PATIENTS AT RISK OF VENOUS THROMBOEMBOLISM - CLINICAL-RESULTS WITH REVIPARIN

Perioperative thromboembolism can be effectively prevented by low-dose heparin. However, its clinical benefit is limited, due to the risk of bleeding, the need for multiple daily doses, infrequent disorders of platelet function and other potential side effects. Low molecular weig ht heparin (LMWH) was developed with the aim that the antithrombotic e fficacy of heparin could be maintained, while the risk of bleeding and other side effects would be reduced. Prior to recent studies, the ant icipated clinical benefit of LMWH remained a controversial issue. We h ave reviewed the clinical pharmacology and the results of several pros pective trials using reviparin a LMWH which has been compared with unf ractionated heparin (UFH) and another LMWH. The efficacy and safety of reviparin was examined in the prevention of venous thromboembolism in high risk patients undergoing elective major abdominal and hip surger y. The results of these clinical trials show that reviparin is as effe ctive as UFH in preventing venous thromboembolism whilst having a lowe r incidence of bleeding complications. Of major significance was the f inding that a very low dose of reviparin, namely 1750 anti-Xa IU once daily, was found to be as effective as UFH in preventing deep vein thr ombosis whilst having a significantly lower incidence of bleeding comp lications in patients undergoing major abdominal surgery. Reviparin ha s also been shown to be effective and safe as enoxaprin in patients un dergoing elective hip surgery. Further clinical trials are required to test different dosage regimens as a thromboprophylactic agent in high risk patients. It is possible that reviparin and other LMWHs with sim ilar pharmacological properties may have an important clinical benefit over earlier compounds. However, this needs to be assessed in large s cale, double-blind, randomised clinical trials.