(June 25, 2008 - Insidermedicine) A direct inhibitor of factor Xa that can be taken orally offers superior protection against thrombotic events following total hip arthroplasty than enoxaparin, according to research in the New England Journal of Medicine.

The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy recommends the following after elective hip arthroplasty:

•    Low molecular weight heparin, at a usual high-risk dose, started 12 hours before surgery or 12 to 24 hours after surgery, or 4 to 6 hours after surgery at half the usual high-risk dose and then increasing to the usual high-risk dose the following day.

•    Fondaparinux, 2.5 mg started 6 to 8 hours after surgery.

•    Adjusted-dose vitamin K antagonist, started preoperatively or the evening after surgery.

Researchers out of Sahlgrenska University Hospital in Gothenburg randomized over 4,500 patients who underwent total hip arthroplasty to treatment with 10 mg of oral rivaroxaban or 40 mg of enoxaparin delivered by subcutaneous injection. The patients received the treatment once daily, starting after surgery.

Use of rivaroxaban was associated with an absolute risk reduction of 2.6% for the composite endpoint of deep vein thrombosis, nonfatal pulmonary embolism, or death from any cause at 36 days. Rates of major bleeding were similar for both groups.

We had a chance to speak with Dr. Richard Becker from Duke University, who wrote an editorial on this study and offered us some further insight.

Today's research demonstrates that rivaroxaban offers superior convenience and efficacy with a similar safety profile compared with enoxaparin following hip arthroplasty.

For Insidermedicine in Depth, I'm Dr. Susan Sharma.