WEDNESDAY, Feb. 23, 2005 (HealthDay News) -- A ray of hope may be emerging for the makers of cox-2 inhibitors, the class of drugs under such intense scrutiny at last week's government hearings.
A new study finds the cox-2 drug Celebrex may be safe and effective to use on a short-term basis in patients with stable cirrhosis of the liver.
The news comes less than a week after a U.S. Food and Drug Administration advisory panel recommended the cox-2 drugs stay on the market -- but with the addition of a black-box label warning of potential cardiovascular risks.
"This study provides an important, potential niche usage for selective cox-2 inhibitors in people with chronic liver diseases, based on their better safety profile in very short term use versus non-selective NSAIDs," said Dr. Scott Friedman, chief of the division of liver disease at Mount Sinai School of Medicine in New York City.
Friedman was not involved with the study, which appears in the March issue of the journal Hepatology.
Forbes magazine reported this week that Celebrex's manufacturer, Pfizer, Inc., is planning a study to compare Celebrex's safety profile with another anti-inflammatory pill. According to the magazine, that other pill is likely to be naproxen (Aleve) -- the same drug Celebrex is pitted against in the cirrhosis study.
These moves may signal a change in Pfizer's handling of Celebrex, as the company moves away from previous trials that attempted to prove the drug's superiority to other products in protecting the heart. Instead, according to the Forbes article, it now appears the company may be satisfied with trials aimed at proving Celebrex simply poses no greater cardiovascular risk than its rivals.
Members of the FDA advisory panel did indicate that the black box could be removed from Celebrex labeling if future trials showed a favorable safety profile.
This latest study in Hepatology focuses on a whole new safety issue, however: kidney problems.
The drugs known as nonsteroidal anti-inflammatories have long been associated with kidney failure in patients with cirrhosis of the liver. But there's been some evidence indicating that cox-2 inhibitors -- a subclass within the category of NSAIDs -- may be exempt from this problem.
In their study, the researchers from Barcelona's Hospital Clinic compared Celebrex with the traditional NSAID naproxen and a placebo in 28 patients with cirrhosis of the liver. Cirrhosis, which is often linked to excessive drinking, occurs when scar tissue impedes normal liver function.
All the study participants were randomly assigned to receive five doses of Celebrex, naproxen or placebo over a period of five days. The final analysis was based on data from 18 individuals.
Based on this short-term data, Celebrex turned out to be safer than naproxen, having no effect on kidney function.
Regardless, experts still advise caution.
"Most physicians and patients also recognize that these drugs, whether they're selective or non-selective, should only be given when absolutely indicated," Friedman said.
The long-term effects of the drugs are still an open question and the study authors did acknowledge the need for more research in this area.
"They did not assess long-term safety, but if there was a clear indication for a cox-2 for short-term use -- for example, patients who had musculoskeletal or orthopedic issues that required short-term treatment -- the data would suggest that a cox-2 would be safer than a traditional NSAID," Friedman said.
Also, all of the patients in the study had very stable disease, he added. "It would not be appropriate to extrapolate this to the use of cox-2 selective antagonists in patients with more advanced liver disease," Friedman said. "These patients had stable cirrhosis and were otherwise healthy."
The data, Friedman added, is not really all that surprising since prior animal studies had indicated that the kidney problems associated with NSAIDs were attributable to the blockage of the cox-1 enzyme rather than the cox-2 enzyme.
Traditional NSAIDs such as naproxen block both enzymes, while the cox-2 inhibitors, as their name suggests, block only the cox-2 variant.
More information
The National Institutes of Health has more on cirrhosis of the liver.
