The authors anonymously surveyed 238 outpatients with arthritis from three clinics in the West of England. The patients were all asked about their diagnosis and treatment, and whether they had used any herbal or over the counter remedies within the past six months.

The participants were also asked whether they knew of any possible side effects of the remedies they were taking, interactions with their conventional treatment, and whether they had sought the advice of a healthcare professional before taking the remedy.

44% of the patients had used a herbal or over the counter remedy within the preceding six months. Around a third had taken cod liver oil, and one in five had taken glucosamine and/or chondroitin. Around one in ten had used evening primrose oil.

One in ten was taking remedies that could interact with conventional drugs. These included echinacea, which boosts the risk of liver toxicity when taken with arthritis drugs, and ginkgo biloba, garlic, and devil's claw, all of which increase the risk of bleeding disorders when taken with non-steroidal anti-inflammatory drugs or steroids.

Twenty four of the 26 patients who had put themselves at risk were unaware that they had done so, and ten of them had sought advice from a healthcare professional before opting for complementary treatment.

"Doctors may not recognise the potential adverse effects associated with herbal remedies, and patients may be reluctant to report either the use of herbal remedies or adverse effects," say the authors. "Both patients and prescribers need more information education on the risks and potential interactions of these preparations," they add

Rheumatology outpatients may be at particularly high risk of interactions with conventional drugs, because they are likely to be taking several drugs at the same time and to have other ailments, suggest the authors.; Source: British Medical Journal