October 27 (HealthDay News) -- The drugs etanercept and methotrexate are safe and effective for long-term, continuous treatment of juvenile rheumatoid arthritis, new research finds.

In a three-year study that enrolled about 600 patients, aged 2 to 18, some of the children took methotrexate alone, others took etanercept alone, and another group took both drugs. Etanercept was given as either a 0.4 mg/kg injection twice weekly or 0.8 mg/kg weekly, and methotrexate was given as dose greater than or equal to 10mg/m2 once a week.

The researchers assessed the safety of the treatments by monitoring the occurrence of serious side effects, such as medically important infections and death. They determined the overall effectiveness of the medications by assessing the patients' joints and overall health.

During the study, one patient taking methotrexate developed lupus, and two cases of sepsis occurred in patients taking etanercept and the combination treatment. There were no cases of lymphoma, malignancy, tuberculosis or death.

"Determining the safety of these agents was the primary goal; serious adverse events and medically important infections were prospectively and systematically collected in 594 patients representing over 1,200 years of exposure," researcher Dr. Norman T. Ilowite, chief of the division of rheumatology, Children's Hospital at Montefiore, and professor of pediatrics at the Albert Einstein College of Medicine in the Bronx, said in an American College of Rheumatology news release.

"These data suggest that etanercept, alone or in combination with methotrexate, is safe as long-term continuous therapy for the treatment of juvenile rheumatoid arthritis," he said.

The study was expected to be presented Tuesday at the American College of Rheumatology annual meeting, in San Francisco.

SOURCE: American College of Rheumatology, news release, Oct. 25, 2008