MONDAY, Dec. 6, 2004 (HealthDayNews) -- A new study finds that Celebrex, the first in a family of stomach-friendly painkillers called cox-2 inhibitors, is safer for the heart than Vioxx, a similar drug that has been linked to cardiovascular problems.
Cox-2 inhibitors, or coxibs, have come under fire since September, when Merck & Co. pulled Vioxx from the market after its researchers noted an increased heart attack risk in people taking the drug. Preliminary information shows that Bextra, another coxib, may have similar problems among patients with heart disease. Its maker, Pfizer Inc., has disputed that information, but has said it will add a strong warning on the package about a potentially fatal skin reaction.
These events have prompted a flurry of speculation as to whether all cox-2 inhibitors, which were developed as pain relievers that don't cause gastrointestinal problems, are dangerous. Even with these new results, another expert said the jury is still out on the issue.
For this latest study, researchers at the University of Pennsylvania School of Medicine reviewed records on 1,718 people who had been admitted to 36 hospitals with a nonfatal first heart attack, and compared them to 6,800 people who had not had a heart attack from the same geographical area.
People who had taken Vioxx had a 2.72 times higher chance of having a heart attack compared to people taking Celebrex.
People taking Vioxx also had a higher risk for heart attack than did patients taking nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, ibuprofen and naproxen.
"It appears that not all cox-2 inhibitors are the same with respect to
their effect on heart risk," said Stephen Kimmel, an associate professor of medicine and epidemiology at Penn. "We can't exclude a small increase in
risk from Celebrex. We just didn't see one here."
Just because his team didn't see an increase in risk from the drug, "that doesn't mean you should use Celebrex indiscriminately," Kimmel added.
The study was funded by grants from the U.S. National Institute of Health as well as Merck and Pfizer, which also makes Celebrex.
Another expert questioned the safety of the class as a whole.
"The big question at this point is whether the adverse effects are related to the sustained inhibition, which would be the same for all cox-2 inhibitors, or is it a drug-specific mechanism?" said Dr. Axel Finckh, a rheumatology researcher at Brigham and Women's Hospital in Boston. "At this point, I don't think we can really know."
Finckh co-authored an editorial accompanying the study, which appears in the Dec. 7 online issue of the Annals of Internal Medicine.
Finckh and his co-author, Dr. Mark D. Aronson, a general internist at Beth Israel Deaconess Medical Center in Boston, recommended that no coxibs be used as first-line treatments.
"There have been two drugs within the class of cox-2 inhibitors that have been associated with some worrisome data on excessive cardiac morbidity and, at this point, we cannot exclude that there is a cox-2 inhibitor class effect for cardiotoxicity," Finckh said. "We thought prudence would tell us to avoid these drugs in patients that have increased cardiovascular risk."
That category he said, includes people who smoke, who have a past history of cardiovascular events, and who are older than 65, among other things.
Finckh said it's important to note this new study was an observational one, and therefore not accorded the same weight as a randomized controlled trial. To understand fully what mechanisms are at play, this study needs to be backed up by others.
"I don't think we know enough right now to really point out one mechanism," Finckh said.
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