The Food and Drug Administration on Friday warned patients and healthcare providers that Merck & Co. Inc.'s (MRK) highest approved dose of cholesterol-lowering medication Zocor (simvastatin) 80 mg could cause harm to muscles.
Zocor, which lost exclusivity in June 2006, is sold as a single-ingredient generic medication and as the brand-name Zocor. The drug is sold in combination with ezetimibe as Vytorin, and in combination with niacin as Simcor.
The regulatory agency in a statement noted that "although muscle injury (called myopathy) is a known side effect with all statins, the current warning highlights the greater risk of developing muscle injury, including rhabdomyolysis, for patients when they are prescribed and use higher doses of this drug". Rhabdomyolysis is the most serious form of myopathy and can lead to severe kidney damage, kidney failure, and sometimes death.
The FDA said that the new information on the risk of muscle injury is derived from clinical trials, observational studies, adverse event reports, and prescription use data.
In addition, the FDA is reviewing data from the SEARCH (Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine) trial, which evaluated major cardiovascular events, such as heart attack, revascularization and cardiovascular death, in patients taking 80 mg compared to 20 mg of simvastatin. SEARCH also included data on muscle injury in patients taking simvastatin.
MRK closed Friday's trading at $38.06, down 1.01%, on a volume of 30 million shares. In after-hours trading, the stock further lost 0.39% and was at $37.91.
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