Thrombin inhibitors as anticoagulant agents

Hirudin and its analogues and the synthetic antithrombin agents are interesting new antithrombotic agents that have been studied in a number of well-designed randomized clinical trials and further studies are underway. These agents offer certain advantages over heparin and low-molecular-weight heparin, and at least one agent is orally bioavailable. Studies have shown that the specific thrombin inhibitors can significantly decrease the incidence of composite cardiac endpoints in acute ischemic syndromes (following thrombolysis for myocardial infarction, unstable angina, and non-Q wave myocardial infarction and coronary angioplasty), but it is disappointing that the benefits obtained during short-term treatment are not sustained in the long term. Recent data are reviewed here from clinical trials supporting the use of the specific antithrombin agents in the treatment of acute cardiac ischemic syndromes, the prevention and treatment of venous thromboembolism, and the management of heparin-induced thrombocytopenia.