Oral factor Xa inhibitors for thromboprophylaxis in major orthopedic surgery: a review

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a major cause of morbidity and mortality in patients undergoing major orthopedic surgery. Routine thromboprophylaxis has been the standard of care over the last 20 years. Currently available options for the prevention of VTE in major orthopedic surgery include low molecular weight heparins, vitamin K antagonists, and, more recently, the synthetic pentasaccharide fondaparinux. Although effective, all these drugs have several limitations and new oral antithrombotics offering predictable, effective and safe anticoagulation are strongly needed. This overview focuses on the most advanced oral direct inhibitors to factor Xa rivaroxaban, apixaban, LY517717 and YM150; specifically, the results of phase II and III studies and the designs of ongoing clinical trials in patients undergoing elective hip and knee replacement are reviewed.