The risk of rhabdomyolysis associated with use of atorvastatin, pravastatin, and simvastatin is relatively low for most patient subgroups, according to an article in the December 1st issue of the Journal of the American Medical Association.

However, data analysis showed that older patients with diabetes who received combined statin-fibrate therapy may be at increased risk for rhabdomyolysis, and patients who were taking cerivastatin combined with fibrates had a significantly higher risk − roughly one in 10 treated patients each year. Cerivastatin was removed from the U.S. market in 2001 because of reports of rhabdomyolysis associated with its use.

Disorders of muscle are among the most discussed adverse effects associated with the use of statins, according to background information in the article. Fibric acid derivatives (fibrates) have also been associated with primary muscle injury, especially when used in combination with a statin.

David J. Graham, MD, MPH, from the Food and Drug Administration, and his American colleagues analyzed claims data from 11 managed care health plans across the United States for patients on statins alone (monotherapy) or combined statin-fibrate therapy between January 1, 1998 and June 30, 2001.

“In 252,460 patients treated with lipid-lowering agents, 24 cases of hospitalized rhabdomyolysis occurred during treatment,” the researchers reported. All patients with rhabdomyolysis were taking statins at daily dosages within the dose-range recommended in product labeling. “Compared with statin monotherapy, fibrate use was associated with a 5.5-fold increase in risk and the combined use of a statin and fibrate increased risk by additional 2-fold versus fibrate alone,” the authors found. “The risk of rhabdomyolysis with cerivastatin monotherapy was 10-fold greater than with other statins, and in combination with a fibrate, was increased more than 1,400-fold.”

The authors wrote, “With the potential for substantial increase in the number of patients treated with statins over the next several years, our study provides reassurance that the risk of rhabdomyolysis is relatively low with three frequently prescribed statins. For patients treated with both statins and fibrates combined, such as persons with diabetes mellitus with elevated cholesterol and triglyceride levels, the higher risk conferred by combination therapy may warrant that physicians instruct their patients to stop therapy and be evaluated if symptoms suggestive of rhabdomyolysis develop.”