It can be frightening for parents and children when a stiff joint or sore knee turns into a diagnosis of juvenile arthritis. Luckily, there are a variety of different medications to control the disease and ease pain. An international team of researchers compared two drugs from a class of drugs called disease-modifying antirheumatic drugs (DMARDs), which are used to treat rheumatoid arthritis.

What the researchers wanted to know: Which works better in treating juvenile rheumatoid arthritis, methotrexate or leflunomide?

What they did: The researchers split a group of about 90 children between the ages of 3 and 17 into two groups, half of them took methotrexate, and half took leflunomide (sold under the brand name Arava). The patients were examined by a doctor at the beginning of the study and then every four weeks for four months. The researchers measured the patients' improvement by using a criterion called the American College of Rheumatology Pediatric core set of disease activity measures (the ARC Pedi 30). According to that criteria, in order to be considered effective, a medication must improve a patient's arthritis by 30 percent in three out of six measures of joint swelling and disease severity. They also evaluated medication effectiveness using a scale called the percent improvement index, which measures changes in disease severity as a percentage of symptom improvement.

What they found: Both medications helped ease the children's symptoms, but methotrexate worked slightly better than leflunomide. There was no difference in how the medications decreased disease severity on the percent improvement index; there was a 50 percent improvement in both groups. In the methotrexate group, 89 percent of the participants improved enough to meet the ARC Pedi 30 criteria; 68 percent of the patients taking leflunomide met those same criteria. There were some safety concerns. Three patients (6 percent) in the leflunomide group had serious side effects and two had to be withdrawn from the study because of those side effects. Patients in both groups had higher than normal concentrations of an enzyme released by the liver—meaning the organ is under stress—though patients taking methotrexate were more likely to have high concentrations than the other group.

What it means to you: Both drugs can be used to control juvenile rheumatoid arthritis. Methotrexate was more effective than leflunomide, although it may also be harder on the liver. These drugs are stronger than the common first line of defense against juvenile arthritis, nonsteroidal anti-inflammatory drugs (NSAIDs). But, because they can have serious side effects, they should be used only under the supervision of a doctor.

Caveats: The company that makes leflunomide funded this study. However, since leflunomide wasn't the clear winner, it's hard to argue that the study was biased.

Find out more: Basic information about juvenile arthritis can be found at the Nemours Foundation's KidsHealth website.

The National Institutes of Health has a web page that has lots of links to find information about the disease. To find out specifically about the drugs used to treat juvenile arthritis, check out the Arthritis Foundation.

Read the article: Silverman, E. et al. "Leflunomide or Methotrexate for Juvenile Rheumatoid Arthritis." New England Journal of Medicine. April 21, 2005, Vol. 352, No. 16, pp. 1655–1666.

Abstract online: http://content.nejm.org