Researchers working on antidote for yet-to-be approved blood thinner
Apixaban (Eliquis), a new blood thinner currently under review for stroke prevention in patients with atrial fibrillation, offers one benefit newly approved anticoagulants do not – approaches to reverse the action of the drug.
Blood thinners are routinely prescribed to prevent and treat blood clots in patients, and each carries a risk for internal bleeding. Warfarin, which was approved more than 50 years ago, is one of the most commonly used blood thinners for atrial fibrillation. But because the bleeding risk is so great with the drug, patients have to be monitored on a regular basis. If hemorrhage occurs, there are antidotes doctors can use to stop the bleeding.
In 2010, the Food and Drug Administration (FDA) approved Pradaxa for stroke prevention in atrial fibrillation patients. Last year, the FDA also cleared Xarelto for the same indication. The agency had high hopes that the drugs would be safer alternatives to warfarin, but early reports look bleak.
Pradaxa was linked to serious and sometimes fatal bleeding events. It is still too early to determine the risks with Xarelto. A major drawback is that there are no reversal agents for Pradaxa or Xarelto, though the makers of Xarelto say they are working on one.
News that antidotes exist for the experimental Apixaban could help the drug’s chances of being approved by the FDA. Currently, researchers say there are three different approaches that can be taken to reverse the effects of Apixaban. Studies are currently being performed to determine the best one to use.
“The good news is that the various lab tests indicate that these approaches may reverse the effects of Apixaban,” concluded Dr. Gines Escolar, the study’s author. “But even with the favorable results in perfusion (restoration of blood flow) studies using a damaged vessel, we’re far from knowing what will work best in a bleeding patient. Resolving efficacy and safety issues will require a clinical trial.”
Apixaban is already approved in Europe for preventing blood clots in adults after knee or hip replacement surgery.
Source: Doctors Lounge