US FDA curbs use of high-dose simvastatin, citing increased risk of muscle injury

The US Food and Drug Administration yesterday announced safety label changes for the cholesterol-lowering drug simvastatin, the now off patent once blockbuster drug Zocor from Merck & Co (NYSE: MRK), because the highest approved dose - 80mg -has been associated with an elevated risk of muscle injury or myopathy, particularly during the first 12 months of use.

The agency is recommending that simvastatin 8mg be used only in patients who have been taking this dose for 12 months or more and have not experienced any muscle toxicity. It should not be prescribed to new patients. There are also new contraindications and dose limitations for when simvastatin is taken with certain other medications.

In 2010, about 2.1 million patients in the USA were prescribed a product containing simvastatin 80mg, the FDA noted, which Merck pointed out is just around 12% of simvastatin users in the USA. Simvastatin is also a component of Vytorin (ezetimibe/simvastatin), another cholesterol-lowering medicine from Merck, and is sold by Abbott Laboratories in combination with niacin as Simcor. According to IMS Health data, simvastatin, including all dose strengths, was the second-most prescribed drug in the USA last year.