In September 2004 Viox was withdrawn from the market. Viox was found to interfere with the heart. The debate of selective COX-2 inhibition drugs, like Viox and Celebrex continues in the medical community because of their potential for adverse side effects.

Satpal Singh, PH.D., associate professor of pharmacology and toxicology, University of Buffalo School of Medicine and Biomedical Sciences, was conducting basic research on potassium channels. What surprised Singh was how the normal prescription level of the arthritis drug, Celebrex, inhibits the normal passage of potassium ions into and out of heart cells, which can create an irregular heart beat–or arrhythmia.

Singh, and his research team, 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. The result is that Celebrex can have adverse side effects through an unexpected mechanism and result in an irregular heart beat.

The study appears in the January 18 edition of Journal of Biological Chemistry.