Bethanechol

Bethanechol is a parasympathomimetic choline ester that selectively stimulates muscarinic receptors without any effect on nicotinic receptors. Unlike acetylcholine, bethanechol is not hydrolyzed by cholinesterase and will therefore have a long duration of action. Bethanechol does not involve the action of the muscarinic M3 receptor subtype in-vitro (Benavides-Haro et al. (2003)

Bethanechol is sold under the brand names Duvoid (Roberts), Myotonachol (Glenwood), Urecholine (Merck Frosst) and Urocarb (Hamilton).

Uses
Bethanechol is sometimes given orally or subcutaneously to treat urinary retention resulting from general anesthetic or diabetic neuropathy of the bladder, or to treat gastrointestinal atony (lack of muscular tone). The muscarinic receptors in the bladder and gastrointestinal tract stimulate contraction of the bladder and expulsion of urine, and increased gastrointestinal motility, respectively. Bethanechol should be used to treat these disorders only after mechanical obstruction is ruled out as a possible cause.

Its potential benefit in the treatment of cerebral palsy has been investigated. Bethanechol is a powerful cholinergic agent which efficiently crosses the blood - brain barrier and may have powerful nootropic properties in enhancement of neural signaling and processing speed as well.

Atropine is given preoperatively to prevent voiding of the bowel/bladder during surgery, Bethanechol is then given postoperatively to revert this action.

Contraindications
Use of bethanechol, as well as all other muscarinic receptor agonists, is contraindicated in patients with asthma, coronary insufficiency, peptic ulcers, intestinal obstruction and hyperthyroidism. The parasympathomimetic action of this drug will exacerbate the symptoms of these disorders.