FDA Takes Tougher Stand on Zocor 20 Years After Initial Approval

Washington, DCThe announcement earlier this month by the US Food and Drug Administration (FDA) with regard to serious Zocor side effects has prompted critics to wonder what cumulative damage the 80mg dose of Zocor (simvastatin) has wreaked in the 20 years since its approval by he FDA in 1991.

That's the point made by blogger Matthew Herper, writing in the June 9 issue of Forbes. According to Herper, quoting FDA statistics, 2.1 million Americans were prescribed the 80-milligram dose of Zocor last year—either on its own or in combination via a hybrid product such as Simcor or Vytorin.

There is little doubt that statins remain effective in helping patients control problematic cholesterol—a fact echoed by noted cardiologist Steven Nissen of the renowned Cleveland Clinic. Statins, he said, are "among the safest and most important drugs in all of medicine."

At the same time, however, Nissen has been railing since 2004 that patients should not be using the 80mg Zocor due to Zocor side effects.

Among those adverse reactions are Zocor liver damage and Zocor muscle damage, known as myopathy.

While the FDA has taken a more profound stance on Zocor 80mg by issuing the decree that no new patients should start on Zocor or Vytorin 80mg—and that only existing patients who have taken the drugs for longer than 12 months without developing muscle pain should remain with it—the FDA has been advancing cautions about Zocor simvastatin since 2002. It took the health regulator nine years to issue a more rigid warning.

The health stakes are high. Herper references script data from IMS Health suggesting that 80mg doses of simvastatin (Zocor or generics) were prescribed 11.3 million times last year. For Vytorin (a hybrid drug that contains simvastatin), the volume was 1 million.

It is not known why the FDA's more rigid cautionary tone has emerged 20 years after Zocor first appeared on the market or why a Zocor study was not undertaken sooner. Various studies have been done on the Zocor drug, including a large trial by simvastatin manufacturer Merck and Co. known as the Zocor SEARCH study. The results of that study prompted the FDA to probe deeper into the Zocor/simvastatin portfolio.

Herper believes it was relatively easy for the FDA to take the tougher stance on 80mg Zocor because there are a host of other options that offer increased potency with limited risk. However, one wonders as to the fate of patients who have been taking 80mg Zocor or Vytorin for all this time.

According to IMS, a whopping 253 million prescriptions for cholesterol drugs were written in the US last year alone. Zocor is just one of them.