Low molecular weight heparins for venous thromboembolism.

Five years ago, we concluded that in patients undergoing major orthopaedic surgery, prophylactic use of a low molecular weight heparin (LMWH) gave greater protection against deep vein thrombosis (DVT) than did conventional unfractionated heparin (UFH). The risk of bleeding appeared to be the same. It was unclear whether the clinical advantages of the LMWHs offset their greater cost. In the UK, four LMWHs ([symbol: see text]certoparin, dalteparin, enoxaparin and tinzaparin) are now licensed for prophylaxis against venous thromboembolism during or after surgery; a fifth (nadroparin) is licensed but not yet marketed in the UK. Dalteparin, enoxaparin and tinzaparin are licensed for the treatment of DVT. Additionally, tinzaparin is licensed for the treatment of pulmonary embolism (PE). Here, we review the use of LMWHs for these indications.