Urecholine - Drug Monograph

Introduction

Urecholine (bethanechol chloride) is a parasympathomimetic cholinergic agent that acts as a direct muscarinic receptor agonist. It is a synthetic choline ester that is resistant to hydrolysis by acetylcholinesterase, making it longer-acting than acetylcholine. Urecholine is primarily used for its effects on the urinary and gastrointestinal systems.

Mechanism of Action

Urecholine directly stimulates muscarinic receptors in smooth muscle and exocrine glands, mimicking the effects of acetylcholine. Unlike acetylcholine, it is not hydrolyzed by cholinesterase enzymes, resulting in prolonged duration of action. The drug increases tone and motility of the detrusor urinae muscle and gastrointestinal smooth muscle while causing relaxation of sphincters.

Indications

• Treatment of acute postoperative and postpartum nonobstructive urinary retention
• Management of neurogenic atony of the urinary bladder with retention
• Treatment of congenital megacolon (Hirschsprung's disease)
• Management of gastroesophageal reflux (off-label use)

Dosage and Administration

• Oral: 10-50 mg 3-4 times daily
• Subcutaneous: 2.5-5 mg up to 3-4 times daily

• Renal impairment: Use with caution; consider dose reduction
• Hepatic impairment: No specific recommendations; use cautiously
• Elderly: Start with lower doses due to increased sensitivity
• Pediatric: 0.2 mg/kg/dose orally 3-4 times daily (not to exceed 50 mg/day)

Pharmacokinetics

Contraindications

• Hypersensitivity to bethanechol or any component
• Mechanical obstruction of the gastrointestinal or urinary tract
• Hyperthyroidism
• Peptic ulcer disease
• Asthma
• Coronary artery disease
• Bradycardia
• Hypotension
• Epilepsy
• Parkinson's disease

Warnings and Precautions

• Risk of bladder rupture if administered with urinary tract obstruction
• May cause severe hypotension
• Use with caution in patients with autonomic neuropathy
• May precipitate asthma attacks in susceptible individuals
• Can cause syncope in some patients
• Avoid intravenous administration (may cause circulatory collapse)

Drug Interactions

• Anticholinergics: May antagonize effects of Urecholine
• Cholinesterase inhibitors: Additive cholinergic effects
• Beta-blockers: Increased risk of bradycardia
• Ganglion-blocking agents: Enhanced hypotensive effects
• Quinidine: May antagonize cholinergic effects

Adverse Effects

• Abdominal cramps
• Nausea and vomiting
• Diarrhea
• Flushing
• Sweating
• Salivation
• Headache

• Severe hypotension
• Bradycardia
• Bronchospasm
• Syncope
• Seizures (rare)
• Atrioventricular block

Monitoring Parameters

• Blood pressure and heart rate
• Urinary output and bladder function
• Respiratory status
• Electrolytes (with prolonged use)
• Signs of cholinergic excess
• Therapeutic response

Patient Education

• Take on an empty stomach to reduce nausea
• Report any difficulty breathing, chest pain, or severe abdominal pain
• Avoid driving or operating machinery until effects are known
• Inform all healthcare providers about Urecholine use
• Report persistent diarrhea or excessive sweating
• Do not crush or chew tablets
• Store at room temperature away from moisture

References

1. American Society of Health-System Pharmacists. AHFS Drug Information. Bethesda, MD: 2023. 2. Brunton LL, Hilal-Dandan R, Knollmann BC. Goodman & Gilman's: The Pharmacological Basis of Therapeutics. 13th ed. New York: McGraw-Hill; 2018. 3. Micromedex Solutions. Bethanechol. Truven Health Analytics. 2023. 4. Lexicomp Online. Bethanechol: Drug Information. Wolters Kluwer Health; 2023. 5. FDA prescribing information for Urecholine (bethanechol chloride). 6. Chapple CR, et al. Muscarinic receptor antagonists in the treatment of overactive bladder. Urology. 2000;55(5A):33-46. 7. Andersson KE. Muscarinic receptor agonists and antagonists: effects on the urinary bladder. Handb Exp Pharmacol. 2012;(208):375-400.