Pradaxa Bleeding Side Effects May Be Stopped By Reversal Agent: Study

The makers of the controversial anticoagulant Pradaxa indicate that they may have found an effective reversal agent, which could help doctors rapidly counteract the blood thinning effects of the drug and stop potentially life-threatening bleeding problems that develop among users.  

A study on the potential Pradaxa reversal was presented on Sunday at the American College of Cardiology’s annual scientific session.

European researchers backed by the drug maker Boehringer Ingelheim indicated that a humanized antibody fragment may be the antidote doctors have sought for uncontrolled Pradaxa bleeding side effects since the anticoagulant was first introduced in October 2010.

The potential reversal agent, idarucizumab, also known as aDabi-Fab, was tested on 24 male pigs who were given Pradaxa for three days and the results were compared to six pigs who were given a placebo. All of the pigs who suffered a bleeding event caused by trauma after receiving the placebo died. Those who were given aDabi-Fab as an antidote saw a significant and dose-dependent drop in bleeding. Mortality among those pigs was only 17%.

Researchers had to obtain ethical approval for the experiments, which required the pigs undergo blunt liver injury, trauma and blood loss.

Speculation about aDabi-Fab’s potential use as a Pradaxa reversal agent has circulated since 2013.

Pradaxa Litigation Over Bleeding Problems

Pradadxa (dabigatran) is a relatively new anticoagulant therapy that was approved by the FDA in 2010, as the first member of a new class of medications that are promoted as superior alternatives to warfarin for stroke prevention. However, shortly after its introduction, Pradaxa began to rack up a record number of adverse event reports after patients experienced uncontrolled bleeding events.

Warfarin, sold under the brand name Coumadin, has been the go-to anticoagulant for decades. While Pradaxa was promoted as easier to use, because it requires less monitoring by the doctor during treatment, concerns have emerged about the lack of an effective reversal agent to stop the blood thinning effects of the medication.

Unlike warfarin, which can be quickly reversed with a dose of vitamin K and plasma, there is no available reversal agent for Pradaxa. While some studies have shown that the chances of bleeding may be about the same with the two drugs, evidence continues to emerge highlighting how Pradaxa bleeding problems may pose a more serious risk, since hemorrhages are typically harder to stop.

There have been thousands of reports of injuries and hundreds of deaths associated with Pradaxa use since it was introduced in October 2010.

The findings come as Boehringer Ingelheim faces more than 2,000 Pradaxa bleeding lawsuits brought on behalf of individuals throughout the United States who allege that the drug maker failed to adequately warn about the risks associated with the anticoagulant and the lack of an effective reversal agent, which has left many doctors unable to control hemorrhages that may develop during treatment.

All federal complaints have been centralized before U.S. District Judge David R. Herndon in the Southern District of Illinois for coordinated handling as part of an MDL, or multidistrict litigation. The first Pradaxa trials are expected to begin later this year, with a series of four “bellwether” cases set to go before juries between September 2014 and March 2015.