Postural hypotension and failure of ejaculation is most commonly seen in treatment with:(1991)
**Core Concept**
Postural hypotension and failure of ejaculation are common side effects associated with anticholinergic drugs, which block the action of acetylcholine at muscarinic receptors. This leads to a decrease in parasympathetic tone, resulting in decreased blood vessel diameter and a subsequent drop in blood pressure, as well as impaired smooth muscle contraction in the bladder neck and seminal vesicles.
**Why the Correct Answer is Right**
The correct answer is an anticholinergic drug. By blocking muscarinic receptors in the autonomic nervous system, these drugs reduce parasympathetic tone, leading to decreased vasodilation and a subsequent drop in blood pressure, resulting in postural hypotension. Additionally, impaired smooth muscle contraction in the bladder neck and seminal vesicles leads to failure of ejaculation. This is because acetylcholine stimulates smooth muscle contraction, which is essential for ejaculation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because while it may have some anticholinergic effects, it is not the most commonly associated drug with postural hypotension and failure of ejaculation.
**Option B:** This option is incorrect because it is a beta-blocker, which primarily affects the sympathetic nervous system and is not associated with these side effects.
**Option C:** This option is incorrect because it is an antihistamine, which primarily affects the histamine receptor and is not associated with these side effects.
**Clinical Pearl / High-Yield Fact**
Anticholinergic drugs can cause a range of side effects due to their blockade of muscarinic receptors, including dry mouth, constipation, and urinary retention, in addition to postural hypotension and failure of ejaculation.
**Correct Answer:** B.