Bethanechol

Oral
Acute postoperative nonobstructive urinary retention, Acute postpartum nonobstructive urinary retention, Neurogenic atony of the bladder with retention

Should be taken on an empty stomach.

Hyperthyroidism, peptic ulcer, latent or active bronchial asthma; coronary artery disease, recent MI, pronounced bradycardia or hypotension, vasomotor instability; epilepsy, parkinsonism; conditions when increased muscular activity of the gastrointestinal tract or urinary bladder may prove harmful (e.g. following recent urinary bladder surgery, gastrointestinal resection and anastomosis, possible gastrointestinal obstruction); conditions wherein the strength or integrity of the gastrointestinal or bladder wall is questionable; mechanical obstruction of the gastrointestinal and genitourinary tract; bladder neck obstruction, acute inflammatory lesions of the gastrointestinal tract, spastic gastrointestinal disturbances, peritonitis, marked vagotonia.

Patient with bacteriuria. Pregnancy and lactation.

Significant: Increased risk of reflux infection, particularly if the patient has bacteriuria.
Cardiac disorders: Tachycardia.
Eye disorders: Lacrimation, miosis.
Gastrointestinal disorders: Salivation, nausea, vomiting, abdominal cramps or discomfort, colic, borborygmi, belching, diarrhoea.
General disorders and administration site conditions: Malaise.
Nervous system disorders: Headache, seizure.
Renal and urinary disorders: Urinary urgency.
Respiratory, thoracic and mediastinal disorders: Asthma attack, bronchial constriction.
Skin and subcutaneous tissue disorders: Diaphoresis.
Vascular disorders: Hypotension, flushing.

Parenteral/PO/SC: C

Evaluate bladder and sphincter adequacy prior to treatment initiation.

Symptoms: Nausea, abdominal discomfort, vomiting, salivation, involuntary defecation and urination, lacrimation, sweating, flushing of the skin, transient dyspnoea, palpitation, bradycardia, peripheral vasodilation resulting in hypertension, transient heart block, and substernal pressure or pain. Management: Supportive treatment. Perform aspiration and gastric lavage. Administer IV, SC, or IM atropine sulfate 2-4 hourly as needed based on response to manage muscarinic effects. Supportive treatment may include diazepam 5-10 mg given via IV, small doses of tubocurarine (with assisted respiration) to control muscle twitching, and oxygen administration.

Additive effects and increased toxicity with other cholinergic drugs or anticholinesterase agents (e.g. neostigmine). May cause a critical fall in blood pressure (usually preceded by severe abdominal symptoms) when given with ganglionic blocking agents. Atropine, procainamide, quinidine, epinephrine, and other sympathomimetic amines may antagonise the effects of bethanechol.

Description:
Mechanism of Action: Bethanechol, a choline ester, is a quaternary ammonium parasympathomimetic agent that exhibits the muscarinic activity of acetylcholine. It acts by directly stimulating the parasympathetic nervous system, thereby releasing acetylcholine at the nerve endings. It increases bladder muscle tone resulting in contractions which initiate urination. Additionally, it stimulates gastric motility, enhances gastric tone, and restores impaired rhythmic peristalsis.
Onset: Within 30 minutes. Peak effect: Approx 60-90 minutes.
Duration: Approx 1 hour (therapeutic doses); 6 hours (large doses [300-400 mg]).
Pharmacokinetics:
Absorption: Poorly absorbed from the gastrointestinal tract.
Distribution: Does not cross the blood-brain barrier (at usual therapeutic doses).

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 2370, Bethanechol. https://pubchem.ncbi.nlm.nih.gov/compound/Bethanechol. Accessed Mar. 29, 2023.

Store between 15-30°C. Protect from light.

Other Drugs Acting on the Genito-Urinary System

N07AB02 - bethanechol ; Belongs to the class of choline esters. Used as parasympathomimetics.

Anon. Bethanechol. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 15/03/2023.

Anon. Bethanechol. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 15/03/2023.

Bethanechol Chloride Tablet (Amneal Pharmaceuticals of New York, LLC). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 15/03/2023.

Buckingham R (ed). Bethanechol Chloride. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 15/03/2023.

Joint Formulary Committee. Bethanechol Chloride. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 15/03/2023.

Myotonine Tablets 25 mg (Glenwood GmbH). MHRA. https://products.mhra.gov.uk. Accessed 15/03/2023.

Uriflow (PHARMASIA). MIMS Philippines. http://www.mims.com/philippines. Accessed 20/03/2023.