Drug that selectively acts on AlphalA receptors (blocking action), used in treatment of Benign Prostatic Hypertrophy and has least or no cardiac side effects is:
**Core Concept**
The question requires an understanding of alpha-adrenergic blockers, specifically those that selectively act on alpha-1A receptors, and their use in treating Benign Prostatic Hypertrophy (BPH) with minimal cardiac side effects.
**Why the Correct Answer is Right**
The drug in question is an alpha-1 adrenergic blocker that selectively acts on alpha-1A receptors to relax smooth muscle in the prostate and bladder neck, thereby alleviating symptoms of BPH. This selective action results in fewer cardiac side effects compared to non-selective alpha blockers. The drug's mechanism of action involves competing with endogenous norepinephrine for binding to alpha-1A receptors, leading to vasodilation and smooth muscle relaxation.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not specify a drug that selectively acts on alpha-1A receptors.
**Option B:** This option is incorrect because it is a non-selective alpha blocker that can cause significant cardiac side effects.
**Option C:** This option is incorrect because it is a different class of medication that is not primarily used to treat BPH.
**Clinical Pearl / High-Yield Fact**
Alpha-1A selective blockers like the correct answer are preferred over non-selective blockers to minimize cardiac side effects, such as hypotension and tachycardia, making them a safer choice for patients with BPH.
**Correct Answer:** Tamsulosin. Tamsulosin, an alpha-1A selective adrenergic blocker, is used in the treatment of Benign Prostatic Hypertrophy with minimal cardiac side effects.