Xarelto, one of the newer generation of blood thinners, was approved by the FDA in 2011. It’s making news lately — and not for good reason. Lawsuits alleging rivaroxaban (Xarelto) harms — or even kills — keep piling up. Moreover, the FDA has concerns about the testing device used in the clinical trials that led to approval of the drug.
If you’re taking this anticoagulant or one of its cousins — apixaban (Eliquis), edoxaban (Savaysa) and dabigatran (Pradaxa) — that are mainly prescribed to treat atrial fibrillation to prevent blood clots potentially causing a stroke, should you continue? While many doctors say yes, knowing more about the problems associated with the drug is still a wise idea.
The FDA and the European Medicines Agency (EMA) have lately been reviewing the key clinical trial submitted to the FDA that found Xarelto as safe or safer than warfarin. Warfarin (Coumadin), had been the gold-standard blood thinner for generations.
The study’s results were substantially based on the results of INR testing, as measured by a device called INRatio. INR measures the effectiveness of the anticoagulant (blood thinner) in the bloodstream. The INRatio device was subject to an FDA recall and voluntary “correction,” meaning the results of the device should not be trusted.
A Faulty Testing Device
In the most recent update, the EMA concluded that while the INRatio device was indeed faulty, the trial’s results remain sound.
“Of course that’s concerning and these medications are not without risk,” says Jonathan Hsu, MD, cardiologist and assistant clinical professor of medicine at the University of California, San Diego. While there are risks to any medication, he says, there are also patients for whom these meds have been a literal life saver, by preventing stroke, for example.
Warfarin, adds Edith A. Nutescu, PharmD, associate professor of pharmacy systems, outcomes and policy at the University of Illinois at Chicago, should still be relied on as a first-line alternative. But, “rivaroxaban is favored in those cases where the laboratory testing and monitoring necessary for warfarin is an inconvenience for the patient.”
Clinical trial data puts a question mark on the newer drug’s use for the prevention of atrial fibrillation, she says, but Xarelto is also approved to help prevent or treat venous thromboembolism (VTE), which is a potentially dangerous blood clot.
“While providers may be reluctant to prescribe Rivaroxaban for atrial fibrillation until outside researchers or entities not funded by the manufacturer confirm the clinical trial results, rivaroxaban still provides a great alternate option in the treatment of patients with VTE,” says Nutescu.
Thousands of Lawsuits Pending
Still, thousands of lawsuits are pending, alleging the drug has caused serious injuries and/or death. Patients, the suit says, should have been warned about the drug’s risks, and the need for dose adjustments and blood monitoring.
Despite the allegations, Dr. Hsu says the drug has its merits.
“What [the researchers] found is these agents in general appear as safe as warfarin and in some areas may have a lower risk of bleeding, particularly in the brain,” Hsu says, which had been many patients’ biggest concern. But, he adds, a major concern with Xarelto is that there’s no current FDA-approved antidote for uncontrollable bleeding (although one is likely to be approved soon).
For any serious bleeding — for example, if you feel light-headed and/or have profuse bleeding, Dr. Hsu recommends applying pressure directly to the site of the bleeding if possible, and seeking medical care immediately to determine whether you should or should not take your next scheduled dose of the drug. But if the bleeding is more of a nuisance — say, you cut yourself and it seems to take some time to stop the bleeding but you otherwise feel fine — he advises patients to stay on the drug, and consult your doctor.
“We need to ensure that the medication is selected and prescribed appropriately, and patients taking the medication need to be educated and appropriately monitored for factors that can alter the risk/benefit profile, such as pertinent drug-drug interactions, changes in renal [kidney] function, changes in liver function and patient adherence,” adds Nutescu.
Meanwhile, researchers with the Duke Clinical Research Institute (who oversaw the original trial) published a letter in the New England Journal of Medicine affirming that even though there were some problems with the trial’s monitoring device, these didn’t affect the trial’s outcome. And yet, questions remain.
“Any drug can have potentially life-threatening side effects,” notes Hsu, who says these should be scrutinized. But overall, he contends? The benefits still outweigh the risks.
- Why File a Xarelto Lawsuit? (DrugWatch.com)
- Blood Thinner Pills: Your Guide to Using them Safely (AHRQ.gov)