Anatomical Therapeutic Chemical Classification System
Argatroban, a synthetic L-arginine derivative, is a direct thrombin inhibitor (molecular weight 526.65) that binds reversibly to thrombin. Argatroban exerts its anticoagulant effect independently of antithrombin III and inhibits fibrin formation; activation of coagulation factors V, VIII and XIII; activation of protein C; and platelet aggregation.
Dabigatran etexilate is a small molecule prodrug which does not exhibit any pharmacological activity. After oral administration, dabigatran etexilate is rapidly absorbed and converted to dabigatran by esterase-catalysed hydrolysis in plasma and in the liver. Dabigatran is a potent, competitive, reversible direct thrombin inhibitor and is the main active principle in plasma.
Desirudin is a highly potent and selective inhibitor of free circulating and clot-bound thrombin. The anticoagulant properties of desirudin are demonstrated by its ability to prolong the clotting time of human or rat plasma whether induced directly (thrombin time) or via the intrinsic (aPTT) or extrinsic (PT) pathways.
Lepirudin is a recombinant hirudin derived from yeast cells. Lepirudin is a highly specific direct inhibitor of thrombin. Its mode of action is independent of antithrombin III.