Which adverse effect requires monitoring in a patient taking doxazosin for BPH?</n>

• A. Orthostatic hypotension
• B. Tinnitus
• C. Hyperglycemia
• D. Nephrotoxicity

Answer: (A)

Orthostatic hypotension is the adverse effect to monitor with doxazosin for BPH. Doxazosin is an alpha-1 blocker that relaxes smooth muscle in the prostate and bladder but also causes vasodilation in the peripheral vessels. This can lead to a drop in blood pressure when moving from lying or sitting to standing, producing dizziness, lightheadedness, or even fainting. The first-dose effect is well known, so clinicians often start with a small dose and may have patients take the first dose at night to lessen falls risk. In practice, check blood pressure in different positions after starting or changing the dose, and educate patients to rise slowly, sit if they feel dizzy, and avoid driving until they know how they respond, especially if taking other blood-pressure–lowering medicines. Other options like tinnitus, hyperglycemia, or nephrotoxicity are not typical concerns with this medication.