Which medication is NOT an ACE inhibitor?

• A. Lisinopril
• B. Benazepril
• C. Losartan
• D. Enalapril

Answer: (C)

ACE inhibitors work by blocking the enzyme that converts angiotensin I to angiotensin II, reducing angiotensin II–mediated vasoconstriction and aldosterone release. Drugs that end with -pril are typically ACE inhibitors, including lisinopril, benazepril, and enalapril. Losartan, however, is an angiotensin II receptor blocker; it prevents angiotensin II from acting at its receptor rather than inhibiting the enzyme itself. That difference in action means it is not an ACE inhibitor.