Which medication is an antiplatelet used to prevent myocardial infarction or thrombus?

• A. Beta-blocker
• B. Nitroglycerin
• C. Aspirin
• D. Statin

Answer: (C)

Antiplatelet therapy aims to stop platelets from clumping together to prevent arterial clots that can cause a heart attack. Aspirin works by irreversibly inhibiting the enzyme COX-1 in platelets, which lowers the production of thromboxane A2, a key signal for platelet aggregation. Because platelets cannot make new proteins, this effect lasts for the platelets’ lifetime (about 7–10 days). This makes aspirin especially effective for preventing myocardial infarction and thrombotic events.

Beta-blockers reduce heart rate and myocardial oxygen demand but don’t prevent platelet aggregation. Nitroglycerin relieves chest pain through vasodilation without reducing clot formation. Statins lower cholesterol and help stabilize plaques, lowering cardiovascular risk, but their primary action isn’t antiplatelet.

So the antiplatelet used to prevent myocardial infarction or thrombus is aspirin.