Abstract

The treatment of acute venous thromboembolism and prophylaxis of recurrent events with heparin/low molecular weight heparin followed by vitamin K antagonists is limited by several factors. Oral direct thrombin inhibitors (ODTIs) showed a better pharmacological activity and might be an alternative in the treatment of venous thromboembolism. The Thrombin Inhibition in Venous Thromboembolism (THRIVE) program performed some studies developing the ODTI ximelagatran for this indication, and it is presented in the overview. The aim of the THRIVE I study was the dose finding, and that of the THRIVE IV study the applicability in hemodynamic stabile pulmonary embolism. A prospective, randomized, double blind trial was performed to compare oral ximelagatran with enoxaparin/warfarin for a 6-month treatment of acute venous thrombosis (THRIVE II and V). A second double blind study compared ximelagatran with placebo over 18 months after a 6-month anticoagulant therapy of acute deep vein thrombosis. The efficacy and safety of treatment of patients with acute deep venous thrombosis who received 2 infinity 36 mg ximelagatran was not inferior to that of patients who received a conventional anticoagulant for prophylaxis of recurrent events over 6 months. Ximelagatran 2 infinity 24 mg significantly reduced recurrent thromboembolic events compared to placebo without increasing the risk for hemorrhage. A reversible symptomless increase of alanine aminotransferase occurs in 6% to 9.6% of patients between months 2 and 4. The results of the follow-up studies suggest that thromboembolic events may recur in patients with acute venous thromboembolism after termination of treatment with both vitamin K antagonists and ximelagatran.