Xarelto, Pradaxa Monitoring Pointless Because Manufacturers Did Not Adequately Research: Aussie Regulators

Foreign regulators are raising questions about whether additional blood monitoring for Xarelto, Pradaxa, Eliquis or other new-generation anticoagulants would make the drugs any safer, since the manufacturers have failed to conduct sufficient research on the controversial medications. 

Xarelto, Pradaxa and Eliquis are all part of a new breed of blood thinners prescribed to prevent blood clots among patients with atrial fibrillation and other circumstances where users face a risk of deep vein thrombosis (DVT), pulmonary embolism or stroke.

The medications have quickly grown to become blockbuster treatments following aggressive promotions by the drug makers, which indicate the medications are easier to use since they do not require the close blood monitoring necessary with warfarin, which has been the go-to anticoagulant for decades.

Since the drugs have hit the market, a surprising number of reports involving severe and uncontrollable bleeding problems have surfaced with Xarelto, Pradaxa and Eliquis, raising serious questions about the safety of the medications and the adequacy of warnings provided by the drug makers.

The Australian Therapeutic Goods Administration announced earlier this month that it has completed a review of new oral anticoagulants (NOACs), which found that there is no evidence to support routine blood monitoring at this time. However, the report indicated that the reason blood monitoring is unlikely to make the drugs safer is because the manufacturers have failed to tests whether monitoring would help, creating a lack of usable data.

“The NOAC sponsors have not undertaken dedicated studies to evaluate the effects of routine plasma monitoring on the safety profile of their medicines, as such monitoring is not likely to significantly add to the use of clinical parameters to determine bleeding risk,” the TGA statement indicates. “Therefore, the TGA’s review has found there is no evidence at this time to support a recommendation for routine plasma monitoring in patients being treated with these medicines.”

The TGA review comes after thousands of Xarelto lawsuits and Pradaxa lawsuits have been filed against the drug makers in the U.S., alleging that inadequate warnings were provided about the potential bleeding risk and the lack of an effective reversal agent that doctors could use to stop bleeds that develop. Many of the complaints also allege that the drug makers should have recommended blood monitoring, which could have allowed doctors to adjust the dose based on test results to avoid high concentrations that may lead to serious bleeding events.

New Blood Thinner Bleeding Risks

Pradaxa was introduced by Boehringer Ingelheim in late 2010 as the first member of a new class of anticoagulants. Xarelto was introduced by Bayer and Janssen Pharmaceuticals in 2011, as the second member of this class.

While all blood thinners carry a risk of bleeding injury, Pradaxa and Xarelto have been linked to a surprising number of problems as more and more patients are switched from warfarin to the new anticoagulants.

Unlike warfarin, where doctors can quickly reverse the blood thinning effects of the medication if bleeding problems develop, Pradaxa and Xarelto were introduced without an effective reversal agent. As a result, many doctors have reported being unable to stop or control hemorrhaging or bleeding that develops among users of the drugs.

Several recent studies have also raised questions about the marketing claims made by the makers of these new anticoagulants, suggesting that Pradaxa and Xarelto blood monitoring may actually help doctors identify patients at the greatest risk of bleeding.

In July 2014, an investigative report published by The BMJ suggested that the makers of Pradaxa failed to provide the FDA with important clinical trial data that suggested users may benefit from regular blood monitoring to make sure the drug did not build up in their bloodstream, increasing the risk of bleeds.

In to another study published by the Journal of Cardiology in October 2014, researchers indicated that Xarelto monitoring may have helped doctors understand the effects of the drug on a particular patient and their associated bleeding risk.