The cholesterol-lowering drug Zocor (simvastatin) is being subjected to new restrictions and warnings because of its association with an elevated risk of muscle injury or myopathy. According to a statement from the U.S. Food & Drug Administration (FDA), the Zocor myopathy danger is most acute during the first 12 months a patient uses the statin. The most serious form of myopathy, called <"http://www.yourlawyer.com/topics/overview/rhabdomyolysis">rhabdomyolysis, can damage the kidneys and lead to kidney failure which can be fatal, the agency said.
The new restrictions and warnings also apply to <"http://www.yourlawyer.com/topics/overview/vytorin">Vytorin and Simcor, which are combination medications that include simvastatin as an active ingredient. Generic versions of simvastatin will also include the myopathy warnings and be subject to dosing restrictions.
Muscle aches are a well-known side effect of Zocor and other drugs in the same class, known as statins, and the labels for the class already bear warnings regarding this risk. In 2010, the FDA also issued a safety alert for high-dose simvastatin. According to a report from The New York Times, this latest action on the part of the FDA was prompted by a seven-year study and patient reports that prove those taking the higher dosage have a greater risk of muscle injury than patients treated with lower doses or other statins.
Symptoms of Zocor myopathy include:
â€¢ muscle pain, tenderness or weakness
â€¢ dark or red colored urine
â€¢ unexplained fatigue
â€¢ an elevation of a muscle enzyme in the blood (creatine kinase, or CK)
To mitigate the Zocor muscle injury risk, the FDA is recommending that the highest dose of the drug – 80 mg – not be prescribed to patients in their first 12 months of treatment. Zocor 80 mg should be used only in patients who have been taking this dose for 12 months or more without evidence of muscle injury, the FDA said.
The FDA also said health care professionals should switch such patients to another statin if they find that taking 40 mg of simvastatin isn’t meeting their LDL cholesterol goal, rather than raising the simvastatin dose to 80 mg.
The agency also revised the labels for simvastatin, Vytorin and Simcor to include new dosing recommendations when these drugs are used with certain medications, such as blood pressure medicines amlodipine and diltiazem, which interact to increase the level of simvastatin in the body, which can increase the risk for myopathy.
According to the FDA, 2.1 million patients were prescribed a simvastatin product that contained 80 mg of simvastatin last year. The majority of simvastatin patients are treated with 20 or 40 mg dosages.