Antiplatelet Drug 1

Question

Vignette: A 34-year-old woman is brought to the emergency department with severe chest pain radiating to her left arm and jaw. On examination, her blood pressure is 150/90 mmHg, heart rate is 110 bpm, and respirations are 20/min. An ECG shows ST-segment elevation in leads II, III, and aVF. She is diagnosed with an acute inferior wall myocardial infarction and is given aspirin, nitroglycerin, and morphine for pain relief. Oxygen is also administered. The physician plans to give a drug that inhibits platelet aggregation by irreversibly inhibiting a certain enzyme. Which of the following drugs is most likely to be administered?

Choices

A. Clopidogrel

B. Heparin

C. Rivaroxaban

D. Enoxaparin

E. Warfarin

Answer

A. Clopidogrel

Explanation

The patient's symptoms and ECG findings are indicative of an acute inferior wall myocardial infarction. Aspirin, which inhibits cyclooxygenase, and nitroglycerin, which reduces preload, have been administered. The physician now plans to administer a drug that inhibits platelet aggregation by irreversibly inhibiting the P2Y12 component of adenosine diphosphate receptors on the platelet surface, a key step in platelet activation and aggregation. This describes the mechanism of action of clopidogrel (choice A). Clopidogrel is often used in conjunction with aspirin in the acute setting of myocardial infarction to provide a dual antiplatelet therapy.

Heparin (choice B), Rivaroxaban (choice C), and Enoxaparin (choice D) are anticoagulant drugs that inhibit clotting factors but do not act directly on platelet aggregation. Warfarin (choice E) is a Vitamin K antagonist that interferes with the synthesis of vitamin K-dependent clotting factors in the liver, but it takes several days to achieve a therapeutic effect and is not used in the acute setting of myocardial infarction.