Apixaban is the third new oral anticoagulant to go on sale, following dabigatran and rivaroxaban, and it has already been approved in Europe for preventing venous thromboembolism in patients undergoing elective hip or knee replacement surgery. Out of these three oral anticoagulants approved in Europe, compared to the current standard preventative treatment against venous thromboembolism, enoxaparin, rivaroxaban excelled in the record experiment, and apixaban excelled in the advance experiment. Rivaroxaban's curative effects were slightly superior, but it caused more severe bleeding than apixaban. Researchers attributed these differences to medication time, as rivaroxaban was taken 6-8 hours after surgery in the record experiment, while apixaban was used 18 hours after surgery in the advance experiment. These drugs have better curative effect when used closer to time of surgery, but also have an increased bleeding risk. Clinical research showed that compared to a daily subdermal injection of 40mg enoxaparin, 2 oral 2.5mg dosages of apixaban had better preventative effects against venous thromboembolism following hip or knee replacement surgery and did not increase bleeding risk.