There is a real and viable need in the anticoagulant arena for a safe, robust, effective oral anticoagulant drug that measures up to warfarin in providing protection against thrombosis and compares favorably (if not better) with regard to safety profile, without the need for routine and often cumbersome monitoring. Many potential antithrombotic agents are in development, and the oral factor Xa inhibitors are one such class of drug. By inhibiting both free and clot-bound factor Xa complexes, the oral factor Xa inhibitors prolong activated partial thromboplastin time and prothrombin times in a dose-dependent manner without the need for antithrombin, thus differing from drugs such as fondaparinux, heparin, etc. Early human experiments demonstrated a favorable pharmacokinetic and pharmacodynamic profile with good absorbtion, effective inhibition of factor Xa activity and no significant accumulation of the drug in the body. Other studies on healthy human volunteers showed an efficacious antithrombotic profile, minimal interactions with food, fasting and concomitant antiplatelet-drug (aspirin and naproxen) administration, and effectiveness in extremes of body weight (>120 kg). Rivaroxaban has been tested in trials to prevent and treat venous thromboembolism, and the results were indicative of a safe, effective and therapeutic pharmacological profile. Results so far from phase III studies currently underway that assess the role of rivaroxaban in preventing arterial thromboembolism in both high-risk atrial fibrillation and acute coronary syndrome patients will be the focus of interest and indeed intense speculation as to whether we should modify our current practice in favor of using a more convenient and effective pharmacological agent.
(c) 2007 Prous Science.