The mechanism of the life-threatening drug-interaction of Bayer’s cholesterol-lowering agent Lipobay/Baycol clarified

Researchers from Finland have found that the cholesterol-lowering agent gemfibrozil (marketed as Lopid and generics) greatly increases the concentrations of cerivastatin (Lipobay or Baycol) in blood. This finding explains the observed muscle toxicity of the gemfibrozil-cerivastatin combination. This potentially fatal adverse effect of cerivastatin led to the withdrawal of Lipobay/Baycol from the market.

The concentrations of Lipobay were increased on average 5-6-fold by Lopid, in some individuals even 10-fold, in a study in healthy subjects. The study was conducted in the Department of Clinical Pharmacology, University of Helsinki, by an independent group of researchers led by professor Pertti Neuvonen, MD, and Dr. Janne Backman, MD. This new finding is believed to explain a large number of the muscle toxicities and deaths reported in patients taking Lipobay.

The German pharmaceutical company Bayer withdrew Lipobay/Baycol from the market worldwide last year. At least 500 cases of muscle damage, including 100 deaths, have been reported in patients taking the drug. In almost half of the cases, Lipobay/Baycol had been used in combination with Lopid. The withdrawal of Lipobay/Baycol was a great disappointment and huge financial loss to the company that is best known as the inventor of aspirin.

Combinations of lipid-lowering agents are used for treatment of mixed-type lipid disorders. Muscle toxicity is a rare but potentially serious adverse effect of all statin-type cholesterol-lowering drugs like Lipobay. The risk of muscle toxicity during treatment with statins increases when their concentrations in blood increase too much.

Gemfibrozil has been found to increase moderately the concentrations and muscle toxicity of also some other statins, such as simvastatin (Zocor and generics). Yet, these statins can be cautiously coadministered with gemfibrozil without compromising patient safety.

The study was published in the December issue of the respected scientific journal Clinical Pharmacology & Therapeutics.