Which alpha-1 blocker is most selective for alpha-1A receptors in the prostate and bladder neck, making it preferred in BPH with minimal effect on blood pressure?
- A Prazosin
- B Doxazosin
- C Tamsulosin ✓
- D Phentolamine
Correct answer: C. Tamsulosin
Explanation
Tamsulosin has high selectivity for the alpha-1A receptor subtype, which predominates in the prostate and bladder neck, causing relaxation of smooth muscle and improving urinary flow. Because it has less affinity for alpha-1B receptors in blood vessels, it causes less postural hypotension compared to non-selective alpha-1 blockers. Prazosin and doxazosin are non-selective alpha-1 blockers used primarily for hypertension. Phentolamine blocks both alpha-1 and alpha-2 receptors.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.