Report: Pradaxa tops FDAs list for serious adverse events
Dabigatran topped the list of direct reports to the FDA of serious adverse drug events in 2011, according to an analysis by the Institute for Safe Medication Practices. Dabigatran (Pradaxa, Boehringer Ingelheim) had the largest number of direct reports, at 817, followed by warfarin, at 490.

Reports from both the manufacturer and direct reports pointed to 3,781 serious adverse events associated with dabigatran in the U.S. in 2011, according to the analysis. Analysts identified 542 patient deaths, 2,367 cases of hemorrhage, 291 cases of acute renal failure, 644 cases of stroke and 15 cases of suspected liver failure. The FDA approved the use of dabigatran for the prevention of stroke and systemic embolism in non-valvular AF patients in 2010.

Warfarin had 1,106 cases overall in 2011, including 72 deaths. The authors noted that in past analyses, warfarin consistently ranked near the top for direct reports to the FDA.

“Two drugs that inhibit the formation of blood clots ranked first and second among all direct reports to the FDA in 2011, emphasizing that the combination of a vulnerable patient population and a powerful pharmacological action rank among the highest risks in prescription drug therapy,” the authors wrote in the report, QuarterWatch. “While a therapeutic goal of preventing strokes, pulmonary embolism, and other harm through unwanted blood clots is a worthy objective, these results demonstrate that treatment is accompanied by substantial risks.”

The European Medicines Agency (EMA) reported May 25 that its post-marketing data on dabigatran showed that the frequency of occurrence of fatal bleedings was significantly lower than what was observed in clinical trials. Nonetheless, the EMA called for an update of product information to give physicians clearer guidance on how to reduce and manage the risk of bleeding.

By QuarterWatch’s count, the FDA received 179,855 reports of serious, disabling and fatal adverse drug events in the U.S. in 2011, an increase of 9.4 percent from 2010. The majority, 88 percent, were submitted by drug manufacturers while the remaining 12 percent were submitted to the FDA by health professionals and patients.

In a section on suspect drugs linked to severe side effects in the U.S., the report listed simvastatin (Zocor, Merck) and rosuvastatin (Crestor, AstraZeneca) as first and second most frequently identified drugs linked to severe muscle damage in 2011. Simvastatin had 123 cases and rosuvastatin 73 cases. By contrast, atorvastatin (Lipitor, Pfizer) accounted for only 15 reported cases.

QuarterWatch is published by the Institute for Safe Medication Practices, a Horsham, Pa.-based nonprofit organization that monitors adverse drug events reported to the FDA. The QuarterWatch reports are funded through the institute and are based on analyses of computer excerpts that the agency releases for research use from its Adverse Event Reporting System.

The report was published May 31 and is available here.