A French study shows that the risk of life threatening or uncontrollable bleeding events in patients using Xarelto are no greater than that in patients using Warfarin. However, the study warns that the fact that no reversal agent exists for the effects of Xarelto does not make it safer than Warfarin.
Next generation blood thinners have been in the news a lot recently due to claims that the risk of serious bleeding events is greater than tried-and-true Warfarin. However, a new study published in the July issue of the Circulation journal suggests that Xarelto bleeding risks equal to Warfarin.
The study examined instances of adverse events such as internal bleeds, heart attacks and strokes. The National Health Insurance Strategy and Research Department in France conducted the study using data from 19K Warfarin patients, 8K Pradaxa patients and 5K Xarelto patients. Researchers were concerned with drug safety particularly during the initial phases of treatment. The patients were taking blood thinners as preventative measures against stroke due to nonvalvular atrial fibrillation.
The study’s findings indicate that, in the first three months of treatment, there was no difference in the number of bleeding events between the three groups. However, the researchers do not insist that this lends credence to manufacturer’s claims that Xarelto is safer than Warfarin. This is largely due to the fact that there is no known reversal agent for the blood thinning effect of Xarelto.
“NOAC [Xarelto] cannot be considered to be safer than VKA [Warfarin] during the early phase of treatment. On the contrary, the clinical implications of our results are that physicians must be just as cautious when initiating NOAC as when initiating VKA, particularly in view of the absence of an antidote and objective monitoring of the extent of anticoagulation.”
This is a responsible conclusion to reach. Warfarin bleeds, even those that are life threatening, can be counteracted with a dose of vitamin K. While the incidents of bleeds may be similar between Warfarin and Xarelto, those caused by Xarelto are ultimately more dangerous to patients.
Xarelto marketing focuses on the claim that it’s safer than Warfarin, a claim cast into doubt by this study due to the lack of a reversal agent. The drug was aggressively marketed as not only safer, but more convenient than Warfarin. Patients on Warfarin must deal with dietary restrictions and frequent blood tests. Xarelto does away with these requirements. However, the monitoring may actually have the benefit of reducing the risk of bleeding events.
There are currently a number of suits against Bayer and Janssen, Xarelto’s makers, over uncontrollable and/or life threatening bleeding events. A multi-district litigation (MDL) was created in December 2014 to consolidate these suits. As of this month, 500 suits have been consolidated under the MDL in U.S. District Court for the Eastern District of Louisiana.