The new oral anticoagulants apixaban, rivaroxaban and edoxaban (factor Xa inhibitors) are effective blood thinners. But an important clinical limitation is that, unlike warfarin, there is no antidote in the event of haemorrhage.
But now, the results of two placebo-controlled trials, published in the New England Journal of Medicine (online, 11 November 2015)
, show that the inactive recombinant factor Xa protein andexanet can reverse the anticoagulant effects of factor Xa inhibitors.
Andexanet administration reduced anti-factor Xa activity by 94% and 92% in healthy volunteers who had received apixaban or rivaroxaban, respectively. Thrombin generation was fully restored in 100% and 96% of participants, respectively, and the effects were observed within two to five minutes.
The researchers say that andexanet could provide a rapid antidote to factor Xa inhibitors for patients who experience bleeding or need emergency surgery.
- This article was amended on the 23 November 2015 to correct a previous version that erroneously included dabigatran as a factor Xa inhibitor rather than edoxaban.