New oral anticoagulants: prevention of VTE in phase III studies in total joint replacement surgery and the hospitalized medically-ill patients.

Effective venous thromboembolism prophylaxis in hospitalized medically-ill patients and those undergoing orthopaedic surgery remains a challenge for clinicians in the United States. Several new oral anticoagulants, which either directly inhibit the activity of thrombin or factor Xa have been developed and studied for venous thromboembolism (VTE) prevention in phase III trials in these patient populations. These new medications demonstrate several advantages over traditional anticoagulants, including their administration at fixed doses with no requirement for routine coagulation monitoring. Such advantages may potentially be offset by the lack of well-studied methods to reverse their anticoagulant effects and the potential need for standardized testing to monitor their activity in certain situations. This review will provide an overview of the clinical trial results of dabigatran, apixaban and rivaroxaban for VTE prevention in the orthopaedic and medically-ill hospitalized patients.