• Liver disease (history of disease or persistently high liver enzymes). Use of fenofibrate may lead to worsening liver problems. In addition, use of clofibrate or gemfibrozil in patients with existing liver disease may result in a buildup of this drug in the bloodstream, increasing the potential for side effects.

  • Kidney disease. This condition may lead to a buildup of fibrates in the bloodstream, increasing the potential for side effects and (in the case of fenofibrate) increasing the risk of worsening existing kidney problems.

  • Gallbladder disease or gallstones. Fibrate use may lead to a worsening of these conditions.

  • Ulcers of the stomach or intestines. Use of clofibrate may lead to a worsening of ulcers.

  • Hypothyroidism (underactive thyroid gland). Use of clofibrate may complicate treatment of this condition.

  • Increased homocysteine levels. Use of fenofibrate may raise the blood level of homocysteine, an amino acid produced as a normal byproduct of the breakdown of methionine, which is an essential (dietary) amino acid acquired mostly from eating meat and protein. High homocysteine levels have been linked to artery damage, which may increase the risk of heart attack, stroke or other cardiovascular problems. Research is ongoing to determine whether high homocysteine levels are an actual cause of those conditions, or are simply associated with them for some other reason. However, some physicians recommend patients taking fenofibrate also take folic acid, which lowers homocysteine levels.

  • Heart transplant. Use of fibrates has been shown to affect the levels of cyclosporine, which could possibly lead to transplant rejection.