One of the concerns with the newer class of oral anticoagulants, such as dabigatran, is the lack of a reversal antidote. Now, researchers are developing new blood thinners and antidotes back to back.
In this case, Duke researchers in the lab first isolated a modified RNA aptamer (RNAR9D-14T) that proved to be a potent anticoagulant, and then they developed an antidote -- several, in fact -- for reversibility.
The new anticoagulant inhibits both thrombin generation and other thrombin-mediated activity, such as fibrin clot formation and platelet activation, with high affinity, Bruce Sullenger, PhD, and colleagues reported online in the Journal of Thrombosis and Haemostasis.
More importantly, perhaps, is the simultaneous development of several complementary oligonucleotide antidotes (the anticoagulant is string of 58 nucleotides) that can reverse the anticoagulant mechanism, and do so rapidly -- in under 2 minutes -- and for a durable period of time (longer than two hours).
When they compared the new anticoagulant with another investigational agent called ARC-183, they found that RNAR9D-14T was much more specific, making it a more robust anti-clotting agent.
But the modified RNA aptamer is not quite ready for prime time. Sullenger and colleagues said that future research should try to further modify the drug so that a smaller dose can be used without losing potency. Also, in vivo studies still need to be conducted.
Dabigitran is Pradaxa, which is sometimes prescribed after CCSVI treatment to prevent clotting. If it does not have a reversal antidote, then the doctors have to wait for it to wear off? The research into anticoagulants that have reversal antidotes looks promising. Hopefully the in vivo studies will look at this in veins and not just arteries.