Question

Which of the following is a P2Y₁₂ enzyme inhibitor?

• A. Clopidogrel
• B. Aspirin
• C. Dipyridamole
• D. Tirofiban

Hint:

P2Y$_12$ inhibitors like clopidogrel are crucial in dual antiplatelet therapy, often combined with aspirin, for preventing cardiovascular events.

Answer 1

The Correct Option is A

P2Y$_12$ is a subtype of ADP receptor found on platelet surfaces that plays a crucial role in platelet aggregation and thrombus formation. Inhibiting this receptor prevents ADP-mediated platelet activation and aggregation, thus acting as an antiplatelet agent. - Clopidogrel is a thienopyridine class antiplatelet drug that irreversibly inhibits the P2Y$_12$ ADP receptor on platelets, preventing platelet aggregation. It is commonly used in the prevention of stroke, myocardial infarction, and other thrombotic events.
- Aspirin acts by irreversibly inhibiting cyclooxygenase-1 (COX-1) enzyme, thereby blocking thromboxane A$_2$ synthesis and platelet aggregation, but does not inhibit P2Y$_12$.
- Dipyridamole inhibits phosphodiesterase and increases cAMP levels in platelets, leading to inhibition of aggregation, but is not a P2Y$_12$ inhibitor.
- Tirofiban is a glycoprotein IIb/IIIa receptor antagonist that prevents fibrinogen binding to platelets, also not a P2Y$_12$ inhibitor. Hence, clopidogrel is the correct choice as a P2Y$_12$ enzyme inhibitor.