Argatroban - A novel thrombin-specific inhibitor for the treatment of heparin-induced thrombocytopenia

Studies in recent years have led to an enhanced understanding of the critical role that thrombin plays in the formation of arterial and venous thrombi. In the past several years, attention has focused on soluble thrombin and clot-bound thrombin. The differentiation is important because clot-bound thrombin retains its ability to activate coagulation factors, yet appears to be resistant to the standard anticoagulant heparin. Consequently, a number of new drugs chemically distinct from heparin have been developed, which are capable of inhibiting clot-bound thrombin. These drugs offer the promise of greater effectiveness as antithrombotic agents. Argatroban is a small, synthetic molecule that tightly binds to and inactivates both soluble and clot-bound thrombin. Because it is chemically and immunogenically distinct from heparin, argatroban has been evaluated in a large prospective study for its ability to treat heparin-induced thrombocytopenia. This immunological reaction to heparin causes potentially catastrophic complications, including widespread thrombi in the venous and arterial circulation, and if untreated can cause myocardial infarction, stroke, loss of limbs or death. Argatroban has been demonstrated to be an effective treatment for heparin-induced thrombocytopenia.