FDA Heightens Concern about Zocor Dosage, Potential for Myopathy

Washington, DCZocor simvastatin has long been linked to various side effects such as muscle and liver damage, but the US Food and Drug Administration (FDA) recently strengthened the warning with regard to myopathy, or muscle injury. According to the 3/19/10 FDA news release, statins such as Zocor carry a higher risk of injury when taken at doses exceeding 40 mg in concert with certain other medications.


It's not just Zocor that's the culprit—all drugs in the statin family carry a risk of myopathy. The FDA is particularly concerned about the potential for rhabdomyolysis, one of the most serious forms of myopathy, which can lead to severe kidney damage, kidney failure and in some cases even death.

In comments to be published in the 4/11/10 issue of the Medical Letter on the CDC and FDA, Dr. Eric Colman, MD, Deputy Director of FDA's Division of Metabolism and Endocrinology Products (DMEP), said, "Review of simvastatin is part of an ongoing FDA effort to evaluate the risk of statin-associated muscle injury and to provide that information to the public as it becomes available. It's important for patients and healthcare professionals to consider all the potential risks and known benefits of any drug before deciding on any one therapy or dose of therapy."

The FDA is studying data from the Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine, otherwise known as the SEARCH trial, which evaluated major cardiovascular events such as heart attack, revascularization and cardiovascular death in patients taking 20 to 80 mg of simvastatin. SEARCH also included data on muscle injury in patients taking simvastatin.

Further complicating matters is the fact that simvastatin is available as a single-ingredient generic medication (Zocor), but it is also found in Vytorin along with ezetimbe—and it is teamed with niacin in Simcor.

The FDA notes that 80 mg is the highest approved dose for the cholesterol-busting drug. The agency also advises patients to limit their intake of simvastatin to 40 mg when taking other medications simultaneously, noting with concern that patients "are continuing to be prescribed higher doses of simvastatin with other medications that are known to increase the risk for rhabdomyolysis."