Pharmacology · single question
A patient is taking apixaban for stroke prevention. What is the mechanism of action of this drug?
Show answer and explanation
Correct answer: C. Inhibits Factor Xa
Apixaban (Eliquis) is a direct, selective Factor Xa inhibitor. Factor Xa catalyzes the conversion of prothrombin to thrombin, a central step in the coagulation cascade. By blocking Factor Xa, apixaban prevents thrombin generation and subsequent clot formation without requiring monitoring. Other Factor Xa inhibitors include rivaroxaban and edoxaban. Dabigatran is a direct thrombin inhibitor.
- A. ❌ Warfarin blocks vitamin K epoxide reductase, reducing production of clotting factors II, VII, IX, and X.
- B. ❌ Clopidogrel and ticagrelor inhibit platelet ADP (P2Y12) receptors — antiplatelet agents, not anticoagulants.
- C. ✅ CORRECT – Apixaban directly and selectively inhibits Factor Xa, preventing thrombin generation and clot formation.
- D. ❌ Direct thrombin inhibitors include dabigatran (Pradaxa) and argatroban — not apixaban.