Name two common alpha-1 antagonists used for BPH and one major adverse effect to monitor.

• A. Tamsulosin, Doxazosin; orthostatic hypotension
• B. Finasteride, Dutasteride; xerostomia
• C. Sildenafil, Tadalafil; priapism
• D. Bethanechol, Pilocarpine; sweating

Answer: (A)

Two commonly used alpha-1 blockers for BPH are tamsulosin and doxazosin. They work by relaxing smooth muscle in the prostate and bladder neck, which reduces obstruction and improves urine flow. The major adverse effect to monitor is orthostatic hypotension—dizziness or lightheadedness when standing—because alpha-1 blockade can cause blood vessels to dilate. Tamsulosin is more uroselective, so it may cause less blood pressure impact than doxazosin, but both require counseling about getting up slowly and monitoring blood pressure, especially after starting or increasing the dose. The other drug pairs shown belong to different classes (5-alpha-reductase inhibitors, PDE5 inhibitors, or cholinergic agonists) and are not the alpha-1 blockers typically used for BPH or their primary adverse effect to monitor.