Merck Redesigns Drug Label for Zocor, Propecia, Januvia, Other Drugs

Federal regulators have signed off on a redesign for the labels of a number of Merck drugs, including Zocor, Propecia, Januvia and a dozen other drugs, to improve readability and reduce the risk of medication mistakes and prescription errors.

The FDA announced its approval for a new standardized format last week, after Merck proposed a revisions to the container labels for 16 solid oral drug products. The new labels are designed to provide better information to help differentiate the products and strengths of the various drugs.

The new label designs will affect the following Merck drugs: Cozaar, Crixivan, Hyzaar, Isentress, Janumet, Januvia, Mevacor, Noroxin, Prinivil, Prinizide, Propecia, Proscar, Singulair, Zocor, and Zolinza. The labels were designed using a scientific approach and then had to be approved by eight different divisions of the FDA’s Center for Drug Evaluation and Research (CDER).

The FDA has asked health care providers to report any medication errors involving the new labels so that the agency can properly grade and monitor their effectiveness. Merck label medication errors should be reported to the FDA’s MedWatch adverse event reporting program.

The new label design standardization was approved at the end of a week in which the FDA announced new warnings about potential health problems with several of the Merck drugs included in the project, including Zocor, Propecia and Proscar.  However, there is no indication that the timing of the announcements were related.

On June 8, the FDA recommended that no new patients be started on an 80 mg Zocor (simvastatin) regimen, due to the risk of myopathy, rhabdomyolysis, kidney damage and other muscle injury. Zocor is one of Merck’s best-selling medications, which is also widely avaiable as generic simvastatin.

Rhabdomyolysis from Zocor causes muscle fibers to begin to break down, releasing a protein called myoglobin, which can damage the kidneys as they attempt to filter it out of the bloodstream. Symptoms of rhabdomyolysis include muscle cramps, tenderness, stiffness, pain or spasms. The illness is usually reported in patients over 65 years of age or those who have renal impairment or uncontrolled hypothyroidism. 

On June 9, the FDA issued a drug safety alert for Propecia, Proscar and similar drugs, warning that the hair loss and enlarged prostate treatment drugs could increase the risk of the more serious forms of prostate cancer.

Propecia (finasteride) was approved in 1992 for the treatment of benign prostatic hyperplasia, and also is approved to treat male pattern baldness. It was originally marketed by Merck as Proscar.

In addition to cancer concerns, researchers from the U.S. published a study in the Journal of Sexual Medicine in March that found side effects of Propecia and similar drugs were linked to sexual problems in men. Researchers indicated that 5-alpha-reductase inhibitors can cause loss of libido, depression erectile dysfunction, reduced semen production and growth of male breast tissue. They also agreed that in some cases these side effects appeared to be permanent.