In October 2012, the Institute for Safe Medication Practices (ISMP) published a study reviewing the approval of rivaroxaban, Xarelto’s scientific name, by the U.S. Food and Drug Administration (FDA) for short-term treatment of venous and pulmonary embolisms (blood clots) for patients undergoing joint replacement surgery. The ISMP concluded orally ingested blood thinners were “among the riskiest of all outpatient drug treatments” due to high instances of internal bleeding.
During FDA trials, the study found that 15% of 14,000 patients experienced some form of internal bleeding. Despite this risk, the FDA approved Xarelto for both short-term blood clot prevention and long-term use to prevent stroke in patients with abnormal heartbeats.
FDA review teams recommended against approving Xarelto as a long-term treatment for the prevention of stroke and questioned the once-a-day dosing regimen for the drug, noting a twice-daily dose of the medication could eliminate the spikes and dips of the medication in a patient’s bloodstream. The review teams were overruled by an advisory committee and senior FDA management.
The study found 356 serious injury events in the first quarter of 2012 where Xarelto injuries were believed to be the underlying cause, up 178% from 128 cases in the previous quarter. The ISMP study found that of the 356 cases investigated in its 2012 findings, 44% suffered the same blood clots Xarelto was prescribed to prevent. These blood clots were primarily reported in patients taking Xarelto after undergoing joint replacement and orthopedic surgeries where the median patient age was 66 years.
The 2012 ISMP study discovered that internal bleeding events in blood-thinning medications similar to Xarelto like dabigatran (Pradaxa), warfarin, and enoxaparin outnumber internal bleeding events attributable to Xarelto. But Xarelto resulted in a significantly higher occurrence of blood clots and strokes compared with the other medications. The ISMP suggested that the higher rate of blood clots with Xarelto could be attributed to inadequate dosage levels prescribed to patients after surgeries.
In May 2014, the ISMP published another report on rivaroxaban (Xarelto) with new data collected from the first quarter of 2013. This study revealed a positive correlation between the increase of Xarelto prescriptions and serious adverse health events. The report also demonstrated that strokes and internal bleeding events rose as Xarelto prescriptions increased. The 2014 ISMP report also suggested a link between patients experiencing post-surgery blood clots and an insufficient dose of Xarelto prescribed to them.