Direct thrombin inhibitors such as argatroban and bivalirudin are administered by which route and what do they inhibit?

Direct thrombin inhibitors such as argatroban and bivalirudin are administered by which route and what do they inhibit?

• A. They are given orally and inhibit factor Xa
• B. They are given subcutaneously and inhibit factor Xa
• C. They are given orally; activate plasmin
• D. They are given intravenously and inhibit thrombin (IIa)

Answer: (D)

Direct thrombin inhibitors act by blocking thrombin itself, not factor Xa, and they are given by intravenous infusion. Argatroban and bivalirudin bind directly to thrombin’s active site, preventing thrombin from converting fibrinogen to fibrin and from promoting further platelet activation. They inhibit both free thrombin and thrombin that is already bound in clots, which helps stop ongoing coagulation and clot growth. This is different from oral Xa inhibitors or indirect inhibitors like heparin, and they do not activate plasmin or fibrinolysis.

Direct thrombin inhibitors act by blocking thrombin itself, not factor Xa, and they are given by intravenous infusion. Argatroban and bivalirudin bind directly to thrombin’s active site, preventing thrombin from converting fibrinogen to fibrin and from promoting further platelet activation. They inhibit both free thrombin and thrombin that is already bound in clots, which helps stop ongoing coagulation and clot growth. This is different from oral Xa inhibitors or indirect inhibitors like heparin, and they do not activate plasmin or fibrinolysis.