Low molecular weight heparins: current use and indications

Heparin is a naturally occurring anticoagulant synthesized and secreted primarily by the mast cells in the body. Unfractionated heparin has been commonly used for prevention and treatment of arterial and venous thrombosis. However, because of complications, such as bleeding, thrombocytopenia, and osteoporosis, clinicians continue to search for additional antithrombotic options. Over the past 2 decades, low molecular weight heparins (LMWH) have been intensely investigated, and researchers have reported several advantages of these compounds over unfractionated heparin. LMWH was previously approved for use in the prophylaxis of deep venous thrombosis (DVT) and in the inpatient treatment of DVT and pulmonary embolism (PE). In May 1998, LMWH (Enoxaparin, Rhone-Poulenc Rorer, Collegeville, PA) was deemed approvable by the Food and Drug Administration for inand outpatient treatment of DVT and PE and extended use of LMWH for outpatient treatment of DVT and PE.