The Development of Low Molecular Weight Heparins

The develqnnent of low molecular weight heparin (LMWH) has added a new dimension to the clini management of thrombotic disorders. These agents have revolutionized the prophylaxis of post-surgical tiirombosis (4-5). More recently these dmgs have been used for the treatment of trauma related thrombosis, hi particular, their relative effects on platelets are minimal in comparison to heparin. Thus, these agents are of value in platelet compromised patients. 

For the past few decades, heparin has been widely used for the prevention of postoperative thiomboemboUsm (6,7). However, there are several adverse side-effects associated with the use of heparin such as bleeding, heparin induced thrombocytopenia, heparin induced thrombosis (8,9) and osteoporosis (10). In addition, the regimen of pioph actic heparin used in the prevention of deep venous thrombosis (DVT) is tedious, requiring 2 to 3 daily injections because of the limited bioavailability and short half-life of heparin when administered subcutaneously. 

Preparation of Low Molecular Weight Heparin and Lower Low Molecular Weight Heparin 

The most extensively studied method of prophylaxis of DVT in orthopedic patients in recent years has been with LMWH. Evidence fliat this treatment is both effective and safe is quickly accumulating. 

Several randomized trials using venography or fibrinogen uptake as the endpoint have 

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Hirsch J, Ofosu F, Levine M. The development of low molecular weight heparins for clinical use. In Yerstrate M, Vermylen H, Arnout J, eds. Thrombosis and Hemostasis. Leuven University Press, Leuven, Netherlands, 1987. 

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