Washington, Jan 25 : Researchers at University at Buffalo have warned that a popular arthritis drug Celebrex can produce cardiovascular side effects with arrhythmia, or irregular beating of the heart.
The study led by Indian scientist Satpal Singh revealed that Celebrex, which blocks pain by inhibiting an enzyme known as COX-2, diminished heart rates.
The research conducted over fruit flies and rats showed that low concentrations of the drug, corresponding to a standard prescription, reduced the heart rate and induced pronounced arrhythmia in the flies and the heart cells of rats.
The drug restrained the normal passage of potassium ions into and out of heart cells through pores in the cell membrane known as delayed rectifier potassium channels.
"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," he added.
The researchers are now examining the underlying molecular mechanisms responsible for the drug's action and its effect on other ion channels that play a prominent role in setting the rhythm of the heart.
"We are trying to determine whether the drug binds directly to the channels or to some other molecule, and if it acts by blocking the pore of the channel through which potassium ions travel or by some other mechanism," said Singh.
The results of the study appear in the Jan. 18 edition of the Journal of Biological Chemistry.