ACE inhibitors can cause a cough due to bradykinin accumulation; this is a reason to consider what alternative class?

• A. ARB
• B. Thiazide diuretic
• C. Beta-blocker
• D. Calcium channel blocker

Answer: (A)

The cough from ACE inhibitors comes from bradykinin buildup in the lungs when ACE is blocked. Bradykinin is degraded by ACE, so inhibiting ACE raises its levels and can trigger a dry, persistent cough. The best alternative class is angiotensin II receptor blockers (ARBs). They block the angiotensin II receptor but do not inhibit ACE, so bradykinin levels aren’t increased and the cough is usually avoided. ARBs can be used when cough limits ACE inhibitor therapy, though they still carry risks like hyperkalemia and hypotension. Other drug classes don’t specifically address the bradykinin-caused cough, so they’re not the first-line substitute for this reason.