Friday, June 27, 2008

An oral anticoagulant in the pipeline

Rivaroxaban (Xarelto), an oral direct factor Xa inhibitor, was superior to enoxaparin (Lovenox) for VTE prophylaxis in patients undergoing hip and knee arthroplasty according to two NEJM reports this week.

These studies leave questions. First, the investigators may merely have defeated the following straw man: Lovenox is the best agent for VTE prevention when used at less than the recommended dose. That’s right, the lovenox dose for the comparison groups (40 mg daily) was below that which is recommended in the product labeling (30 mg Q 12 hours) for these indications.

The bigger question on every one’s mind is whether it will replace warfarin, with the promise of reduced laboratory monitoring. That answer awaits studies on patients with atrial fibrillation and established VTE, early in the game at present. Don’t expect warfarin to disappear from the planet anytime soon.

Other blog reactions:

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Retired Doc
Image source: Wikipedia


Anonymous said...

Good point about the dose of enoxaparin.I need to say more about that having made points about stacking the deck in randomized trials.Is that what we have here?

Robert W Donnell said...

This may be about stacking the deck. Your comment raises a larger point which I have addressed in a follow up post.

Anonymous said...

I just came across this post from months ago. As the blogger has likely realized, the 40mg once daily dose is the standard European regimen, which is started pre-operatively (as opposed to the 30mg bid started post operatively in the US).

The U.S. regimen is being used in RECORD4, which is ongoing