PHILADELPHIA -- New research suggests that top-selling pain reliever Celebrex does not carry the same heart attack risk as Vioxx, a similar drug pulled from the market in September because of safety concerns.
The study, by researchers at the University of Pennsylvania, is the first to compare the two arthritis drugs since the recall, and contradicts claims by other scientists that all so-called cox-2 inhibitors may carry similar dangers.
"Vioxx and Celebrex look different. Relative to Celebrex, Vioxx had about a threefold greater risk of heart attacks," said Dr. Stephen Kimmel, lead author of the study.
"What that implies is that all cox-2 inhibitors may not be the same."
The study, funded by the makers of both drugs and the federal government, was published in the Annals of Internal Medicine. Researchers surveyed 1,718 patients in the Philadelphia area who had heart attacks, and a comparison group of 6,800 people.
The chances of having a heart attack were 2.72 times greater in Vioxx users than in Celebrex users, the researchers said.
But they also found that patients using either drug were not at a significantly greater risk of having a heart attack than those who did not use either drug.
In fact, Celebrex users had a lower risk of a heart attack than people who didn't take either drug, though the researchers said that finding could have happened by chance.
In an accompanying editorial, two Boston doctors warned that the connection between heart disease and cox-2 inhibitors remains unclear.
As a result, they recommended that doctors avoid prescribing any drug in that class to patients already in danger of heart disease, unless they run a significant risk of gastrointestinal problems.
Cox-2 inhibitors are believed to be easier on the stomach than other pain relievers.
"We don't think that we really understand what is triggering the increased risk of heart problems in some patients," said Dr. Axel Finckh, rheumatology researcher at Brigham and Women's Hospital. "We cannot exclude the possibility that there is a cox-2 class effect."