Preclinical and clinical characteristics of rivaroxaban: a novel, oral, direct factor Xa inhibitor.

There are several novel anticoagulants in development that target factor Xa(FXa)-the pivotal point of the coagulation cascade. One promising agent is rivaroxaban (a highly selective, oral, direct FXa inhibitor), which is in advanced clinical development for the prevention and treatment of thromboembolic disorders. Oral rivaroxaban may be given in fixed once-daily doses, with the potential for no coagulation monitoring. These properties, along with results from preclinical and clinical studies, suggest that rivaroxaban may have advantages over current treatments. Studies in arterial and venous animal models demonstrated that rivaroxaban has potent antithrombotic effects, without prolonging bleeding times. In healthy subjects, rivaroxaban was well tolerated, with a predictable pharmacological profile and a low propensity for clinically relevant drug-drug interactions. Phase II studies of rivaroxaban for the prevention of venous thromboembolism (VTE) after major orthopedic surgery support these findings. The results also suggested that a total daily dose range of 5 to 20 mg rivaroxaban had similar efficacy and safety to enoxaparin, and that 10 mg rivaroxaban once daily was the optimal dose. This review assesses the preclinical and clinical characteristics of rivaroxaban, and discusses phase II findings with rivaroxaban for the prevention of VTE after major orthopedic surgery.