Apixaban, an oral direct Factor Xa inhibitor: awaiting the verdict.

For the last half-century, despite its many limitations warfarin has been the mainstay of treatment for patients with venous and arterial thromboembolic disease. During the past decade, a number of new oral anticoagulant agents have been developed that may offer an alternative to warfarin. Emerging data suggest that Factor Xa may be a target for inhibition. Apixaban is one such agent. It is a potent, selective, reversible, and orally bioavailable FXa inhibitor that demonstrates antithrombotic efficacy, with a favorable pharmacokinetic profile. At present, the safety and efficacy of apixaban for the prophylaxis and treatment of venous thromboembolism is being evaluated in Phase II and Phase III trials involving nearly 25,000 patients. Trials are also underway involving over 20,000 patients for secondary prevention after acute coronary syndromes and the prevention of stroke in patients with non-valvular atrial fibrillation. This review article discusses the discovery, pharmacokinetics, attributes, and current clinical trials of this emerging drug.