FDA Issues New Safety Label Requirements for Simvastatin-Containing Drugs
The US Food and Drug Administration announced yesterday that the cholesterol-lowering medication simvastatin would be required to have new safety label warnings because the highest approved dose (80 mg) has been associated with an elevated risk of muscle injury or myopathy. Simvastatin is sold in the US under the brand name Zocor and in the combination drugs Vytorin and Simcor.
Simvastatin is used together with diet and exercise to reduce the amount of low-density lipoprotein cholesterol (LDL or “bad” cholesterol) in the blood. High levels of LDL are linked to a greater risk of heart attack, stroke, and cardiovascular death.
The FDA recommends that the 80mg simvastatin no longer be prescribed for new patients but only used for those patients who have been taking this dosage for 12 months or more and who have not shown signs of muscle toxicity. If the lower 40 mg dosage does not adequately lower LDL, physicians should add another cholesterol-reducing drug rather than prescribe the higher dose.
Simvastatin was first approved by the FDA in 1991 under the brand name Zocor (Merck). The 80 mg dose was approved in 1998 with a generic form becoming available in 2006. Simvastatin is the second-most prescribed drug in the US. Over 2 million patients were prescribed simvastatin in 2010 and 12% of those were for the 80 mg dose.
The addition of stronger label warnings comes after a review of the seven-year Study of the Effectiveness of Additional Reductions in Cholesterol and Homocysteine (SEARCH) clinical trial, other trial data, and analyses of adverse events reported to the FDA. Patients taking 80 mg of simvastatin daily had a higher risk of muscle injury compared to patients taking lower doses or other statin drugs. The risk is highest during the first year of treatment and is often the result of interactions with other medications. It is also frequently associated with a genetic predisposition for simvastatin-related muscle injury.
Among the drugs that should be adjusted to avoid drug-drug interactions with simvastatin are gemfibrozil, cyclosporine, danazol, amiodarone, verapamil, and diltiazem. Posaconazole (Noxafil) should not be used with any dose of simvastatin.
In a press statement Merck said they have updated the US prescribing information. The company has also launched a website, www.simvastatininfocenter.com, to inform patients about the changes.