Zocor and Rhabdomyolysis

The cholesterol-lowering medication Zocor (simvastatin) has been associated with a severe, life-threatening side effect called rhabdomyolysis — a severe degenerative muscle disease (myopathy) that can cause kidney failure or death. The FDA has warned that this risk is especially high when 80-mg Zocor is used for at least a year, or when Zocor is combined with certain other medications (such as amidarone).

What is Zocor?

Zocor (simvastatin) is a type of drug called a statin, which is prescribed to lower cholesterol. Zocor works by blocking a critical enzyme, which reduces the amount of Low-Density Lipoprotein (LDL) cholesterol (or “bad cholesterol”) that circulates in the bloodstream. This reduces a patient’s risk of suffering a severe cardiovascular event, such as heart attack or stroke.

Zocor was created by the drug company Merck & Co. It was approved by the FDA in 1991 and is now available as a generic.

Zocor and Rhabdomyolysis

The FDA has published several warnings about the risk of rhabdomyolysis — one of the most severe side effects of Zocor, especially when Zocor is taken at high doses (80-mg) or low-dose Zocor is combined with certain other drugs.

Rhabdomyolysis is a degenerative muscle disease. It occurs when muscle fibers break down and release myoglobin, a protein inside muscle fibers. Myoglobin is filtered out of the bloodstream by the kidneys. Unfortunately, the kidneys’ filtering tissue can become clogged with myoglobin, causing kidney damage, kidney failure, or even death.

According to the FDA, rhabdomyolysis is a rare side effect of statins, but the risk is higher for Zocor than most other statins. Hospitalization for rhabdomyolysis occurs in about 5 people per 100,000 who take Zocor.

Symptoms of Rhabdomyolysis

Rhabdomyolysis associated with Zocor may have the following symptoms:

• Muscle pain or tenderness
• Muscle weakness, especially in the arms or legs
• Muscle crams, spasms, or stiffness
• Elevated levels of muscle enzymes in the blood
• Confusion
• Fever
• Dark urine or decreased urine output

FDA Warnings for Zocor Rhabdomyolysis

After receiving dozens of adverse event reports, the FDA has published multiple safety communications to warn about the risks of high-dose Zocor and the risk of combining Zocor with certain other medications.

• June 2011 Safety Communication — The FDA recommends limiting the use of 80-mg Zocor due to the risk of rhabdomyolysis. They advise doctors against prescribing 80-mg Zocor to new patients due to this side effect.
• December 2011 Safety Communication — The FDA advises against combining amiodarone plus Zocor in a dose higher than 20-mg due to the risk of rhabdomyolysis.
• March 2012 Safety Communication — The FDA warns about the increased risk of rhabdomyolysis when Zocor is combined with an anti-viral protease inhibitor medication, which are commonly used to treat HIV and hepatitis C.

Zocor Class Action Lawsuit

Many people have already filed lawsuits against Merck for rhabdomyolysis and other injuries associated with Zocor. A Zocor class action lawsuit has been filed in the U.S. District Court for the Eastern District of Louisiana. The lawsuit states, in part:

“The pharmaceutical drug, Zocor, is defective, dangerous to human health, unfit and unsuitable for be marketed and sold in commerce, and lacked proper warnings to the dangers associated with its use.”

Individual lawsuits have also been filed in federal court. Most plaintiffs allege that Merck failed to adequately warn doctors and the public about the risk of muscle disease associated with Zocor. Plaintiffs are now seeking justice for their injuries.