What did we learn from new oral anticoagulant treatment?

Orally active direct inhibitors of thrombin and factor Xa have now been approved for treatment or prevention of deep vein thrombosis,and stroke associated with atrial fibrillation. The factor Xa inhibitor, rivaroxaban, has shown promising results in the treatment of acute coronary syndrome but is not yet approved for that indication. These agents share a rapid onset and are cleared with half lives of approximately 10 hours. At present there is no approved antidote for either class of anticoagulant, making the treatment of life-threatening bleeding episodes problematic. These agents have fewer drug interactions than warfarin, have a predictable clearance, and hence do not require monitoring. Patients with renal insufficiency have delayed clearance and hence may have elevated levels of the drug leading to increased risk of bleeding.