New antithrombotic agents for the prevention and treatment of deep vein thrombosis.

Besides low molecular weight heparins (LMWHs) a number of new antithrombotic agents have been evaluated mainly in the prevention of deep vein thrombosis (DVT) and, to a lesser extent, in the treatment of established DVT. They include the Pentasaccharide, a synthetic ultra LMWH, Dermatan Sulphate, a glycosaminoglycan which activates heparin cofactor II, Orgaran, a mixture of Heparan and of Dermatan Sulphate, Hirulog and Hirudin, two direct thrombin inhibitors. The efficacy and safety of these compounds have been studied in comparison with a placebo or with unfractionated heparin but not with LMWH which is considered as a gold standard for these clinical indications. It is thus difficult at present to appreciate the advantages of these new antithrombotic agents over conventional LMWH therapy.