Celecoxib May Disrupt Heart Rhythm

Posted 1/25/08
Celecoxib (Celebrex), a popular arthritis drug that blocks pain by inhibiting an enzyme known as COX-2, has been shown in laboratory studies to induce irregular beating of the heart.

University at Buffalo researchers discovered this unexpected finding while conducting basic research on potassium channels, and their results were published in the January 18 edition of Journal of Biological Chemistry.

They found that drug amounts corresponding to a standard prescription reduced the heart rate and induced pronounced arrhythmia in fruit flies and the heart cells of rats. These effects were found to be due to a disruption in the movement of potassium ions between the cells.

“The adverse effects of drugs like Celebrex and Vioxx based on their selective inhibition of COX-2 currently are a topic of intense discussion in the medical community,” said Satpal Singh, PhD, of the University of Buffalo and senior author on the study. Vioxx was withdrawn from the market in September 2004.

“We now have shown an important new effect of Celebrex through a totally different pathway, one that is unrelated to the drug’s effect as a pain reducer,” Singh said. “The adverse effect arising from this unexpected mechanism definitely needs to be studied more closely, because the potassium channels inhibited by the drug are present in heart, brain and many other tissues in the human body.

“Because the main effect of the drug in our study was induction of arrhythmia, and arrhythmia is often the result of ion-channel dysfunction,” continued Singh, “we examined the drug’s effect on potassium channels and other ion channels in their models and were struck by the strong inhibition of the potassium channels.”

This article was adapted from a press release issued by the University of Buffalo.