Many arthritis sufferers take herbal supplements, but few know about potentially dangerous interactions with traditional arthritis drugs.

Almost half of the arthritis patients questioned in a survey said they had taken an herbal supplement or other dietary supplement within the preceding six months. But only a quarter of those who had taken herbal supplements known to interact with the drugs they were taking were aware that they were putting themselves at risk.

And many patients who were unknowingly taking a potentially dangerous mix of over-the-counter herbal supplements and arthritis drugs said they had been told by a health professional that it was OK.

"That was one of the most troubling things we heard," researcher Wendy Holden, MD, tells WebMD. "Patients said they had asked their physician or pharmacist about potential interactions and had been told there was no cause for concern."

Confusing Times

These are confusing times for people with arthritis trying to decide on treatment. Two of the three most widely prescribed anti-inflammatory arthritis drugs — Vioxx and Bextra — have been taken off the market due to concerns about heart attack and stroke risk. And there are growing concerns about the long-term safety of other prescription and over-the-counter pain relievers.

Illinois rheumatologist Erin Arnold, MD, says she has seen a big increase in patients who are eager to try alternative treatments for pain relief over the past few months.

"People are very wary right now of medical recommendations and of the established medications in general because they have been bombarded by the negative press about these drugs," she tells WebMD.

Fish Oil, Glucosamine OK

In the new study, researchers anonymously surveyed 238 arthritis patients from three clinics in England about the arthritis drugs they took and about their use of dietary supplements. They were also questioned about their knowledge of possible interactions between the supplements and drugs they took.

The findings are published in the latest issue of the Annals of The Rheumatic Diseases.

Of the 44 percent of patients who reported taking a dietary supplement during the previous six months, one in three had taken cod liver oil and one in five had taken glucosamine and/or chondroitin.

Some studies show that fish oil, glucosamine, and chondroitin slow the progression of arthritis caused by inflammation.

These supplements are generally considered safe in terms of interactions with other arthritis drugs. But one out of 10 patients surveyed reported taking supplements known to interact with conventional arthritis treatments.

Herbs to Watch Out For

Five of the 120 patients taking disease-modifying antirheumatic drugs like methotrexate increased their risk of liver toxicity by also taking the herbal supplement echinacea.

And 10 percent of the patients who took nonsteroidal anti-inflammatory drugs, which are associated with an increased risk of bleeding problems, took supplements that further increased this risk. The herbals included ginkgo biloba, garlic, and devil's claw.

Supplements Have a Place in Treatment

Arnold agrees that patients need to be careful when they combine conventional arthritis drugs with dietary supplements. But she says it is increasingly clear that supplements and other alternative therapies have a legitimate place in arthritis treatment.

Late last year, a U.S. government research team put its stamp of approval on the ancient Chinese therapy acupuncture for the treatment of osteoarthritis of the knee.

And Arnold says she has had great success treating patients who got little relief from traditional anti-inflammatory pain relievers with a combination of anti-inflammatory supplements and foods, such as omega-3-rich salmon.

She tells WebMD that while interactions can occur, the risk of any treatment approach can be minimized if the patient and doctor work closely together to develop an appropriate treatment strategy.

"There has been so much negative press that people are afraid to take anything," she says. "But it is important not to make broad, sweeping statements about any of the treatments. It is really up to the patient and physician to come up with a risk/benefit ratio that works."

By Salynn Boyles, reviewed by Michael W. Smith, MD

SOURCES: Holden, W. Annals of the Rheumatic Diseases, April 2005; vol 64: pp 790, Wendy Holden, MD, Nuffield Orthopaedic Centre, Oxford, U.K. Erin Arnold, MD, Illinois Bone and Joint Institute; medical advisor, Arthritis Foundation.