Which condition is a contraindication for ACE inhibitors?

Which condition is a contraindication for ACE inhibitors?

• A. Bilateral renal artery stenosis.
• B. Mild hepatic impairment.
• C. Well-controlled diabetes.
• D. Hypothyroidism.

Answer: (A)

When the kidneys rely on angiotensin II to maintain filtration pressure, blocking this system with an ACE inhibitor can backfire. In bilateral renal artery stenosis, both kidneys depend on angiotensin II to constrict the efferent arteriole and keep the glomerular filtration rate (GFR) adequate despite reduced blood flow. Turning off angiotensin II with an ACE inhibitor removes that compensatory constriction, lowering glomerular pressure and risking a sharp drop in GFR and potential kidney injury. That makes this condition a contraindication for ACE inhibitors, and monitoring or alternative therapies are advised in such cases. The other scenarios do not pose the same risk and are not contraindications.

When the kidneys rely on angiotensin II to maintain filtration pressure, blocking this system with an ACE inhibitor can backfire. In bilateral renal artery stenosis, both kidneys depend on angiotensin II to constrict the efferent arteriole and keep the glomerular filtration rate (GFR) adequate despite reduced blood flow. Turning off angiotensin II with an ACE inhibitor removes that compensatory constriction, lowering glomerular pressure and risking a sharp drop in GFR and potential kidney injury. That makes this condition a contraindication for ACE inhibitors, and monitoring or alternative therapies are advised in such cases. The other scenarios do not pose the same risk and are not contraindications.