FDA Drug Safety Communication

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FDA Date: 6/8/11

FDA Drug Safety Communication for Zocor (simvastatin)

New Restrictions, Contraindications, and Dose Limitations for Zocor (simvastatin) to Reduce the Risk of Muscle Injury

FDA is recommending limiting the use of the highest approved dose of the cholesterol-lowering medication simvastatin (80 mg) because of increased risk of muscle damage. Simvastatin 80 mg should be used only in patients who have been taking this dose for 12 months or more without evidence of muscle injury (myopathy). Simvastatin 80 mg should not be started in new patients, including patients already taking lower doses of the drug. In addition to these new limitations, FDA is requiring changes to the simvastatin label to add new contraindications (should not be used with certain medications) and dose limitations for using simvastatin with certain medicines.

Patients taking simvastatin 80 mg daily have an increased risk of myopathy compared with patients taking lower doses of this drug or other drugs in the same class. This risk appears to be higher during the first year of treatment, is often the result of interactions with certain medicines, and is frequently associated with a genetic predisposition toward simvastatin-related myopathy. Patients with myopathy generally have muscle pain, tenderness, or weakness, and an elevation of a muscle enzyme in the blood (creatine kinase, or CK). The most serious form of myopathy, called rhabdomyolysis, can damage the kidneys and lead to kidney failure which can be fatal. Rhabdomyolysis is rare; hospitalized rhabdomyolysis occurs in 4.9 people out of every 100,000 people exposed to simvastatin for one full year (the average incidence for hospitalized rhabdomyolysis for atorvastatin, pravastatin, or simvastatin is 4.4 people out of every 100,000 people).

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.

View the full FDA Drug Safety Communication on FDA.gov