Recent clinical trials in the treatment of venous thromboembolism and unstable angina with low molecular weight heparins.

Low molecular weight heparins (LMWHs) have a more predictable anticoagulant response, better bioavailability when administered by subcutaneous injection, and a longer plasma half-life than unfractionated heparin. Consequently, LMWHs can be administered by subcutaneous injection, once daily, without laboratory monitoring. When used in this way, LMWHS are as safe and effective as unfractionated heparin administered by continuous intravenous infusion with laboratory monitoring for the treatment of venous thrombosis and pulmonary embolism, and at least as safe and effective as unfractionated heparin for the treatment of unstable angina. Three recent studies demonstrated that because of their improved pharmacokinetic properties, LMWHs can be used to treat selected patients with venous thrombosis in the out-of-hospital setting.