Ticagrelor is preferred over clopidogrel in ACS because it:
- A Does not require CYP2C19 activation and binds the P2Y12 receptor reversibly, providing more predictable and faster platelet inhibition regardless of CYP2C19 polymorphism ✓
- B Is irreversibly binds the P2Y12 receptor with greater potency than clopidogrel
- C Inhibits COX-1 in addition to ADP receptor blockade, providing dual antiplatelet action
- D Blocks both P2Y1 and P2Y12 receptors, providing more complete ADP pathway inhibition than clopidogrel
Correct answer: A. Does not require CYP2C19 activation and binds the P2Y12 receptor reversibly, providing more predictable and faster platelet inhibition regardless of CYP2C19 polymorphism
Explanation
Ticagrelor is a direct-acting, reversible P2Y12 receptor antagonist that does not require CYP2C19 bioactivation. This eliminates the variability seen with clopidogrel in poor CYP2C19 metabolisers (reduced active metabolite generation, 'clopidogrel resistance'). Its reversible binding also allows faster recovery of platelet function before surgery. Clopidogrel is a prodrug that binds P2Y12 irreversibly after CYP2C19 activation.
Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.