Cholesterol Drug May Harm Kidneys

High cholesterol patients taking fibrates may risk kidney damage

(RxWiki News) On top of diet and exercise, medications can help you control your cholesterol. Be careful, though. Some of these medications may pose a threat to your health.

Fibrates, a common type of cholesterol drug, may be harmful to your kidney health.

"Ask your doctor about side effects of your cholesterol drugs."

Fibrates are a class of drugs frequently used to treat high cholesterol. Recent studies have shown that fibrates can cause a rise in levels of serum creatinine, a sign of kidney damage.

When Amit Garg, M.D., Ph.D., of Lawson Health Research Institute, and colleagues noticed some of their patients taking fibrates were experiencing kidney problems, they decided to study the issue further.

They found that new fibrate users were more likely to be hospitalized for a rise in serum creatinine levels, compared to patients taking ezetimibe (sold as Zetia) - another cholesterol drug that is not known to impact the kidneys.

Their results also show that fibrate users are more likely than ezetimibe users to visit a kidney specialist.

For their study, Dr. Garg and colleagues looked at nearly 20,000 fibrate users and more than 60,000 ezetimibe users over the age of 65. All of the participants had received their prescription within the past 90 days.

While there was no difference between the groups for risk of receiving dialysis for severe acute kidney injury, fibrate users had a larger increase in serum creatinine levels.

Slightly more than 9 percent of fibrate users had at least a 50 percent increase in serum creatinine levels. In comparison, 0.3 percent of ezetimibe users had an increase in serum creatinine levels of at least 50 percent.

According to the authors, it is still unclear exactly how fibrates impact kidney function. More research is needed to understand the mechanisms by which fibrates may harm the kidneys.

This study shows that fibrates have a larger impact on kidney function and the measurement of kidney function than was previously known.

"At the end of the day, we want to prescribe medication with the highest benefit and the least amount of adverse events," says Dr. Garg.

"When a physician decides to start a fibrate in a new patient, especially an older patient, given the information we have today they should start the patient on a dose that's appropriate, closely monitor their kidney function, and, if the kidney function goes off, either lower the dose or discontinue the drug," Dr. Garg explains.

One limitation of this population-based study was that serum creatinine levels were measured as part of routine care. This means that the researchers could not measure serum creatinine levels at the same time for each patient. It also means that levels were not available for every participant.

The study was funded by the Ontario Ministry of health and Long-Term Care Drug Innovation Initiative.

The results are published in the Annals of Internal Medicine.

Review Date: 
April 17, 2012