skip to main content

ACE Inhibitor Cough — EECC MCQ

Instant feedback + full explanation. One question, done properly.

EasyHypertension & Preventive CardiologyACE Inhibitor CoughEECC

A 45-year-old woman with hypertension is started on an ACE inhibitor. She develops a persistent dry cough after 4 weeks. What is the mechanism and recommended alternative?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — ACEi-induced cough is caused by accumulation of bradykinin and substance P due to inhibition of ACE-mediated degradation; switch to an ARB which does not affect bradykinin metabolism

ACE inhibitors inhibit the enzyme that degrades both angiotensin I (to angiotensin II) and bradykinin. Bradykinin accumulation in the bronchial mucosa stimulates C-fibre sensory nerves, causing the characteristic dry, non-productive cough (affecting 5-20% of patients, more common in women and East Asian populations). The cough typically develops within weeks to months and resolves within 1-4 weeks of stopping the ACEi. ARBs block the angiotensin II AT1 receptor directly without affecting bradykinin metabolism, so cough is not a class effect of ARBs. Importantly, ACEi-induced angioedema (a separate, more serious adverse effect involving bradykinin) also contraindicates ARNIs (which contain the neprilysin inhibitor that also degrades bradykinin).

Reference: ESC (2024): Hypertension Guidelines; BNF