Simvastatin (marketed as Zocor; also an ingredient in Vytorin and Simcor) is a cholesterol-lowering drug. Merck obtained approval by the FDA in 1991 and it was their largest selling drug prior to the loss of patent protection in early 2006. Zocor was also the second largest selling cholesterol-lowering drug in the world. Merck recorded $4.3 billion in sales for Zocor in 2005. Generic sales began in June 2006. The FDA estimates that over 2 million people were prescribed simvastatin 80 mg in 2010.
A new study shows that 80 mg doses of simvastatin can increase the risk of muscle damage. This has prompted the FDA to revise prescribing information for simvastatin 80 mg, stating that it should not be started in new patients and should not be used in combination with certain drugs.
Patients taking simvastatin 80 mg daily have an increased risk of myopathy (muscle damage, pain, tenderness or weakness, and an elevation of a muscle enzyme in the blood, dark or red-colored urine, fatigue). The most serious form of myopathy is rhabdomyolysis, which results in kidney damage and/or kidney failure.