[The oral direct thrombin inhibitor Ximelagatran Prophylaxis of venous thromboembolism in hip and knee replacement].

Aim: The efficacy and safety of the new oral, direct and selective thrombin inhibitor Ximelagatran and its active form Melagatran was analysed in patients undergoing total hip or knee replacement.

Methods And Patients: Methro II, a randomised, double-blind controlled dose-finding study, involved 1876 patients. Melagatran (1, 1.5, 2.25 or 3 mg; twice daily; start: immediately before surgery) was given subcutaneously, followed by orally administered Ximelagatran (8, 12, 18 or 24 mg, twice daily, day after surgery) and compared to subcutaneously administered dalteparin (5000 IE, once daily). Methro III was a randomised, double blind controlled study involving 2788 patients. The fixed dose of 3 mg Melagatran was given (start: 4-12 hours postoperatively) followed by oral Ximelagatran (24 mg, twice daily, day after surgery) compared to subcutaneous enoxaparin (40 mg, once daily). In both studies, dalteparin or enoxaparin was applied at the evening before operation; the treatment lasted 8 to 11 days. A bilateral venography was performed at the last day of treatment.

Results: In the Methro II study, 1270 patients underwent total hip, 606 total knee replacement. In both groups the thromboembolism rate was reduced depending on the dose of Ximelagatran/Melagatran. Compared to dalteparin, it was significantly lower for the Ximelagatran/Melagatran group with the highest dose. In the Methro III study 1923 patients underwent a total hip, 865 a total knee replacement. The thromboembolism rate was 31% for the Ximelagatran/Melagatran group compared to 27% for the enoxaparin group. In both studies blood loss and transfusion requirement were in the same range as with low weight molecular heparins.

Conclusions: A fixed subcutaneously given dose of Melagatran, followed by orally administered Ximelagatran is effective and well tolerated as prophylaxis against venous thromboembolism.