Pentasaccharides. The new anticoagulants.

Venous thromboembolism VTE remains a common but preventable disease. The last decade has witnessed major advances in VTE treatment and prophylaxis. Low molecular weight heparins LMWH became the agents of choice in the treatment of deep venous thrombosis DVT and are increasingly used in the treatment of stable pulmonary embolism PE. Increasing focus on simplicity and efficacy has led to the discovery of the synthetic pentasaccharides, substances that specifically inhibit factor Xa activity, producing an antithrombotic effect without affecting other coagulation factors or platelets. Fondaparinux, the first pentasaccharide introduced into the market, was first tried as a prophylactic agent against VTE in patients undergoing major orthopedic procedures, such as hip fracture, total hip and knee replacements, such approach appeared to be more effective than LMWH. Fondaparinux was also used, with promising results, in prophylaxis in patients undergoing major abdominal surgery and high risk medical patients. Pentasaccharides were recently tried in the treatment of both DVT and PE. The largest clinical investigation program ever undertaken in this therapeutic area, has shown that pentasaccharides are as safe and as effective as either unfractionated heparin UFH or LMWH, with the added convenience of once daily injection, no need for monitoring the anticoagulant effect and no major side effects such as thrombocytopenia. Therefore, the efficacy, the safety profile and the added convenience for both patients and physicians alike, will probably keep pentasaccharides as the front runner among new anticoagulants of the future. This article focuses on the use of fondaparinux as a prophylactic agent against VTE in patients undergoing major orthopedic and abdominal surgery along with high risk medical patients; it will also discuss the recent promising data on its use to treat active DVT and PE.