THURSDAY, May 31 (HealthDay News) -- Taking the arthritis drug methotrexate in pill form was just as effective as receiving it by injection for the long-term treatment of children with juvenile rheumatoid arthritis, a new study has found.

Since both methods also have a similar incidence of side effects, researchers said the findings suggest that children may as well take the medication as a pill instead of having to put up with the discomfort of injections.

They noted, however, that their study looked back at registry information on kids with arthritis. More research -- including controlled clinical trials, the gold standard of research -- is needed before making a treatment recommendation.

The study, published May 30 in the journal Arthritis Care & Research, was funded by drug maker Wyeth BioPharma.

Methotrexate (brand name Rheumatrex) is one of the most common first-line disease-modifying antirheumatic drug treatments for arthritis.

In this study, German researchers compared more than 150 patients who received methotrexate injections and more than 250 patients who took the drug orally. The male and female patients, who had a median age of 10, all received comparable doses.

After six months of treatment, nearly three-quarters of patients -- including 73 percent receiving injections and 72 percent receiving the pill form -- showed a response to the drug. At least one negative side effect was reported in 27 percent of those receiving injections and 22 percent of those on the oral drug.

Eleven percent of patients receiving injections stopped treatment due to negative side effects, compared with 5 percent of those on oral therapy, the researchers noted.

Juvenile rheumatoid arthritis, also called juvenile idiopathic arthritis, affects between 10 and 100 per 100,000 children younger than 16. It is the most common chronic inflammatory disease in children and can lead to severe disability. About 294,000 U.S. children have the disease, according to the American College of Rheumatology.

One expert in the United States agreed that methotrexate seemed to work equally well regardless of how the children received it.

"Methotrexate is one of the disease-modifying agents used to treat arthritis -- it can be taken as a pill or as a subcutaneous [under the skin] injection and pediatric rheumatologists have felt that the parenteral route (injection) has been the most efficacious," said Dr. B. Anne Eberhard, a pediatric rheumatologist at Cohen Children's Medical Center in New Hyde Park, N.Y. However, she added, "this study from Germany suggests otherwise."

Still, while some children did experience "significant improvement in their arthritis" with methotrexate, most patients "did not achieve remission in their illness, which is the ultimate aim in treating children with juvenile idiopathic arthritis," Eberhard noted.

More information

The Nemours Foundation has more about juvenile rheumatoid arthritis.