Breaking News: FDA issues new dosing limitations for Simvastatin

June 10, 2011

By Saleem Ali, MD

The FDA has issued new warnings regarding the use of high dose Simvastatin. The FDA is now recommending that the 80mg dose only be used in patients who have been taking that dosage for at least 12 months with no signs of toxicity.  Patients who are currently on simvastatin and require more than 40 mg. should be considered for alternative lipid lowering therapy. The FDA is issuing this warning because recent data has shown that the 80 mg. dose has a significantly higher risk of rhabdomyolsysis and muscle injury than lower doses.

Leading to this alert was a preliminary analysis of the Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) trial.  The purpose of this randomized controlled trial was to determine if more intensive lipid lowering therapy would prevent future cardiac events. Over 12,000 patients with a prior myocardial infarction were randomized to 80 mg. vs. 20 mg. of Simvastatin and then followed for an average of 6.7 years. Myopathy developed in 52 (0.9%) in the 80 mg. group  vs 1 (0.04%) patients in the 20 mg. group.   Rhabdomyloysis developed in 11 (0.2%) cases in the 80mg group vs. 0 in the 20mg group.

Providers are also reminded to be aware of the many drug interactions with simvastatin.  Please see the alert below to review those interactions and recommendations for dosing.