware of the effects of the combination.
Codeine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Codeine; Guaifenesin: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Codeine; Phenylephrine; Promethazine: (Moderate) Additive anticholinergic and sedative effects may be seen when promethazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines. (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Codeine; Promethazine: (Moderate) Additive anticholinergic and sedative effects may be seen when promethazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines. (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
COMT inhibitors: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including sedating H1-blockers, 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.
Dantrolene: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect (e.g., drowsiness) may occur when dantrolene is combined with other CNS depressants.
Daratumumab; Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Desloratadine: (Minor) Although desloratadine is considered a 'non-sedating' antihistamine, dose-related sedation has been noted. For this reason, it would be prudent to monitor for drowsiness during concurrent use of desloratadine with CNS depressants such as other H1-blockers.
Desloratadine; Pseudoephedrine: (Minor) Although desloratadine is considered a 'non-sedating' antihistamine, dose-related sedation has been noted. For this reason, it would be prudent to monitor for drowsiness during concurrent use of desloratadine with CNS depressants such as other H1-blockers.
Dexmedetomidine: (Moderate) Consider a dosage reduction for dexmedetomidine or the sedating antihistamine during concomitant use due to the risk of additive CNS effects.
Dextroamphetamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers (i.e., diphenhydramine). This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Diazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Dicyclomine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and dicyclomine use. Concomitant use may result in additive anticholinergic adverse effects.
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.
Diphenoxylate; Atropine: (Moderate) An enhanced CNS depressant effect may occur when diphenoxylate/difenoxin is combined with other CNS depressants. Diphenoxylate/difenoxin decreases GI motility. Other drugs that also decrease GI motility, such as sedating H1 blockers, may produce additive effects with diphenoxylate/difenoxin if used concomitantly. (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and atropine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Dronabinol: (Moderate) Use caution if coadministration of dronabinol with antihistamines is necessary. Concurrent use of dronabinol, THC with antihistamines may result in additive drowsiness, hypertension, tachycardia, and possibly cardiotoxicity.
Efgartigimod Alfa; Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Entacapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including sedating H1-blockers, 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.
Estazolam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Eszopiclone: (Moderate) A reduction in the dose of eszopiclone and concomitantly administered CNS depressants, such as sedating H1-blockers, 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.
Ethanol: (Major) Advise patients to avoid alcohol consumption while taking CNS depressants. Alcohol consumption may result in additive CNS depression.
Etomidate: (Minor) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect may occur when they are combined with general anesthetics.
Fenfluramine: (Moderate) Monitor for excessive sedation and somnolence during coadministration of fenfluramine and dexbrompheniramine. Concurrent use may result in additive CNS depression.
Fentanyl: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Flavoxate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and flavoxate use. Concomitant use may result in additive anticholinergic adverse effects.
Flibanserin: (Moderate) The concomitant use of flibanserin with CNS depressants, such as sedating H1-blockers, may increase the risk of CNS depression (e.g., dizziness, somnolence) compared to the use of flibanserin alone. Patients should avoid activities requiring full alertness (e.g., operating machinery or driving) until at least 6 hours after each dose and until they know how flibanserin affects them.
Fluphenazine: (Moderate) Additive sedative effects may be seen when fluphenazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Flurazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Food: (Major) Advise patients to avoid cannabis use while taking CNS depressants due to the risk for additive CNS depression and potential for other cognitive adverse reactions.
Gabapentin: (Moderate) Monitor for excessive sedation and somnolence during coadministration of dexbrompheniramine and gabapentin. Concurrent use may result in additive CNS depression.
Galantamine: (Moderate) Concurrent use of sedating H1-blockers and galantamine should be avoided if possible. Galantamine inhibits acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, and improves the availability of acetylcholine. Sedating H1-blockers may exhibit significant anticholinergic activity, thereby interfering with the therapeutic effect of galantamine.
Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker 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 sedating H1-blocker and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Heparin: (Minor) Antihistamines may partially counteract the anticoagulant actions of heparin, according to the product labels. However, this interaction is not likely of clinical significance since heparin therapy is adjusted to the partial thromboplastin time (aPTT) and other clinical parameters of the patient.
Homatropine; Hydrocodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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. (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and homatropine use. Concomitant use may result in additive anticholinergic adverse effects.
Hyaluronidase, Recombinant; Immune Globulin: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Hydrocodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Hydrocodone; Ibuprofen: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Hydromorphone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Hyoscyamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Ibuprofen; Oxycodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Indacaterol; Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Isocarboxazid: (Contraindicated) Concomitant use of monoamine oxidase inhibitors and sedating H1-blockers is contraindicated due to increased anticholinergic effects.
Ketamine: (Minor) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect may occur when they are combined with general anesthetics.
Lasmiditan: (Moderate) Monitor for excessive sedation and somnolence during coadministration of lasmiditan and sedating H1-blockers. Concurrent use may result in additive CNS depression.
Lemborexant: (Moderate) Monitor for excessive sedation and somnolence during coadministration of lemborexant and sedating antihistamines (H1-blockers). Dosage adjustments of lemborexant and sedating H1-blockers 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. Patients should generally avoid nonprescription antihistamine products that are marketed as sleep-aids concurrently with lemborexant.
Levocetirizine: (Moderate) Monitor for unusual drowsiness and sedation, urinary retention, and reduced gastric motility during coadministration of cetirizine and sedating H1-blockers. Concomitant use may result in additive CNS depression or anticholinergic effects.
Levorphanol: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Loratadine: (Minor) Although loratadine is considered a 'non-sedating' antihistamine, dose-related sedation has been noted. For this reason, it would be prudent to monitor for drowsiness during concurrent use of loratadine with CNS depressants such as other H1-blockers.
Loratadine; Pseudoephedrine: (Minor) Although loratadine is considered a 'non-sedating' antihistamine, dose-related sedation has been noted. For this reason, it would be prudent to monitor for drowsiness during concurrent use of loratadine with CNS depressants such as other H1-blockers.
Lorazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Loxapine: (Moderate) Sedating H1-blockers are associated with anticholinergic effects and sedation; therefore, additive effects may be seen during concurrent use with other drugs having anticholinergic activity and CNS depressant properties such as traditional antipsychotic agents, including loxapine. 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.
Lumateperone: (Moderate) Monitor for excessive sedation and somnolence during coadministration of lumateperone and dexbrompheniramine. Concurrent use may result in additive CNS depression.
Lurasidone: (Moderate) Due to the CNS effects of lurasidone, caution should be used when lurasidone is given in combination with other centrally acting medications. Sedating H1-blockers are associated with sedation; therefore, additive effects may be seen during concurrent use with other drugs having CNS depressant properties such as antipsychotics. Additive drowsiness or other CNS effects may occur.
Melatonin: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of melatonin and sedating H1-blockers due to the risk for additive CNS depression.
Meperidine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Meprobamate: (Moderate) The CNS-depressant effects of meprobamate can be potentiated with concomitant administration of other drugs known to cause CNS depression including sedating H1-blockers.
Metaxalone: (Moderate) Concomitant administration of metaxalone with other CNS depressants can potentiate the sedative effects of either agent.
Methadone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Methamphetamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine. Coadminister with caution and monitor for altered response to drug therapy.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and hyoscyamine use. Concomitant use may result in additive anticholinergic adverse effects.
Methocarbamol: (Moderate) Methocarbamol may cause additive CNS depression if used concomitantly with other CNS depressants such as sedating H1-blockers. Combination therapy can cause additive effects of sedation and dizziness, which can impair the patient's ability to undertake tasks requiring mental alertness. Dosage adjustments of either or both medications may be necessary.
Methscopolamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and methscopolamine use. Concomitant use may result in additive anticholinergic adverse effects.
Metoclopramide: (Minor) Combined use of metoclopramide and other CNS depressants, such as anxiolytics, sedatives, and hypnotics, can increase possible sedation.
Metyrosine: (Moderate) The concomitant administration of metyrosine with sedating H1-blockers can result in additive sedative effects.
Midazolam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
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 sedating H1-blockers. Caution should be exercised when using these agents concurrently.
Mirtazapine: (Moderate) Consistent with the CNS depressant effects of mirtazapine, additive effects may occur with other CNS depressants such as dexbrompheniramine. Mirtazapine should be administered cautiously with such agents because the CNS effects on cognitive performance and motor skills can be additive.
Mitotane: (Moderate) Mitotane can cause sedation, lethargy, vertigo, and other CNS side effects. Concomitant administration of mitotane and CNS depressants, including sedating h1-blockers, may cause additive CNS effects.
Molindone: (Moderate) An enhanced CNS depressant effect may occur when sedating h1-blockers are combined with other CNS depressants including molindone.
Monoamine oxidase inhibitors: (Contraindicated) Concomitant use of monoamine oxidase inhibitors and sedating H1-blockers is contraindicated due to increased anticholinergic effects.
Morphine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Morphine; Naltrexone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Nabilone: (Moderate) Concomitant use of nabilone with other CNS depressants, such as sedating H1-blockers, can potentiate the effects of nabilone on respiratory depression.
Nalbuphine: (Moderate) Concomitant use of nalbuphine with other CNS depressants, such as sedating H1-blockers, can potentiate the effects of nalbuphine on respiratory depression, CNS depression, and sedation.
Nefazodone: (Moderate) An enhanced CNS depressant effect may occur when sedating H1-blockers are combined with other CNS depressants including nefazodone.
Neostigmine; Glycopyrrolate: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and glycopyrrolate use. Concomitant use may result in additive anticholinergic adverse effects.
Oliceridine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Opiate Agonists: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Opicapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including sedating H1-blockers, 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.
Orphenadrine: (Moderate) Additive anticholinergic effects may be seen when drugs with anticholinergic properties, like sedating H1-blockers and orphenadrine, are used concomitantly. Adverse 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.
Oxazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Oxybutynin: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and oxybutynin use. Concomitant use may result in additive anticholinergic adverse effects.
Oxycodone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Oxymorphone: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Paroxetine: (Moderate) Of the selective serotonin reuptake inhibiting antidepressants (SSRIs), paroxetine is considered the most anticholinergic. Additive anticholinergic effects may be seen when paroxetine is used with antihistamines having anticholinergic properties such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Pentazocine; Naloxone: (Moderate) Use pentazocine with caution in any patient receiving medication with CNS depressant and/or anticholinergic activity. Coadministration of pentazocine with sedating H1-blockers may result in additive respiratory and CNS depression and anticholinergic effects, such as urinary retention and constipation.
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 sedating H1-blockers.
Perphenazine: (Moderate) Additive anticholinergic and sedative effects may be seen when perphenazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Perphenazine; Amitriptyline: (Moderate) Additive anticholinergic and sedative effects may be seen when perphenazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Pertuzumab; Trastuzumab; Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Phenelzine: (Contraindicated) Concomitant use of monoamine oxidase inhibitors and sedating H1-blockers is contraindicated due to increased anticholinergic effects.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker 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 sedating H1-blocker 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 sedating H1-blocker and scopolamine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Pitolisant: (Major) Avoid coadministration of pitolisant with dexbrompheniramine as the effect of pitolisant may be decreased. Pitolisant increases histamine concentrations in the brain; therefore, H1-receptor antagonists like dexbrompheniramine, may reduce pitolisant efficacy.
Pramipexole: (Moderate) Concomitant use of pramipexole with other CNS depressants, such as sedating H1-blockers, can potentiate the sedation effects of pramipexole.
Pregabalin: (Moderate) Monitor for excessive sedation and somnolence during coadministration of dexbrompheniramine and pregabalin. Concurrent use may result in additive CNS depression.
Procarbazine: (Moderate) Use procarbazine and sedating H1-blockers together with caution; additive central nervous system depression may occur.
Prochlorperazine: (Moderate) Additive anticholinergic and sedative effects may be seen when prochlorperazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Promethazine: (Moderate) Additive anticholinergic and sedative effects may be seen when promethazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Promethazine; Dextromethorphan: (Moderate) Additive anticholinergic and sedative effects may be seen when promethazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Promethazine; Phenylephrine: (Moderate) Additive anticholinergic and sedative effects may be seen when promethazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Propantheline: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and propantheline use. Concomitant use may result in additive anticholinergic adverse effects.
Propofol: (Minor) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect may occur when they are combined with general anesthetics.
Quazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Ramelteon: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect may occur when it is combined with other CNS depressants including anxiolytics, sedatives, and hypnotics, such as ramelteon.
Rasagiline: (Moderate) Concurrent use of monoamine oxidase inhibitors (MAOIs) and sedating H1-blockers (sedating antihistamines) may result in additive sedation, anticholinergic effects, or hypotensive reactions. Rasagiline may be less likely to produce these interactions than other MAOIs, due to MAO-B selectivity. However, consider alternatives therapy to antihistamines where possible. If alternative combinations are not available, these medications may be used together with close monitoring. Many non-prescription products for coughs, colds, allergy, hay fever or insomnia contain sedating antihistamines. Patients receiving rasagiline should be counseled that it is essential to consult their healthcare provider or pharmacist prior to the use of any non-prescription products. Patients should also be advised against driving or engaging in other activities requiring mental alertness until they know how this combination affects them.
Remifentanil: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Remimazolam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Rituximab; Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Rivastigmine: (Moderate) Concurrent use of sedating H1-blockers and rivastigmine should be avoided if possible. Rivastigmine inhibits acetylcholinesterase, the enzyme responsible for the degradation of acetylcholine, and improves the availability of acetylcholine. Sedating H1-blockers may exhibit significant anticholinergic activity, thereby interfering with the therapeutic effect of rivastigmine.
Ropinirole: (Moderate) Concomitant use of ropinirole with other CNS depressants, such as sedating H1-blockers, can potentiate the sedation effects of ropinirole.
Safinamide: (Moderate) Dopaminergic medications, including safinamide, may cause a sudden onset of somnolence which sometimes has resulted in motor vehicle accidents. Patients may not perceive warning signs, such as excessive drowsiness, or they may report feeling alert immediately prior to the event. Because of possible additive effects, advise patients about the potential for increased somnolence during concurrent use of other sedating medications, such as sedating H1-blockers.
Scopolamine: (Moderate) Monitor for unusual drowsiness or excess sedation and for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and scopolamine use. Concomitant use may result in additive CNS depression or anticholinergic adverse effects.
Selegiline: (Moderate) Monitor for excessive sedation and somnolence during coadministration of selegiline and dexbrompheniramine. Concurrent use may result in additive CNS depression.
Sincalide: (Moderate) Sincalide-induced gallbladder ejection fraction may be affected by concurrent medications, including H1-blockers. False study results are possible; thorough patient history is important in the interpretation of procedure results.
Sodium Iodide: (Moderate) Antihistamines may alter sodium iodide I-131 pharmacokinetics and dynamics for up to 1 week after administration. In addition, medications that decrease salivation increase the time of radiation exposure to salivary glands. Consider discontinuing sedating H1-blockers prior to sodium iodide I-131 administration.
Sufentanil: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Suvorexant: (Moderate) Monitor for excessive sedation and somnolence during coadministration of suvorexant and sedating antihistamines (H1-blockers). Dosage adjustments of suvorexant and sedating H1-blockers may be necessary when administered together because of potentially additive CNS effects. The risk of next-day impairment, including impaired driving, is increased if suvorexant is taken with other CNS depressants. Patients should generally avoid nonprescription antihistamine products that are marketed as sleep-aids concurrently with suvorexant.
Tapentadol: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Tasimelteon: (Moderate) Because sedating H1-blockers cause sedation, an enhanced CNS depressant effect may occur when it is combined with other CNS depressants including anxiolytics, sedatives, and hypnotics, such as tasimelteon.
Temazepam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Thalidomide: (Major) Avoid the concomitant use of thalidomide with opiate agonists; antihistamines; antipsychotics; anxiolytics, sedatives, and hypnotics; and other central nervous system depressants due to the potential for additive sedative effects.
Thioridazine: (Moderate) Additive anticholinergic and sedative effects may be seen when thioridazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Thiothixene: (Moderate) Additive anticholinergic effects may be seen when antipsychotics, such as thiothixene, are used concomitantly with other drugs such as sedating H1-blockers. Additive drowsiness or other CNS effects may also occur.
Tolcapone: (Moderate) COMT inhibitors should be given cautiously with other agents that cause CNS depression, including sedating H1-blockers, 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.
Tramadol: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Tramadol; Acetaminophen: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine 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.
Tranylcypromine: (Contraindicated) Concomitant use of monoamine oxidase inhibitors and sedating H1-blockers is contraindicated due to increased anticholinergic effects.
Trastuzumab; Hyaluronidase: (Minor) H1-blockers (antihistamines), when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients receiving these medications may require larger amounts of hyaluronidase for equivalent dispersing effect.
Triazolam: (Moderate) Coadministration can potentiate the CNS effects (e.g., increased sedation or respiratory depression) of either agent. Use caution with this combination.
Trifluoperazine: (Moderate) Additive anticholinergic and sedative effects may be seen when trifluoperazine is used with first generation antihistamines, such as dexbrompheniramine. Patients should be informed to read non-prescription cough and cold product labels carefully for additional interacting antihistamines.
Trihexyphenidyl: (Moderate) Monitor for signs or symptoms of anticholinergic toxicity during concomitant sedating H1-blocker and trihexyphenidyl use. Concomitant use may result in additive anticholinergic adverse effects.
Trimethobenzamide: (Moderate) The concurrent use of trimethobenzamide with other medications that cause CNS depression, like the sedating h1-blockers, may potentiate the effects of either trimethobenzamide or the sedating h1-blocker.
Trospium: (Moderate) Additive anticholinergic effects may be seen when trospium is used concomitantly with drugs that are known to possess relatively significant antimuscarinic properties, including sedating H1-blockers. Clinicians should note that additive antimuscarinic effects may be seen not only on GI smooth muscle, but also on bladder function 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.
Vigabatrin: (Moderate) Vigabatrin may cause somnolence and fatigue. Drugs that can cause CNS depression, if used concomitantly with vigabatrin, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when vigabatrin is given with sedating H1-blockers.
Vilazodone: (Moderate) Due to the CNS effects of vilazodone, caution should be used when vilazodone is given in combination with other centrally acting medications such as anxiolytics, sedatives, and hypnotics. Also, Cyproheptadine is an antagonist of serotonin in the CNS, a property which may oppose some of the pharmacologic effects of vilazodone. Cyproheptadine has been used for the management of orgasm dysfunction caused by the serotonergic antidepressants and for the adjunctive treatment of serotonin syndrome; however, a reversal of antidepressant effects may occur when cyproheptadine is given in a routine manner along with the antidepressant. Clinically, cyproheptadine reportedly has interfered with the antidepressant and anti-bulimia actions of fluoxetine, but more data are needed to confirm a direct drug-drug interaction.
Zaleplon: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of sedating H1-blockers and zaleplon due to the risk for additive CNS depression and next-day psychomotor impairment; dose adjustments may be necessary.
Ziconotide: (Moderate) Sedating H1-blockers are CNS depressant medications that may increase drowsiness, dizziness, and confusion that are associated with ziconotide.
Zolpidem: (Moderate) Monitor for unusual drowsiness and sedation during coadministration of sedating H1-blockers 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.
Zuranolone: (Major) Avoid the use of multiple sedating agents due to the risk for additive CNS depression. If use is necessary, consider a downward dosage adjustment of either or both medications, especially in patients with additional risk factors for sedation-related harm.
Chlophedianol; dexbrompheniramine combination products provide antitussive and antihistaminic properties for the temporary relief of cough and other symptoms associated with the common cold.
-Chlophedianol: Chlophedianol suppresses the cough reflex by a direct effect on the cough center in the medulla of the brain. Chlophedianol may also have local anesthetic and anticholinergic effects.
-Dexbrompheniramine: Dexbrompheniramine is the pharmacologically active (S)-(+)-enantiomer of brompheniramine and is a first-generation sedating antihistamine (H1-blocker). Dexbrompheniramine is an antagonist at H1-receptors. Dexbrompheniramine does not prevent the release of histamine, as do cromolyn and nedocromil, but rather competes with free histamine for binding at H1-receptor sites. Dexbrompheniramine competitively antagonizes the effects of histamine on H1-receptors in the GI tract, uterus, large blood vessels, and bronchial smooth muscle. Blockade of H1-receptors suppresses the edema, flare, and pruritus that results from histaminic activity. H1-blockers also possess anticholinergic properties in varying degrees. The anticholinergic activity of propylamine derivatives such as dexbrompheniramine is moderate. This anticholinergic action appears to be due to a central antimuscarinic effect. Sedative effects from dexbrompheniramine result from antagonism at central histaminergic receptors. Chronic administration may lead to some degree of tolerance, but the sedative effects may also be reduced.
Chlophedianol; dexbrompheniramine combination products are administered orally as a liquid.
-Chlophedianol: Metabolized in the liver and eliminated by the kidneys.
-Dexbrompheniramine: Pharmacokinetic data for dexbrompheniramine, the primary active dextrorotatory isomer of brompheniramine, are not specifically available but are likely similar to brompheniramine. Brompheniramine pharmacokinetics are primarily presented here. Brompheniramine distribution into human body tissues and fluids appears to be wide, but has not been fully characterized. Brompheniramine undergoes N-dealkylation to form monodesmethylbrompheniramine and didesmethylbrompheniramine. The drug is also metabolized to the propionic acid derivative, which is partially conjugated with glycine, and to other unidentified metabolites. The half-life is approximately 22 hours.
-Route-Specific Pharmacokinetics
Oral Route
-Chlophedianol: After absorption from the GI tract, time to peak effect may be longer than other central-acting antitussive agents.
-Dexbrompheniramine: Dexbrompheniramine is well absorbed from the GI tract following oral administration. The onset of action is about 30 to 60 minutes with a maximum therapeutic effect seen at 6 hours, although the duration can range between 4 and 8 hours.