U.S. government health officials convened a public hearing Friday on whether to ban Darvon, a painkiller first approved in 1957, when there were few alternatives for treating pain except aspirin and powerful narcotics.

Now mainly marketed as Darvocet, which includes a dose of acetaminophen, the drug remains one of the top 25 most commonly prescribed medications in the U.S. More than 20 million prescriptions were written in 2007.

The consumer group Public Citizen said the Food and Drug Administration should withdraw Darvon from the market because the drug offers relatively weak pain relief and poses an overdose risk, with the potential to be used in suicides.

"It has unique risks and no unique advantages," said Dr. Sidney Wolfe, a drug safety expert with Public Citizen who first sought a ban in the 1970s. "It has been a big drug of abuse for quite a long time."

Two companies that market the drug — Xanodyne Pharmaceuticals and Qualitest/Vintage Pharmaceuticals— say the medication is safe and effective when used as directed. In documents filed with the FDA, the companies say doctors need a range of options to treat pain, and note that many other painkillers have become drugs of abuse.

Dr. Jerry Avorn, a professor of medicine at Harvard and a critic of the pharmaceutical industry, is glad the FDA is taking a hard look at Darvon.

"I have been astonished at how widely used this drug is," Avorn said. "It's no longer the most abusable and most dangerous drug in its class, but the fact that there are worse drugs doesn't make Darvon a good drug."

Britain banned its version of Darvon in 2005. The FDA, however, may take a more cautious approach, such as requiring stiffer warnings, safety studies or special education efforts aimed at doctors and patients.

The FDA awaited recommendations Friday from a panel of independent advisers.

In an analysis prepared for the hearing, the FDA's safety office said it had searched the agency's database of reported drug problems, but the result was "insufficient" to allow reviewers to make a clear-cut recommendation. The safety office found more than 3,000 reports of serious problems. The top three were suicide, drug dependence and overdoses.