Which is an ACE inhibitor?

• A. Lisinopril
• B. Valsartan
• C. Amlodipine
• D. Furosemide

Answer: (A)

ACE inhibitors block the enzyme that converts angiotensin I to angiotensin II, which lowers angiotensin II–mediated vasoconstriction and decreases aldosterone-driven water and salt retention. Lisinopril is an ACE inhibitor, so it fits this mechanism. Valsartan works differently by blocking the angiotensin II receptor (an ARB), not the enzyme. Amlodipine is a calcium channel blocker that promotes vasodilation through a separate pathway. Furosemide is a loop diuretic that increases excretion of Na and water.