The treatment of severe or recurrent deep venous thrombosis. Beneficial effect of the co-administration of antiplatelet agents with or without rheological effects, and anticoagulants.

Deep venous thromboses can be divided into two groups according to their pathogenesis, anatomical features and differing responses to therapy. The first and most frequent consists of so-called simple venous thrombosis while the second group, which is less common, comprises severe or recurrent venous thrombosis characterised by a multifactorial pathogenesis, a mixed thrombus rich in platelets and by an incomplete response to both prophylactic and therapeutic treatment with anticoagulants (heparin or vitamin K antagonist). In a randomized, prospective blind study in patients with severe or recurrent venous thrombosis, which included 6 groups each of 100 patients, co-administration of anticoagulants with various types of antiplatelet agent, either with rheological effects (piracetam, buflomedil, pentoxifylline) or without them (dipyridamole), has shown a beneficial potentiating antithrombotic effect with those drugs possessing rheological effects and the absence of this effect with dipyridamole.