SP: Why is the FDA recommending limits on Zocor (simvastatin)?
The FDA is recommending limiting the use of the highest approved dose of the cholesterol-lowering medication, simvastatin (80 mg) because of an increased risk of muscle damage. This determination was made after a comprehensive review of the results of the Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) clinical trial, other large clinical trials of high-dose statins, and the FDA's Adverse Event Reporting System (AERS). The data shows that there is a higher risk of myopathy, including rhabdomyolysis, with simvastatin 80 mg relative to lower dose of simvastatin and to other statins of similar or greater LDL-lowering efficacy. The increased risk in SEARCH, however, was noted during the first 12 months of therapy, and was commonly associated with the use of medications such as amiodarone, diltiazem, and amlodipine. It was frequently associated with a genetic variant that predisposes to statin-associated myopathy. The intent of the limits were to restrict new initiators of simvastatin 80 mg, while ensuring that patients tolerating the dose do not unnecessarily stop it.
SP: What policy is being changed by the FDA?
Patients on simvastatin 80 mg may maintain this dosage only if they have been taking this dose chronically (e.g., for 12 or more months) without evidence of muscle toxicity. Patients who do not meet their LDL cholesterol (LDL-C) goal on simvastatin 40 mg should be placed on alternative LDL-C lowering treatment(s) that provides greater LDL-C lowering. Patients currently tolerating the 80-mg dose who need to be initiated on an interacting drug that is contraindicated or associated with a dose cap for simvastatin should be switched to an alternative statin with less potential for the drug to drug interaction.
SP: What are the new labeling changes?
The FDA has revised the drug labels for simvastatin and Vytorin to include the new dosing restriction for the 80-mg dose. The labels for simvastatin, Vytorin, and Simcor were also revised to include new dosing recommendations when these drugs are used with certain medicines that interact with simvastatin to increase the level of simvastatin in the body. Increasing the levels of simvastatin in the body can increase the risk for myopathy.
To learn more about the simvastatin guidelines, visit the consumer update here.
Image: via flickr, Common Pixel