Clopidogrel (Plavix) inhibits which platelet receptor?

Clopidogrel (Plavix) inhibits which platelet receptor?

• A. P2Y12 receptor
• B. GP IIb/IIIa receptor
• C. PAR-1 receptor
• D. TXA2 receptor

Answer: (A)

Clopidogrel blocks the P2Y12 receptor on platelets. When ADP binds this receptor, it promotes platelet activation and aggregation; clopidogrel’s active metabolites irreversibly inhibit P2Y12, preventing ADP signaling and reducing platelet activation. Because the drug is a prodrug activated in the liver (via CYP enzymes) and its effect is irreversible, the antiplatelet effect lasts for the lifespan of the platelets (about 7–10 days) until new platelets are made. This differs from drugs that target other receptors: GP IIb/IIIa antagonists act on the final aggregation step, PAR-1 antagonists block thrombin signaling, and TXA2 receptor blockade (or aspirin) reduces thromboxane A2 effects rather than the ADP receptor.

Clopidogrel blocks the P2Y12 receptor on platelets. When ADP binds this receptor, it promotes platelet activation and aggregation; clopidogrel’s active metabolites irreversibly inhibit P2Y12, preventing ADP signaling and reducing platelet activation. Because the drug is a prodrug activated in the liver (via CYP enzymes) and its effect is irreversible, the antiplatelet effect lasts for the lifespan of the platelets (about 7–10 days) until new platelets are made. This differs from drugs that target other receptors: GP IIb/IIIa antagonists act on the final aggregation step, PAR-1 antagonists block thrombin signaling, and TXA2 receptor blockade (or aspirin) reduces thromboxane A2 effects rather than the ADP receptor.