Findings culled from a new method for aggregating and making sense of data in the FDA’s Adverse Event Reporting System (AERS) present a surprising glimpse at the postmarketing adverse event data for statins.

The study, which was conducted by AdverseEvents, Inc., using their proprietary new data sourcing method, RxFilter, found a class-wide variation in muscle-related adverse event reports. The results linked rosuvastatin (Crestor, AstraZeneca) with the highest percentage risk in 6 categories, including myopathy (general), myalgia, myositis, rhabdomyolysis, joints and tendons, muscle atrophy and injury, and muscle coordination and weakness. Pravastatin (Pravachol, Bristol-Myers Squibb) and lovastatin (Mevacor, Merck) demonstrated the best muscle-related safety profile.

“The results were surprising because in the literature it’s generally regarded that Crestor is very safe ... and Crestor, across the board, seemed to be linked to more adverse events in the categories that we searched than the other statin drugs, and so that was surprising,” said Keith Hoffman, PhD, vice president, Scientific Affairs, AdverseEvents, Inc.

Through RxFilter, the company identified more than 150,000 muscle-related adverse event reports in 6 categories linked to statins between January 1, 2004 and March 31, 2011. The drugs included atorvastatin (Lipitor), simvastatin (Zocor), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor), fluvastatin (Lescol), as well as generic equivalents and foreign designations. Percent risk calculations were determined based on the number of primary suspect adverse events linked to each statin, divided by an estimated number of patients exposed to the drugs during the study period. A ranked risk measure was used to calculate within-drug comparisons.

The results indicated that Crestor had the highest percent risk in each of 6 adverse event categories examined, while Pravachol and Mevacor appeared to have the least.

“We know there are limitations with the FDA AERS data, there’s no question,” Dr. Hoffman said. In their analysis, the company explored stimulated reporting as one potential bias, but did not see an increase in reports within the first 2 years of Crestor’s release.

“That makes us more comfortable that what we are showing might be a signal that doctors should pay attention to,” Dr. Hoffman said. “All we’re providing is the actual numbers, the actual case reports on what doctors themselves or patients reported for these side effects. At a base level it is the data that’s out there for post marketing; we’ve simply provided a way for people to see and look at those data.”

In their belief, Dr. Hoffman said, this is the first broad look at these postmarketing adverse events. Until now it has been very difficult to examine the AERS database. The company’s database is now online at www.adverseevents.com. Patients and healthcare providers can now search the data coming directly from AERS for more insight on the side effects that may be associated with specific drugs.

“The data presented in this report may offer important reference points regarding the selection of specific statins for cholesterol management in general and, especially, the rechallenge of patients that have experienced muscle-related side effects,” the company noted in conclusion to the study.