New oral anticoagulants for the treatment of venous thromboembolism: Understanding differences and similarities

Venous thromboembolism (VTE) is a major cause of morbidity, mortality, and healthcare expenditure. In the United States, approximately 0.1 % of the population experiences an initial VTE event each year. Anticoagulation therapy is the cornerstone of acute VTE treatment and for prevention of recurrent VTE events. Conventional anticoagulants, including heparin, low-molecular-weight heparins, fondaparinux, and vitamin K antagonists are widely used but have limitations. Newer oral anticoagulant agents, including direct thrombin inhibitors (e.g., dabigatran etexilate) and direct factor Xa inhibitors (e.g., rivaroxaban, apixaban, and edoxaban) have been developed to attempt to overcome some of the limitations of conventional anticoagulant therapy. These new oral agents have been evaluated for safety and efficacy in large, randomized clinical trials in the treatment and secondary prevention of VTE with results that are comparable to conventional therapy. Dabigatran, rivaroxaban, apixaban, and edoxaban are important new treatment options for patients with VTE. In this review, we compare these new agents and their associated clinical trials in VTE treatment.