WASHINGTON - Experts advising the government decided there is a real risk of heart damage from some of the most effective and popular prescription drugs to ease the pain chronic diseases such as arthritis.

But those federal advisers, after three days of meetings last week, said the drugs offer enough benefits to let a patient and his doctor decide on their use. The scientists also recommended additional warnings for the drugs and further study.

In question and answer form, here's a

look at the dilemma facing patients:

QUESTION: Which drugs are in question?ANSWER: A group of drugs called Cox-2 inhibitors, which ease pain by hampering the activity of the Cox-2 enzyme. Those approved for sale are Celebrex, Bextra and Vioxx - all big sellers in recent years. Drugs in this class usually have little effect on the stomach, making them popular with people whose stomachs were sensitive to aspirin, ibuprofen and similar nonsteroidal anti-inflammatory drugs.

QUESTION: What is the problem?ANSWER: Heart troubles and strokes. A long-term study showed people taking Vioxx had an increase in heart attacks and strokes. Drug maker Merck & Co. stopped sales of Vioxx in the fall. Since then similar reports have surfaced about Pfizer Inc.'s Celebrex and Bextra.

QUESTION: Why not use other painkillers?ANSWER: Many of them, especially for those using them over long periods, can cause serious stomach damage and bleeding, which can also be life-threatening.

QUESTION: How serious is the heart problem?ANSWER: Dr. Alistair J.J. Wood of Vanderbilt University School of Medicine said the increase in heart problems is about 1 percent for people using Celebrex and higher for Bextra and Vioxx. The reported risk varied from study to study. "The data are very compelling, Vioxx is substantially worse than the others," Wood said.

QUESTION: But that does not sound so bad - 1 percent.ANSWER: These drugs are taken by millions of people, so even a small added risk can translate into thousands of heart attacks and strokes.

QUESTION: What did the medical advisers recommend?ANSWER: They concluded, unanimously, that all three drugs pose at least some risk. But the experts also thought the drugs provide enough benefits that people who need them ought to have that right.

QUESTION: Were they unanimous about having all the drugs available?ANSWER: No. The vote was 31-1 to keep Celebrex on the market. They were less sure about the others, approving the sale of Bextra by a 17-13 margin with two abstentions, saying in a 17-15 vote that Vioxx should be available.

QUESTION: Does that mean that Vioxx will go back on sale?ANSWER: Because Merck voluntarily withdrew it from the market, Vioxx is still an approved drug. Company officials said they might consider putting it back on sale now that they have learned the heart problems are not unique to their product. They are expected to have discussions with the FDA before making a decision. Vioxx had the best evidence for reducing stomach and intestinal problems.

QUESTION: What about Celebrex and Bextra?ANSWER: They remain on sale. The advisers did suggest adding label warnings, providing consumer with brochures and taking other steps to ensure people understand the risks. Some experts questioned whether there was evidence these drugs really do reduce stomach problems.

QUESTION: What should someone with chronic pain do?ANSWER: Dr. John Jenkins, director of the FDA's office of new drugs, said that is up to a patient and his doctor. Has the patient had a heart attack or is he at risk because of obesity or high blood pressure? Has he had stomach problems or bleeding? In addition, some drugs work well in one person and not someone else, for reasons unknown.

QUESTION: Will the FDA follow the recommendations of the advisory panels?ANSWER: The agency does not have to, but most often does. Jenkins said the FDA will study the recommendations and respond in a few weeks. When the advisers are closely divided, as they were on Bextra and Vioxx, the FDA considers that.

QUESTION: At the meetings, did people who need pain relief have their say?ANSWER: They had a chance to express their opinion. One woman said she felt like Celebrex was created for her and let her resume a normal life. "Vioxx gave me my life back," another woman said.

QUESTION: Was there discussion of other pain drugs?ANSWER: Yes. The panel said it would like to see studies of the safety of non-Cox-2 drugs. There are more than 20 such drugs on the market such as ibuprofen, naproxen and even aspirin.