The widely used pain reliever ibuprofen doubles the risk of ulcers, a study published this week said. But its lead author said ibuprofen still may be the best choice for people with severe arthritis.

The Vanderbilt University study confirms the increased risk of ulcers in people who used analgesics belonging to a class called non-steroidal anti-inflammatory drugs, or NSAIDs, many of which are available only by prescription.It also found the overall risk increased with higher doses and was greatest in the first month of use.

Ibuprofen, available without a prescription since 1985, had the lowest ulcer risk among the dozen NSAIDs studied. Researchers said that for those suffering chronic pain and inflammation, ibuprofen may be the best choice.

The researchers did not study aspirin, also an NSAID, because it is not a prescription drug, but said it is at least as risky as ibuprofen. Acetaminophen, used in the pain reliever Tylenol, is not an NSAID and is not associated with ulcers.

One of the earliest investigators of the link between NSAIDs and ulcers, Dr. Sanford Roth of the Arthritis Center in Phoenix, called the Vanderbilt study "an important paper" that "corroborates that lower doses do make a difference."