A phase III study has shown that for patients undergoing knee replacement surgery, oral rivaroxaban is better than subcutaneous enoxaparin at preventing blood clots (venous thromboembolism/VTE). The findings are reported in an Article published Online First and in an upcoming edition of The Lancet, written by Dr Alexander G G Turpie, McMaster University, Hamilton, Ontario, Canada, and colleagues.
Prophylaxis for VTE is recommended for at least 10 days after knee replacement surgery, and oral regimens could facilitate shorter hospital stays. In this randomised trial, the researchers analysed 3148 patients having knee surgery. Of these, 1924 were eligible for a direct comparison of the two drugs, with 965 patients receiving oral rivaroxaban 10 mg once daily, beginning 6-8 hours after surgery, and 959 receiving subcutaneous enoxaparin, starting 12-24 hours after surgery*. The primary outcome was any of blood clot in the leg, lung, or death. The researchers found that the primary outcome occurred in 7% of patients given oral rivaroxaban compared with 10% of those given subcutaneous enoxaparin — which translated to a 31% reduction in relative risk for patients given oral rivaroxaban.
The authors conclude: "Rivaroxaban, given as a once-daily 10 mg fixed dose 6 h postoperatively, is the first new oral anticoagulant to significantly reduce the incidence of VTE after total knee replacement surgery, compared with enoxaparin 30 mg twice daily, starting 12 h postoperatively, without a significant difference in the risk of major or clinically relevant bleeding."
In an accompanying Comment, Dr Richard C Becker, Duke University School of Medicine, Durham, NC, USA, says: "The overall effect of VTE after orthopaedic surgery is substantial. Accordingly, reducing the occurrence of VTE must continue to be a high priority in drug development, national health quality, best practice initiatives, and clinician-based patient care...oral drug delivery platforms could represent a vital step forward."
Dr Alexander G G Turpie, McMaster University, Hamilton, Ontario, Canada T) +1 905-929-4385 E) turpiea@mcmaster.ca
Dr Richard C Becker, Duke University School of Medicine, Durham, NC, USA T) +1 919-668-8926 E) richard.becker@duke.edu
For full Article and Comment, see: http://press.thelancet.com/record4.pdf
Note to editors: *12-24 hours post surgery is the currently approved regimen for enoxaparin, which is why this time window was used
Journal
The Lancet