Bethanechol is a synthetic parasympathomimetic indicated for the treatment of urinary retention associated with neurogenic bladder. Bethanechol is currently used less frequently due to the availability of more effective agents. It is an old drug which has also been used to stimulate GI motility. However, the availability of metoclopramide and other prokinetic agents has decreased the use of bethanechol as a stimulant of GI motility. Bethanechol occasionally is used to increase lower esophageal pressure in the treatment of gastric reflux; however, its use is limited by cholinergic side effects such as diarrhea and abdominal cramping. Bethanechol has also been used to offset some of the bothersome anticholinergic reactions to tricyclic antidepressants. Bethanechol has negligible cardiovascular effects at therapeutic doses. Bethanechol was approved by the FDA in 1948.
General Administration Information
For storage information, see the specific product information within the How Supplied section.
Route-Specific Administration
Oral Administration
-Administer bethanechol on an empty stomach (i.e., 1 hour before or 2 hours after a meal) to minimize nausea and vomiting.
Injectable Administration
-Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
Subcutaneous Administration:
-Bethanechol injection is for subcutaneous injection only. Do NOT administer intravenously or intramuscularly; serious adverse effects may occur.
-Inject subcutaneously taking care not to inject intradermally.
-No dilution necessary.
-After subcutaneous administration, the patient should be observed for 30 minutes to 1 hour for possible severe reactions, and a syringe containing a dose of atropine should be immediately available during this period.
Bethanechol can produce abdominal pain or cramps, colicky pain, belching, hypersalivation, diarrhea, flatulence, nausea, vomiting, and borborygmi. These reactions result from increased tone and peristaltic activity in the stomach and intestines. Administer bethanechol on an empty stomach (i.e., 1 hour before or 2 hours after a meal) to minimize nausea and vomiting.
Flushing and warmth of the skin, particularly about the face, and diaphoresis, are side effects associate with the use of bethanechol.
Cholinergic agonists such as bethanechol have the potential to cause bronchospasm or wheezing and should generally not be used in patients with asthma.
Ophthalmic adverse effects associated with bethanechol use are secondary to cholinergic stimulation and include miosis and lacrimation.
Urinary urgency and increased urinary frequency are expected results of the treatment for urinary retention with bethanechol.
Cardiovascular adverse effects associated with bethanechol use include a mild blood pressure decrease with reflex sinus tachycardia. Vasomotor response has also been reported.
Bethanechol may induce dizziness or potential for syncope, headache, seizures, and malaise.
Bethanechol use is contraindicated when the strength or integrity of the gastrointestinal or bladder wall is questionable. Increased muscular activity of the GI tract or bladder may prove harmful, worsening the underlying condition and risking rupture or perforation. Conditions that contraindicate bethanechol use include: GI obstruction (ileus) and bladder obstruction or urinary tract obstruction. Bethanechol is contraindicated in patients with inflammatory bowel disease, peritonitis, marked vagotonia, or who have undergone recent gastrointestinal or bladder surgery. Increased stimulation of gastric acid also contraindicates bethanechol use in peptic ulcer disease.
Bethanechol use is contraindicated in patients with pronounced bradycardia, pronounced hypotension, or coronary artery disease. Bethanechol can cause orthostatic hypotension, specifically after subcutaneous administration, and should be used with caution in patients at risk for syncope. Bethanechol should never be given by intramuscular injections or intravenous administration. Administration by either of these routes can precipitate cholinergic over-stimulation, causing circulatory collapse, sudden hypotension, abdominal cramps, bloody diarrhea, shock, or sudden cardiac arrest. A more precipitous drop in blood pressure can be seen in patients with hypertension. Administration by the oral or subcutaneous route can have a mild negative chronotropic effect. Due to potential for orthostatic hypotension, patients may be warned to avoid driving or operating machinery until the effects of bethanechol are known.
Bethanechol is contraindicated in patients with asthma; Bethanechol should also be avoided in chronic obstructive pulmonary disease (COPD) because cholinergic stimulation constricts the airways.
Bethanechol is also contraindicated in patients with hyperthyroidism, seizures or seizure disorder, and parkinsonism because it can exacerbate these conditions. Cholinergic drugs may precipitate atrial fibrillation in patients with hyperthyroidism.
The manufacturer states that the safe and effective use of bethanechol in children has not been established. However, bethanechol has been used off-label to treat children with urinary retention or certain gastrointestinal (GI) conditions.
Bethanechol chloride should be given during pregnancy only if clearly needed. It is not known whether bethanechol can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Bethanechol has not been evaluated in animal reproductive studies.
It is not known if bethanechol is excreted into breast milk. Because of the potential for serious adverse reactions from bethanechol chloride in nursing infants, a decision should be made whether to discontinue breast-feeding or to discontinue bethanechol, taking into account the importance of the drug to the mother.
The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents (e.g., geriatric adults) of long-term care facilities (LTCFs). According to the OBRA guidelines, assessment of the underlying causes and identification of the type/category of urinary incontinence needs to be documented prior to or soon after the time of initiating treatment with a urinary incontinence medication. These medications have specific and limited indications based on the cause and categorization of incontinence. Patients should be assessed periodically for medication effects on urinary incontinence as well as lower urinary tract symptoms and treatment tolerability. Adverse consequences of bethanechol include hypotension, increased sweating and salivation, headache, cramps, diarrhea, nausea, vomiting, and worsening of asthma.
For treatment of atonic neurogenic bladder or acute postoperative and postpartum non-obstructive urinary retention:
Oral dosage:
Adults: 5 to 10 mg PO every hour, initially, until satisfactory response occurs or a maximum of 50 mg has been given. Usual dose: 10 to 50 mg PO 3 to 4 times daily.
For the treatment of gastroesophageal reflux disease (GERD)* by increasing lower esophageal pressure:
Oral dosage:
Adults: 10-25 mg PO 4 times per day, after meals and at bedtime.
Children: 0.1-0.2 mg/kg PO 4 times per day (given 0.5-1 hour before each meal), or 3 mg/m2 PO every 8 hours.
For the treatment of gastric atony* or adynamic ileus*:
Oral dosage:
Adults: 10-20 mg PO 3-4 times per day before meals in cases of incomplete retention.
Subcutaneous dosage:
Adults: 10-20 mg subcutaneous 3-4 times per day if retention is complete and nothing enters the duodenum.
For treating disabling anticholinergic side effects 'anticholinergic syndrome' from medications such as tricyclic antidepressants*:
Oral dosage:
Adults: A dosage of 25 mg PO 3 times per day has been used.
Maximum Dosage Limits:
-Adults
200 mg/day PO or 40 mg/day SC (single maximum dose: 50 mg PO or 10 mg SC).
-Elderly
200 mg/day PO or 40 mg/day SC (single maximum dose: 50 mg PO or 10 mg SC).
-Adolescents
Safety and efficacy have not been established.
-Children
Safety and efficacy have not been established.
Patients with Hepatic Impairment Dosing
Specific guidelines for dosage adjustments in hepatic impairment are not available; the metabolic disposition of bethanechol is unknown.
Patients with Renal Impairment Dosing
No dosage adjustment needed.
*non-FDA-approved indication
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Diphenhydramine: (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Hydrocodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Acetaminophen; Oxycodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Acetaminophen; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acetaminophen; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Acrivastine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Alfentanil: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Alosetron: (Moderate) Pharmacodynamic interactions between alosetron and drugs that enhance peristalsis are theoretically possible, based on opposing pharmacologic outcomes. It may be wise to avoid use of bethanechol during alosetron treatment. Although these potential interactions have not been studied, bethanechol might negate the effect of alosetron.
Amitriptyline: (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.
Amoxapine: (Major) Amoxapine may antagonize some of the effects of parasympathomimetics. However, bethanechol has occasionally been used therapeutically to offset some of the adverse antimuscarinic effects of cyclic antidepressants. Due to their anticholinergic actions, some cyclic antidepressants, such as amoxapine, may potentially antagonize the therapeutic actions of cholinergic agonists.
Amphetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Amphetamine; Dextroamphetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Anticholinergics: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Articaine; Epinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Aspirin, ASA; Oxycodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Atropine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Atropine; Difenoxin: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa. (Moderate) Pharmacodynamic interactions between antidiarrheals and drugs that enhance peristalsis are theoretically possible. It is wise to avoid use of antidiarrheals in patients who require bethanechol.
Belladonna; Opium: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa. (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Benzhydrocodone; Acetaminophen: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Benzphetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Benztropine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Bismuth Subsalicylate: (Moderate) Pharmacodynamic interactions between loperamide and drugs that enhance peristalsis are theoretically possible. It is wise to avoid use loperamide in patients who require bethanechol.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Pharmacodynamic interactions between loperamide and drugs that enhance peristalsis are theoretically possible. It is wise to avoid use loperamide in patients who require bethanechol.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Brompheniramine; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Brompheniramine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Budesonide; Glycopyrrolate; Formoterol: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Bupivacaine; Epinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Bupropion: (Moderate) Bupropion exhibits moderate anticholinergic properties. Avoid co-use when possible since the effects of bethanechol, a cholinergic agonist, may be diminished. If co-use is necessary, monitor for the intended clinical response.
Bupropion; Naltrexone: (Moderate) Bupropion exhibits moderate anticholinergic properties. Avoid co-use when possible since the effects of bethanechol, a cholinergic agonist, may be diminished. If co-use is necessary, monitor for the intended clinical response.
Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Butalbital; Aspirin; Caffeine; Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Carbinoxamine: (Moderate) Drugs that possess antimuscarinic properties, such as carbinoxamine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Celecoxib; Tramadol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Cetirizine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Cevimeline: (Moderate) Cevimeline and bethanechol are both cholinergic agonists. Coadministration is expected to result in additive parasympathomimetic effects.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlordiazepoxide; Amitriptyline: (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.
Chlordiazepoxide; Clidinium: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Chlorpheniramine; Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlorpheniramine; Hydrocodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlorpheniramine; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlorpheniramine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Chlorpromazine: (Moderate) Drugs that possess antimuscarinic properties, such as chlorpromazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Cholinesterase inhibitors: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Clemastine: (Moderate) Drugs that possess antimuscarinic properties, such as clemastine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Clomipramine: (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.
Clozapine: (Moderate) Drugs that possess antimuscarinic properties, such as clozapine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Codeine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Codeine; Guaifenesin: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility. (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Codeine; Phenylephrine; Promethazine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility. (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects. (Moderate) Drugs that possess antimuscarinic properties, such as promethazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Codeine; Promethazine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility. (Moderate) Drugs that possess antimuscarinic properties, such as promethazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Desipramine: (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.
Desloratadine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dexmethylphenidate: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dextroamphetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dextromethorphan; Bupropion: (Moderate) Bupropion exhibits moderate anticholinergic properties. Avoid co-use when possible since the effects of bethanechol, a cholinergic agonist, may be diminished. If co-use is necessary, monitor for the intended clinical response.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects. (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Dextromethorphan; Quinidine: (Moderate) Drugs that possess antimuscarinic properties, such as quinidine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Dicyclomine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Diethylpropion: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Diphenhydramine: (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Diphenhydramine; Ibuprofen: (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Diphenhydramine; Naproxen: (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Diphenhydramine; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects. (Moderate) Drugs that possess antimuscarinic properties, such as diphenhydramine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Diphenoxylate; Atropine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa. (Moderate) Pharmacodynamic interactions between antidiarrheals and drugs that enhance peristalsis are theoretically possible. It is wise to avoid use of antidiarrheals in patients who require bethanechol.
Disopyramide: (Moderate) Disopyramide possesses clinically significant antimuscarinic properties and these appear to be dose-related. It is possible that disopyramide could antagonize the muscarinic actions of cholinergic agonists. Clinicians should be alert to this possibility.
Dobutamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Donepezil: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Donepezil; Memantine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Dopamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Doxapram: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Doxepin: (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.
Ephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Ephedrine; Guaifenesin: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Epinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Fentanyl: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Fexofenadine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Flavoxate: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Fosfomycin: (Moderate) Bethanechol increases gastrointestinal motility and may decrease the systemic absorption of fosfomycin when the drugs are coadministered. This may result in lower fosfomycin serum concentrations and urinary excretion. Since fosfomycin is given as a single dose, separating times of administration may limit the interaction.
Galantamine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Glycopyrrolate: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Glycopyrrolate; Formoterol: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Guaifenesin; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Guaifenesin; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Guanidine: (Moderate) Guanidine and bethanechol are both cholinergic agonists. Coadministration is expected to result in additive parasympathomimetic effects.
Homatropine; Hydrocodone: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa. (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Hydrocodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Hydrocodone; Ibuprofen: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Hydromorphone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Hyoscyamine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Ibuprofen; Oxycodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Ibuprofen; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Imipramine: (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.
Indacaterol; Glycopyrrolate: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Isoproterenol: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Levorphanol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Lidocaine; Epinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Lisdexamfetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Loratadine; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Maprotiline: (Major) Maprotiline may antagonize some of the effects of parasympathomimetics. However, bethanechol has occasionally been used therapeutically to offset some of the adverse antimuscarinic effects of cyclic antidepressants. Due to their anticholinergic actions, some cyclic antidepressants like maprotiline may potentially antagonize the therapeutic actions of the cholinesterase-inhibitors used for the treatment of dementia.
Mecamylamine: (Major) Ganglionic blocking agents, such as mecamylamine and trimethaphan, may cause significant hypotension when co-administered with bethanechol. Severe abdominal symptoms may precede the drop in blood pressure.
Meperidine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Methadone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Methamphetamine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Methscopolamine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Methylphenidate: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Midodrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Morphine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Morphine; Naltrexone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Naproxen; Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Neostigmine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Neostigmine; Glycopyrrolate: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided. (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Norepinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Nortriptyline: (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.
Olanzapine: (Moderate) Drugs that possess antimuscarinic properties, such as olanzapine, are pharmacologic opposites of bethanechol (a direct agonist at muscarinic cholinergic receptors). These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Olanzapine; Fluoxetine: (Moderate) Drugs that possess antimuscarinic properties, such as olanzapine, are pharmacologic opposites of bethanechol (a direct agonist at muscarinic cholinergic receptors). These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Olanzapine; Samidorphan: (Moderate) Drugs that possess antimuscarinic properties, such as olanzapine, are pharmacologic opposites of bethanechol (a direct agonist at muscarinic cholinergic receptors). These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Oliceridine: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Opiate Agonists: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Oxybutynin: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Oxycodone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Oxymorphone: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Perphenazine; Amitriptyline: (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.
Phendimetrazine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Phentermine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Phentermine; Topiramate: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Physostigmine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Pilocarpine: (Moderate) Pilocarpine and bethanechol are both cholinergic agonists. Coadministration is expected to result in additive parasympathomimetic effects.
Pralidoxime: (Moderate) Pralidoxime and bethanechol are both cholinergic agonists. Coadministration is expected to result in additive parasympathomimetic effects.
Prilocaine; Epinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Procainamide: (Moderate) Drugs that possess antimuscarinic properties, such as procainamide, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Promethazine: (Moderate) Drugs that possess antimuscarinic properties, such as promethazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Promethazine; Dextromethorphan: (Moderate) Drugs that possess antimuscarinic properties, such as promethazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Promethazine; Phenylephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects. (Moderate) Drugs that possess antimuscarinic properties, such as promethazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Propantheline: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Protriptyline: (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.
Pseudoephedrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Pseudoephedrine; Triprolidine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Pyridostigmine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Quinidine: (Moderate) Drugs that possess antimuscarinic properties, such as quinidine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Racepinephrine: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Remifentanil: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Rivastigmine: (Major) Cholinergic agonists can cause additive pharmacodynamic effects if used concomitantly with cholinesterase inhibitors. Concurrent use is unlikely to be tolerated by the patient and should be avoided.
Scopolamine: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Serdexmethylphenidate; Dexmethylphenidate: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Sincalide: (Moderate) Sincalide-induced gallbladder ejection fraction may be affected by bethanechol. False study results are possible in patients with drug-induced hyper- or hypo-responsiveness; thorough patient history is important in the interpretation of results.
Sufentanil: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Sympathomimetics: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Tapentadol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Thioridazine: (Moderate) Drugs that possess antimuscarinic properties, such as thioridazine, are pharmacologic opposites of bethanechol. These agents should not be used with bethanechol except when the specific intent is to counteract excessive actions of one or the other.
Tramadol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Tramadol; Acetaminophen: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Tricyclic antidepressants: (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.
Trihexyphenidyl: (Major) The muscarinic actions of drugs known as parasympathomimetics, including both direct cholinergic receptor agonists and cholinesterase inhibitors, can antagonize the antimuscarinic actions of anticholinergic drugs, and vice versa.
Trimipramine: (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.
Trospium: (Moderate) Pharmacologically, parasympathomimetic drugs enhance muscarinic/cholinergic function. Because trospium is an antimuscarinic, the muscarinic actions of drugs known as parasympathomimetics, including direct cholinergic agonists, could be antagonized when used concomitantly with trospium.
Bethanechol is a synthetic muscarinic stimulant. It does not inactivate acetylcholinesterase. Bethanechol exerts its parasympathomimetic effects by a direct action on muscarinic (cholinergic) receptors, all of which can be antagonized by atropine. Bethanechol primarily affects the urinary and GI tracts. Its effect on the bladder results from stimulation of muscarinic receptors in the detrusor muscle. The detrusor contracts, decreasing bladder capacity and producing urination. Bethanechol also stimulates ureteral peristalsis and relaxes the trigone and external sphincter. Because bethanechol is a direct-acting agonist, spinal cord injury will not compromise these actions.
Stimulation of muscarinic receptors in the GI tract restores peristalsis, increases motility, and increases the resting lower esophageal sphincter pressure. Bethanechol also stimulates the lower GI tract, producing defecation. Bethanechol produces a much more vigorous response in denervated than in normal smooth muscle. It does not stimulate nicotinic receptors and is not degraded by acetylcholinesterase. Bethanechol is a preferred drug in the treatment of postpartum and postoperative nonobstructive urinary retention, and it also can counteract bladder dysfunction often seen with phenothiazines and tricyclic antidepressants.
Bethanechol is administered orally and subcutaneously. After administration, the distribution of bethanechol is not well known. Due to its quaternary (i.e., charged) state, bethanechol does not penetrate the blood-brain barrier at therapeutic doses. Because it is not susceptible to degradation by acetylcholinesterase, bethanechol has a longer duration of action than endogenous acetylcholine. The mechanism of elimination is unknown.
-Route-Specific Pharmacokinetics
Oral Route
Bethanechol poorly absorbed from the gastrointestinal tract. Its oral bioavailability is unknown. Onset of action occurs within 30-90 minutes when taken orally. It is a short-acting drug; effects typically last 1 hour when taken orally.
Subcutaneous Route
Parenteral doses of bethanechol are much more potent than equivalent oral doses and should be administered cautiously. Onset of action occurs within 5-15 minutes when given subcutaneously. It is a short-acting drug; effects typically last 2 hours when taken subcutaneously.