Which drug reduces/diminishes the antihypertensive effect of lisinopril?

Correct answer: C. NSAIDs (ibuprofen)

• A. Corticosteroids can raise blood pressure due to mineralocorticoid effects, but the primary drug interaction that specifically diminishes lisinopril's effect is NSAIDs.
• B. Antibiotics do not significantly interfere with lisinopril's antihypertensive action.
• C. Correct. NSAIDs (like ibuprofen) can blunt the antihypertensive effect of ACE inhibitors like lisinopril by inhibiting prostaglandin synthesis, which causes vasoconstriction and sodium retention — counteracting the ACE inhibitor's effect.
• D. Diuretics are often used WITH ACE inhibitors as complementary antihypertensives, not to diminish their effect.