bethanechol

Bethanechol is a medication approved by the FDA for treating urinary retention that occurs after surgery, childbirth, or due to a nerve disorder. Bethanechol is used off-label to treat gastroesophageal reflux disease (GERD).

Bethanechol belongs to a class of medications known as genitourinary cholinergics. Bethanechol works by stimulating the parasympathetic nervous system, which makes the bladder detrusor muscle contract and expelsl urine.

Bethanechol has effects similar to acetylcholine, a natural chemical (neurotransmitter) in the body that nerve endings secrete to make muscles contract. Bethanechol stimulates muscarinic receptors, protein molecules on smooth muscle cell membranes that activate muscle contraction.

Bethanechol works on all 5 types of muscarinic receptors M1-M5, of which M3 receptors are the type predominantly found in the bladder detrusor muscle. Bethanechol also stimulates gastric motility by stimulating M1 receptors in the gastrointestinal tract.

The FDA-approved uses of bethanechol include:

Adults:

• Postsurgical urinary retention
• Postpartum nonobstructive urinary retention
• Neurogenic bladder

Off-label uses include:

• Urinary retention in children
• GERD in adults and children

• Do not prescribe bethanechol to patients with the following conditions:
  • Hypersensitivity
  • Hyperthyroidism
  • Peptic ulcer
  • Latent bronchial asthma
  • Active bronchial asthma
  • Bradycardia
  • Orthostatic hypotension
  • Vasomotor instability
  • Coronary artery disease
  • Epilepsy/seizures
  • Parkinsonism
  • Arrhythmias 
  • Angle-closure glaucoma
  • Intestinal resection or anastomosis
  • Urinary obstruction
  • Severe miosis
• Bethanechol should be avoided in patients with compromised durability of the bladder wall or gastrointestinal tract.
• Bethanechol should not be used if there is a mechanical obstruction in the urinary tract because the muscle tone from the drug can make the urine reflux back into the kidneys.
• If the patient has bacteria in the urine, there is a potential for reflux infection if the sphincter muscle fails to relax as the bethanechol makes the bladder contract.

Common side effects of bethanechol include:

• Urinary urgency
• Headache
• Feeling unwell (malaise)
• Seizure
• Rapid heart rate (tachycardia)
• Low blood pressure (hypotension)
• Flushing
• Excessive sweating (diaphoresis)
• Colic
• Abdominal cramps
• Rumbling noises in the stomach (borborygmi)
• Diarrhea
• Increased gastric motility
• Belching (eructation)
• Salivation
• Nausea
• Vomiting
• Bronchial constriction
• Asthma
• Watery eyes (lacrimation)
• Constriction of eye pupils (miosis)

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

• Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
• Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
• Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
• Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Tablet

• 5 mg
• 10 mg
• 25 mg
• 50 mg

Adult:

Urinary Retention

• 10-50 mg orally three/four times daily
• Some patients may require doses of 50-100 mg orally twice daily
• Take 1 hour before meals or 2 hours after meals

GERD (Off-label)

• 25 mg orally four times daily
• Take 1 hour before meals or 2 hours after meals

Pediatric:

Urinary Retention (off-label)

• 0.3-0.6 mg/kg/day orally divided three/four times daily
• Take 1 hour before meals or 2 hours after meals

GERD (off-label)

• 0.3-0.6 mg/kg/day orally divided four times daily
• Take 1 hour before meals or 2 hours after meals

• Bethanechol overdose can cause symptoms that include abdominal discomfort, nausea, vomiting, salivation, sweating, and flushing.
• Atropine sulfate is the antidote for bethanechol and may be administered subcutaneously or, in an emergency, intravenously.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Bethanechol has no known severe interactions with other drugs.
• Bethanechol has no known serious interactions with other drugs.
• Bethanechol has moderate interactions with at least 74 different drugs.
• Mild interactions of bethanechol include:
  • desipramine
  • donepezil
  • galantamine
  • mecamylamine
  • pantothenic acid
  • procainamide
  • trazodone

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

• There are no studies on bethanechol use in pregnant women. Use with caution during pregnancy if maternal benefits outweigh potential fetal risks.
• It is not known if bethanechol is present in breast milk. Maternal use of the drug has the potential for causing serious adverse reactions in the breastfeeding infant. Based on the importance of the drug to the mother, decision should be taken to discontinue the drug or nursing.

• Take bethanechol exactly as directed.
• Store bethanechol safely out of reach of children.
• In case of overdose, seek medical help immediately or contact Poison Control.