Clinical results with direct thrombin inhibitors.

Direct thrombin inhibitors inactivate thrombin without the need for antithrombin and some inactivate not only thrombin but also fibrin-bound thrombin. Hirudin has been shown to be more effective than low-dose unfractionated heparin and low molecular weight heparin for the prevention of deep vein thrombosis in high-risk orthopaedic patients. Major studies are assessing the value of direct thrombin inhibitors in patients with acute coronary syndromes. Currently, argatroban is the drug of choice in patients with heparin-induced thrombocytopenia.