Harvard Health Letter

Antidote for blood thinner's side effect

There's encouraging news for people who take dabigatran (Pradaxa), a newer type of blood thinner that's had a rare side effect of uncontrolled bleeding during surgery or accidents. In October 2015, the FDA approved an antidote called idarucizumab (Praxbind), which may be able to reverse dabigatran's blood-thinning effects.

Dabigatran was approved by the FDA in 2010 and welcomed as a convenient alternative to warfarin (Coumadin) for people with certain types of atrial fibrillation, deep-vein thrombosis, or pulmonary embolism. While warfarin is generally safe and inexpensive, it takes about a week for it to become effective, and dosing is so complicated that people taking warfarin need frequent blood tests to see if the dose needs to be adjusted. Dabigatran is effective within two hours and doesn't require dose adjustment or lab monitoring. But dabigatran has caused more episodes of major bleeding than had been expected, without a way to reverse the problem.

Idarucizumab, given by injection, appears to stop the effect of dabigatran and allow the blood to clot. Meanwhile, antidotes are also in the works for three other blood thinners that were approved after dabigatran, including rivaroxaban (Xarelto), apixaban (Eliquis), and edoxaban (Savaysa).