Current concepts for the prevention of venous thromboembolism.

Venous thromboembolism (VTE) is a major cause of morbidity and mortality worldwide and the annual incidence of VTE is 1 per 1000. The individual risk for venous thromboembolism may be substantially higher and is determined by expositional and dispositional factors. Unfractionated heparin and warfarin have been the mainstays for the prevention of VTE until the early 1980s. Bleeding complications and side effects limited the use of these agents and subsequently low molecular weight heparins (LMWH) were introduced into clinical practice. These are most commonly used for the prophylaxis and treatment of VTE today. In the last decade, the pace of development of further anticoagulants has accelerated with the introduction of new treatment regimens and new substances. In this context, novel drugs directed against clotting factor Xa (such as fondaparinux) and direct thrombin inhibitors (such as melagatran/ximelagatran) have been developed. Fondaparinux shows a favourable efficacy/safety profile and has been documented to be cost-effective compared to enoxaparin in the US and the UK.