2 The technology
2.1 Rivaroxaban (Xarelto, Bayer HealthCare) is an anticoagulant that directly inhibits activated factor X (factor Xa). Inhibiting factor Xa interrupts the pathway of the blood coagulation cascade, inhibiting both thrombin formation and development of thrombi. Rivaroxaban has a marketing authorisation for the prevention of venous thromboembolism (VTE) in adult patients undergoing elective hip or knee replacement surgery.
2.2 The summary of product characteristics (SPC) states that rivaroxaban should be taken orally once daily in 10-mg doses. The initial dose should be taken 6–10 hours after surgery, provided that haemostasis has been established. The SPC further states that the duration of treatment depends on the individual risk of the patient for VTE, which is determined by the type of orthopaedic surgery. Recommended treatment durations are 5 weeks for patients having major hip surgery, and 2 weeks for patients having major knee surgery. According to the SPC, approximately 14% of the treated patients across the phase III studies experienced adverse reactions. Bleeding and anaemia occurred in approximately 3.3% and 1% of patients, respectively. Other common adverse reactions were nausea and an increase in transaminases. The SPC states that the risk of bleeding may be increased in certain patient groups, for example those with uncontrolled severe arterial hypertension and/or those taking other treatments that affect haemostasis. For full details of side effects and contraindications, see the SPC.
2.3 Rivaroxaban costs £45.00 for a pack of ten 10-mg tablets (£135.00 for 30 tablets), excluding VAT (NHS list price as reported by the manufacturer). The cost of treatment is estimated to be £63.00 (based on 14 tablets over 2 weeks) for knee replacement surgery and £157.50 for hip replacement surgery (based on 35 tablets over 5 weeks). Costs may vary in different settings because of negotiated procurement discounts.