Each of the following parasympathomimetic drugs is correctly matched with an appropriate pharmacological action EXCEPT:
Correct Answer: D
Rationale: The correct answer is D. Bethanechol is a parasympathomimetic drug that primarily acts on muscarinic receptors in the bladder and gastrointestinal tract, causing increased smooth muscle contraction and promoting urination and improved GI motility. It does not affect intraocular pressure.
A, B, and C are incorrect:
A: Methacholine - acts as a muscarinic agonist causing bronchoconstriction, not vasodilation.
B: Neostigmine - inhibits acetylcholinesterase leading to increased acetylcholine levels, enhancing neuromuscular transmission, not directly stimulating skeletal muscles.
C: Pilocarpine - acts on muscarinic receptors in the eye, causing miosis and increased aqueous humor outflow, not increased sweat secretion.