Side Effects of Cholesterol Drugs May Reduce Energy Levels: Study

The findings of new research suggest that individuals taking statins to lower their cholesterol may suffer side effects that increase fatigue. 

In a study published in the Archives of Internal Medicine, researchers from the University of California indicate that people who took cholesterol drugs that are part of a class of medications known as statins, which include Zocor, Crestor, Lipitor and other popular drugs, reported having less energy than those given a placebo.

The fatigue while using the cholesterol drugs was particularly found among women, and the highest reports involving low energy were seen among tose taking the blockbuster medication Zocor, or its generic equivalent simvastatin.

The study looked at 1,016 people ages 20 and older with elevated low-density lipoprotein (LDL) cholesterol, but who did not show signs of heart disease or diabetes. Four out of 10 women given Zocor said they felt more fatigue after exercising and had less energy in general than they did before taking the drug. Approximately 10% said the energy levels were “much worse.”

Less pronounced, but still statistically significant effects were also reported by users of Pravachol. Overall 21% of respondents complained of low energy or exertional fatigue when being given Zocor or Pravachol, compared to 6% who were on a placebo.

Statins are among the best-selling drugs in the United States, with $14.5 billion in combined sales in 2008. They use the liver to block the body’s creation of cholesterol, which is a key contributor to coronary artery disease. Statin is used in a number of other popular cholesterol controlling drugs, including Crestor, Lipitor, Mevacor and Lescol.

Zocor (simvastatin) is a synthetic statin developed by Merck & Co., which is widely available as generic simvastatin. Before patent protections expired in 2005, it was Merck’s best-selling drug and the second best selling cholesterol lowering drug in the world, bringing in $4.3 billion in 2005.

Side effects of statins have previously been linked to an increased risk of a muscle injury, known as myopathy. In severe cases, individuals may be diagnosed with a form known as rhabdomyolysis, in which the muscle fibers begin to break down, releasing a protein called myoglobin, which can damage the kidneys as they attempt to filter it out of the blood stream.

In June 2011, the FDA placed restrictions on the use of 80 mg Zocor, which could include twice-a-day 40mg doses, due to the risk of myopathy and rhabdomyolysis, warning doctors that no new patients should be placed on the high dose regimen due to the risk of muscle problems.

As a result of Merck’s failure to warn about the risk of rhabdomyolysis from Zocor 80mg doses, the drug maker faces a number of lawsuits brought by individuals who have been diagnosed with the condition.