Merck’s popular cholesterol lowering drug Vytorin has recently been linked to a number of severe side effects including muscle damage, myopathy, rhabdomyolysis and kidney failure. Doctors and patients are being advised to weigh the risks vs. benefits of taking Vytorin carefully before beginning a regimen.
Vytorin Update 3/1/12: The U.S. Food & Drug Administration (FDA) issued a press release today informing healthcare professionals of updates to the prescribing information concerning adverse interactions between protease inhibitors and certain statin medications. When these two types of drugs are taken together, they may raise the blood levels of statins and increase the risk of a severe muscle injury known as myopathy.
Vytorin Update 2/28/12: The U.S. Food & Drug Administration (FDA) issued a press release today stating that it will be requiring all statin drugs to carry a new warning about the increased risk of elevated blood sugar and possible transient memory and cognition problems. The label changes will apply to atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), lovastatin extended-release (Altoprev), pitavastatin (Livalo), pravastatin (Pravachol), rosuvastatin (Crestor), and simvastatin (Zocor).
What’s the problem?
Approximately 20 percent of adult Americans have high cholesterol, which can lead to heart attacks and strokes, two of the leading causes of death in the United States. Taking these statistics into consideration, it’s easy to understand why the market for cholesterol-lowering medications such as Vytorin is so large.
Vytorin is an FDA-approved drug that combines ezetimibe and simvastatin to treat high cholesterol in adults and children over the age of 10. Ezetimibe reduces the amount of cholesterol absorbed by the body, and simvastatin reduces levels of ‘bad’ cholesterol (low-density lipoprotein, or LDL) in the blood while increasing levels of ‘good’ cholesterol (high-density lipoprotein, or HDL). Vytorin was approved by the U.S. Food & Drug Administration in 2004, and is a registered trademark of MSP Singapore Company, LLC, a subsidiary of Merck & Co.
In addition to Vytorin, other potentially-dangerous medications from the statin class include:
Side Effects of Vytorin
Despite its relative effectiveness at treating high cholesterol, high doses of Vytorin have recently been linked to the following potentially life-threatening side effects:
- muscle damage
- kidney damage
- kidney failure
Vytorin has been shown to increase the risk of myopathy, a severe form of muscle damage characterized by muscle fibers no longer being able to function correctly. Signs and symptoms vary significantly depending the severity of the disorder, but generally include:
Treatment for Vytorin-induced myopathy depends on the condition of the disease. Options may include drug therapy (treatment with immunosuppressives), physical therapy, bracing to support weakened muscles, or surgery. For severe cases of myopathy, supportive or symptomatic treatment may be the only beneficial course of action for treatment.
“The FDA has completed its review of the safety of high-dose simvastatin and is making label changes to reduce the risk of statin-associated muscle injury,” said Eric Colman, M.D., deputy director of the Division of Metabolism and Endocrinology Products in the FDA’s Center for Drug Evaluation and Research. “We want to ensure that patients and health care professionals are aware of the new labeling changes to simvastatin, including the increased risk of myopathy when using the 80 mg dose of simvastatin.”
Rhabdomyolysis is a rare but serious form of myopathy characterized by the rapid breakdown of skeletal muscles, which results in the release of muscle fiber contents (myoglobin) into the bloodstream. This is toxic to the kidneys, and often results in severe kidney damage and even complete kidney failure. Symptoms of rhabdomyolysis may include (but are not limited to):
- muscle pain
- tenderness, weakness or swelling of the affected muscles
- low blood pressure
- abnormal heart rate and rhythm
Vytorin Zocor ENHANCE Study
It was believed that the treatment of cholesterol from both ezetimibe and simvastatin would likely result in lower cholesterol levels. It was also thought that this reduction in cholesterol would reduce the amount of plaque buildup in the arteries, thus reducing the risk of heart attack and stroke. However, the results of the 2008 ENHANCE study revealed that taking Vytorin had no benefit on the buildup of artery plaque when compared to patients taking simvastatin, the generic version of Zocor. The study, which was funded by Merck and Schering-Plough, failed to meet its primary goal, which was to show whether Vytorin was more effective than Zocor alone in preventing atherosclerosis in the carotid artery.
The study’s findings are important because Vytorin costs three times more than simvastatin. Merck has disputed the research, but within a month a class action lawsuit was filed against the company claiming that Zocor was no more effective than its cheaper generic, despite leading consumers to believe the opposite.
There has been considerable speculation that Merck and Schering-Plough tried to cover up the results of the ENHANCE study. The trial’s research was supposed to be released in March 2007, but it never happened. Later that year, a doctor who supervised the trial came forward to the New York Times and said that the manufacturers had blocked the study’s release. According to the doctor’s statement, both companies had attempted to change the study’s endpoint, the generally accepted medical result that must never be changed for a clinical trial to be valid.
It is easy to understand why Merck and Schering-Plough would have wanted to hold back the results of the ENHANCE study. Vytorin sales make the companies billions each year, and the study’s findings put those sales at serious risk, as many doctors may opt to prescribe simvastatin (roughly $1 per pill) rather than Vytorin (about $3 per tablet).