The muscle injury risk was found particularly high in patients....

On March 19, the Food and Drug Administration notified health care professionals as well as patients that data from a large clinical trial and other sources indicated that use of Zocor, a statin made by Merck and commonly used to lower cholesterol by consumers to lower cholesterol, raises risk of muscle injury when used in large doses and in some patients on other medications.

The muscle injury risk was found particularly high in patients who took the highest approved dose of 80 milligrams per day of the cholesterol-lowering medication, Zocor which is based on simvastatin, an active ingredient that is also used in other products.

In the Drug Safety Communication titled Ongoing Safety Review of High-dose Zocor (simvastatin and Increased Risk of Muscle Injury, the FDA says the risk of muscle injury in patients taking the highest approved dose of the cholesterol-lowering medication, Zocor was higher than that in patients taking lower doses of Zocor and possibly other statins.

The muscle injury of concern is also called myopathy. It is actually a side effect with all statin medications, according to the FDA. The common symptoms include muscle pain, tenderness or weakness, elevated level of a muscle enzyme in the blood called creatine kinase. High doses of Zocor lead to high risk of muscle injury. The risk is elevated particularly when Zocor is used together with certain other drugs.

For the safety reason, the FDA suggests patients should not use Zocor if they use itraconazole, ketoconazole, erythromycin, clarithromycin,telithromycin, HIV protease inhibitors, and nefazodone. Patients on diltiazem may use no more than 40 milligrams of Zocor per day. Those on Amiodarone and verapamil may use no more than 20 milligrams of Zocor per day. Those on Gemfibrozil, cyclosporine and danazol may use no more than 10 milligrams of Zocor per day.

The most serious form of muscle injury is rhabdomyolysis which occurs when a protein called myoglobin is released as muscle fibers break down. This protein can damage the kidneys as they filter blood out of the body. Symptoms of this condition include dark or red urine and fatigue in addition to other common muscle injury symptoms. In rare cases, rhabdomyolysis can lead to fatal kidney failure.

The FDA says healthcare professionals should know that rhabdomyolysis is rare, but reported with all statins and they should be aware of the potential risk of muscle injury from the 80 milligrams of Zocor per day.

The drug regulator advises that patients should not stop taking Zocor unless told so by their healthcare professionals. In cases patients experience symptoms of muscle injury including muscle pain, tenderness or weakness, dark red urine or unexplained tiredness, they should contact their healthcare professionals.

The SEARCH trial of 6031 patients who had experienced a heart attack prompted the FDA to issue the warning. The trial results showed that among those who took 80 milligrams a day of Zocor, 0.9 percent experienced muscle injury compared to 0.02 percent among those who took only 20 milligrams of Zocor per day. Eleven patients who used 80 milligrams of Zocor per day developed rhabdomyolysis compared to none among those who used only 20 milligrams.

The risk is not news. In 2008, the FDA alerted the public to an increased risk of rhabdomyolysis in patients using higher than 20 milligrams of simvastatin in the drug called amiodarone.

One ongoing trial called the Heart Protection Study 2 resulted in some interim outcomes suggesting that patients of Chinese descent should not use 80 milligrams of simvastatin with cholesterol modifying doses of niacin-containing products.

Accordingly, in March 2010, the health agency approved a labeling revision for simvastatin. The revised label also recommends that patients receiving cholesterol-modifying products should take no more than 40 milligrams of Zocor per day.

The ongoing trial found 0.43 percent of patients of Chinese descent suffered myopathy compared to 0.03 percent of their counterparts not taking 40 milligrams plus cholesterol modifying products.

Statins are a class of cholesterol-lowering medications, which are controversial because studies have found these drugs are not worth the money or at least not effective as desired in preventing heart disease. In some cases they do more harm than good.

Statins may disappoint some patients. Luckily some modified lifestyle including healthy diet can lower cholesterol, most importantly risk of heart disease. Those who are interested should contact Dr. Dean Ornish, a Harvard educated medical doctor who is a professor at the University of California - San Francisco.

Some doctors say medical research has provided evidence suggesting that cholesterol is not the cause for the risk of heart disease. In addition to muscle injury, taking Zocor and other statins may also raise risk of diabetes, heart failure and eye disorder, as reported early on foodconsumer.org.

In any event, following a healthy diet is the fundamental way to reduce the risk of heart disease. Dr. Ornish uses his diet and lifestyle program based on a modified diet to help patients prevent progression of artery clogging and reverse atherosclerosis. The efficacy is said to be 99 percent, according to Dr. Colin T Campbell, a distinguished Cornell University nutrition professor.