New data fail to resolve the issue of COX-2 class effect.(News)

Despite widely reported results on the safety of Vioxx and now Celebrex and Bextra, there is still a paucity of information on the true long-term effects of these drugs as a class, and all of it will take months--if not years--to sort out.

The future of celecoxib (Celebrex) was uncertain at press time. Pfizer Inc., its maker, announced that an increased risk of heart problems had been found in one of two trials examining celecoxib for the prevention of colon cancer. The National Cancer Institute, which was conducting the study for Pfizer, suspended use of the drug after finding a 3.4 times greater risk of cardiovascular events in those taking 400 mg of celecoxib twice daily and a 2.5 times greater risk in those taking 200 mg of the drug twice daily, compared with placebo patients.

The average duration of treatment in the trial was 33 months.

Soon thereafter, research investigators suspended the Alzheimer's Disease Anti-Inflammatory Prevention Trial after preliminary data indicated a 50% increased risk for cardiovascular events in participants assigned to take 220 mg twice daily of the nonselective NSAID naproxen (Aleve, Naprosyn). Yet no significant increase in cardiovascular risk was seen in participants taking 200 mg twice daily of celecoxib.

In separate press releases, the Food and Drug Administration and the National Institutes of Health announced that only preliminary data had been reviewed.

The agencies are in the process of obtaining and reviewing all of the available data.

John M. Flack, M.D., director of the cardiovascular epidemiology and clinical applications program at Wayne State University, Detroit, said. "I don't think there's enough evidence at all to say this is a class effect, but I also don't think you can quite shut the door on it yet."