Recombinant hirudin in the prevention of venous thromboembolism in patients undergoing elective hip surgery

Venous thromboembolism is a major cause of mortality and morbidity in patients undergoing orthopedic surgery. In these patients systemic prophylaxis with anticoagulants appears to be the most effective approach to reduce venous thromboembolic events. Low-molecular-weight heparins (LMWHs) are the prophylactic agents of choice in patients undergoing elective hip replacement. However, their use is still associated with a 15% incidence of deep vein thrombosis (DVT); hence, there is a need for potentially more effective agents. Among these, hirudin and other selective thrombin inhibitors have recently been evaluated. The main pharmacologic properties of recombinant hirudin and the clinical trials carried out with this agent in the prevention of DVT in patients undergoing elective hip replacement are reviewed in this article. Overall, the results of these clinical trials are quite promising; they actually indicate that a b.i.d. subcutaneous injection of 15 or 20 mg of recombinant hirudin is an effective and safe prophylactic approach. Hirudin was more effective than unfractionated heparin, given at a low fixed dose, in two clinical trials and of a LMWH in one clinical trial. However, further studies are required to define the role of recombinant hirudin in the prevention of venous thromboembolism in orthopedic surgery patients.