Bethanechol is preferred over pilocarpine for treating postoperative urinary retention because:

• A Bethanechol crosses the blood-brain barrier and increases central cholinergic tone
• B Bethanechol stimulates nicotinic receptors at the bladder ganglia
• C Bethanechol has a shorter duration of action, reducing cardiovascular side effects
• D Bethanechol is resistant to cholinesterase hydrolysis and has predominantly muscarinic urinary tract selectivity ✓

Explanation

Bethanechol is a choline ester that resists hydrolysis by acetylcholinesterase due to its carbamyl ester structure, providing a sustained oral effect. It is selective for muscarinic receptors (no nicotinic activity) and predominantly stimulates the urinary bladder (detrusor) and GI smooth muscle with relatively less cardiovascular effect than pilocarpine. It does not cross the blood-brain barrier and is not used for ophthalmic purposes.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.