Low molecular weight heparins: the optimal treatment for venous thromboembolism.

Venous thromboembolism (VTE) is a common vascular complication that requires immediate as well as long-term treatment. Unfractionated heparin (UFH), followed by oral anticoagulants (OAs), is of proved efficacy in the treatment of deep venous thrombosis (DVT) and pulmonary embolism (PE). However, low molecular weight heparins (LMWHs) have successfully replaced UFH both in the prevention and in the initial treatment of DVT and PE. Recent trials evaluated the efficacy and safety of LMWH therapy as an alternative to vitamin K antagonists in long-term VTE secondary prophylaxis for all patients and in specific subgroups. LMWHs differ considerably from each other. These agents were studied separately, administered according to various protocols, in various doses and for different duration of treatment. Results from prospective randomized trials, conducted during the last decade, indicate that LMWHs are at least as effective and yet safer than OAs in the long-term treatment of VTE. In this brief overview, we consider the potential advantages of treatment with LMWH in patients with VTE.