Low-molecular-weight heparins: Weeks or months instead of days of treatment

Low-molecular-weight heparins (LMWHs) have been used for more than a decade in the prophylaxis and treatment of venous thromboembolism and recently in coronary artery disease. During the past few years, the duration of treatm ent has been increased in several pathologic conditions. A number of clinic al studies provided evidence that the duration of prophylaxis after hip rep lacement should be prolonged up to 35 days after surgery. Several clinical trials concluded that LMWHs provide an effective and safe alternative to or al anti-coagulants in the secondary prevention of deep vein thrombosis. A r ecent trial showed that extended dalteparin treatment is useful for protect ion against further complications while patients are waiting for invasive p rocedures. Finally, LMWHs seem to be safe during pregnancy.