Ximelagatran is the first oral anticoagulant in a new class of drugs called direct thrombin inhibitors. Two studies suggest that ximelagatran is at least as effective as warfarin in preventing stroke in high risk patients with atrial fibrillation. Ximelagatran may also reduce the rate of major cardiovascualr events after a myocardial infarction, compared to placebo. Ximelagatran does not require dose adjustments or routine blood monitoring. As with warfarin, bleeding risks increase with higher doses of ximelagatran. There is, however, no specific antidote to help manage bleeding. The safety of ximelagatran will not be fully known without further evaluation and surveillance for potential liver toxicity and drug interactions.