low-molecular-weight heparin (LMWH), a class of drugs used to prevent potentially fatal blood clots in patients undergoing surgery or patients at risk for blood clots. It has been used to prevent deep vein thrombosis in patients undergoing hip and knee replacements. LMWH has an advantage over regular heparin in that predictable plasma levels are achieved, obviating the need for regular monitoring of prothrombin time and partial thromboplastin time.
