Pharmacology · single question
What is the mechanism of action of Lisinopril?
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Correct answer: D. ACE inhibitor (blocks angiotensin-converting enzyme)
Lisinopril is an ACE inhibitor (Angiotensin-Converting Enzyme inhibitor). It blocks the conversion of angiotensin I to angiotensin II (the potent vasoconstrictor) and also prevents degradation of bradykinin (a vasodilator). This results in vasodilation and decreased blood pressure. Key dental relevance: ACE inhibitors can cause persistent dry cough (bradykinin accumulation), angioedema, and orthostatic hypotension.
- A. CORRECT. Lisinopril is an ACE inhibitor — it prevents conversion of angiotensin I to angiotensin II, reducing vasoconstriction and aldosterone release.
- B. Incorrect. Beta-1 blockers (metoprolol, atenolol) reduce heart rate and cardiac output but do not block ACE.
- C. Incorrect. Calcium channel blockers (amlodipine, nifedipine) block L-type calcium channels in vascular smooth muscle — not ACE. Note: nifedipine causes gingival enlargement.
- D. Incorrect. ARBs (losartan, valsartan) block the angiotensin II receptor directly — lisinopril blocks the enzyme that makes angiotensin II, not the receptor.