The FDA's arthritis and drug safety advisory committees, concluding three days of meetings to assess the risks of three popular painkillers called Cox-2 inhibitors, were to address Vioxx and Bextra later in the day.
The advisers also were set to frame recommendations to the FDA about whether further testing is needed for the drugs and any special warnings or limits that should be placed on them.
The committees were asked to assess the drugs after Vioxx was pulled from the market last fall because of heart problems in users. Since then questions have been raised about the Bextra and Celebrex as well.
Committee members noted that Celebrex seems to have the least heart side effect of the three drugs, though some complained about the lack of needed data.
CBS News Correspondent Barry Bagnato reports the committees are now discussing limits on its use and warnings that should be provided about cardiovascular risks.
Meeting chairman Alistair J.J. Wood of Vanderbilt University Medical School said the safety problems reported in connection with Cox-2 inhibitors exceed those of products that have been withdrawn from the market.
However, since the side effect involving heart attacks, irregular heartbeat and stroke is a relatively common problem, that makes it harder to pin it to the drugs than if it were a rare side effect.
Dr. Peter S. Kim, president of Merck Research Laboratories, had told the joint meeting of two FDA committees earlier that new studies indicated the side effects aren't unique to its product.
All three drugs have been approved for sale by the government. The committees' recommendations could be the first steps toward rescinding those approvals or taking other actions ranging from tougher label warnings to extensive new safety studies of the drugs.
Dr. Robert Temple, director of medical policy for the FDA's Center for Drug Evaluation and Research, told the committees on Friday that "the idea of doing a large new study has weight."
"There are some data we'd all like to have, that we don't have," Temple said, including the blood pressure and other effects of the various drugs.
He said a new study might include more than just the Cox-2 drugs, possibly adding such widely used painkillers as ibuprofen, naproxen and diclofenac.
"My main point is that there is a very important need for more information on many of these drugs," Temple said.
On Thursday, Wood asked whether the drugs could win approval today, considering the studies that have come to light in recent months.