Low molecular weight heparin, heparin, and warfarin

Low molecular weight heparin is effective for the prevention and treatment of venous thromboembolism. Low molecular weight heparin has the practical advantage that it does not require anticoagulant monitoring and dose adjustment. The simplified therapy provided by low molecular weight heparin may allow many patients with venous thromboembolism to be cared for in an outpatient setting, with the potential for major savings in health care costs. In the setting of preventing venous thromboembolism after hip or knee replacement surgery, further cost-effectiveness studies are required to determine the ultimate clinical role of low molecular weight heparin. Extensive data document a consistent high rate of inadequate therapy when empirical or intuitive approaches are used to administer intravenous unfractionated heparin in patients with venous thromboembolism or cardiovascular disease. A validated protocol should be used for intravenous heparin treatment. The evidence is accumulating that warfarin is more effective than aspirin for preventing thromboembolism in patients with atrial fibrillation.