The safety of Celebrex and other pain relievers was questioned Wednesday as scientists in the United States and regulatory agencies in Europe said they feared such drugs might raise the same risk of heart problems as those blamed on the arthritis medicine Vioxx.

One key researcher charged the U.S. Food and Drug Administration did not do everything needed to make sure the drug was safe and called for a congressional review of how Vioxx was approved.

Heavily advertised as an arthritis drug, Vioxx was pulled from the market last week after its maker said a study showed it doubled the risk of heart attack and stroke. But the FDA said similar prescription drugs were safe.

The European Medicines Agency in London announced it would review all drugs of this type. And researchers writing in the New England Journal of Medicine voiced their concerns as well with such drugs as Pfizer’s popular Celebrex and its newer drug, Bextra.

The medical journal published two reports on the issue Wednesday on the Internet — more than two weeks ahead of their planned print publication — to help inform doctors and patients considering whether to stop using the drugs.

Studies done five years ago when Celebrex and Merck & Co.’s Vioxx were approved suggest that the same mechanism that inhibits inflammation and makes the drugs easier on the stomach than traditional painkillers also blocks a substance that prevents heart problems, according to Dr. Garret FitzGerald, a University of Pennsylvania cardiologist. FitzGerald led the studies, which were designed by him but funded by the drug companies.

“I believe this is a class effect,” he said, meaning that the problem also applies to Celebrex and Bextra, which remain on the market.

Pfizer’s medical director, Dr. Gail Cawkwell, insisted that its drugs were safe.

“The data for Celebrex is robust and exceeds, in the length of patients in studies and in the size of studies, the data Vioxx has,” she said.

Scientists are questioning whether Celebrex, left, and other pain drugs cause the same heart problems that last week forced Merck to pull its Vioxx arthritis medicine, right, from the market.

She called FitzGerald’s contention “an interesting theory,” but said, “there is no evidence” of increased risk of heart problems among the 75 million Americans who have taken Celebrex. Long-term studies are not yet available on Bextra, which was approved in 2001.

Celebrex is the 10th most popular drug in the United States, with annual sales of $2.7 billion, up 5 percent in a year, according to IMS Health, a company that tracks drug industry trends.

In a separate report also released by the medical journal, Dr. Eric Topol of the Cleveland Clinic chastised the FDA for not requiring Merck to do studies investigating heart problems with Vioxx when hints of them first appeared years ago, and for allowing the company to blitz consumers with TV ads touting the drug.

Vioxx was the largest prescription drug withdrawal in history, “but had the many warning signs along the way been heeded, such a debacle could have been prevented,” Topol wrote. “Neither Merck nor the FDA fulfilled its responsibilities to the public. … I believe there should be a full Congressional review of this case.”

An FDA official said the agency would have no immediate comment.

When Merck voluntarily withdrew Vioxx, FDA officials said heart problems were unique to that drug and that the mechanism underlying them wasn’t known.