Which anticoagulant is a direct thrombin inhibitor?

Which anticoagulant is a direct thrombin inhibitor?

• A. Dabigatran
• B. Warfarin
• C. Rivaroxaban
• D. Apixaban

Answer: (A)

Directly blocking thrombin’s activity is the defining feature here. Dabigatran binds to thrombin itself (factor IIa) and prevents it from converting fibrinogen to fibrin and from activating platelets. That direct inhibition of thrombin is what makes it a direct thrombin inhibitor. The other drugs work differently: warfarin is a vitamin K antagonist that reduces the production of several clotting factors, indirectly lowering coagulation. Rivaroxaban and apixaban inhibit factor Xa, which reduces thrombin generation but does not inhibit thrombin directly.

Directly blocking thrombin’s activity is the defining feature here. Dabigatran binds to thrombin itself (factor IIa) and prevents it from converting fibrinogen to fibrin and from activating platelets. That direct inhibition of thrombin is what makes it a direct thrombin inhibitor.

The other drugs work differently: warfarin is a vitamin K antagonist that reduces the production of several clotting factors, indirectly lowering coagulation. Rivaroxaban and apixaban inhibit factor Xa, which reduces thrombin generation but does not inhibit thrombin directly.