Which property distinguishes bethanechol from acetylcholine?

• A It stimulates both nicotinic and muscarinic receptors
• B It has predominant nicotinic ganglionic activity
• C It crosses the blood-brain barrier readily
• D It is resistant to hydrolysis by acetylcholinesterase ✓

Explanation

Bethanechol carries a carbamyl ester linkage that acetylcholinesterase hydrolyses extremely slowly, giving it a longer duration of action than acetylcholine. Its beta-methyl substitution makes it act almost purely on muscarinic receptors. The best distractor, option A, describes carbachol, which retains substantial nicotinic activity because it lacks the beta-methyl group.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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