A drug often used to treat rheumatoid arthritis - methotrexate - seems to improve a condition known as ankylosing spondylitis, Mexican researchers report.

Ankylosing spondylitis resembles arthritis, but the chronic inflammation is confined mainly to the spine and can lead to actual fusion of the joints.

In a 24-week trial, Dr. Laura Gonzalez-Lopez, of Hospital General Regional, in Guadalajara, and colleagues compared the efficacy of methotrexate to an inactive placebo treatment in patients with active ankylosing spondylitis.

As described in The Journal of Rheumatology, the team measured a combination of factors such severity of morning stiffness, physical well-being, and clinical assessment of disease activity to evaluate the response to treatment.

A total of 17 participants were given methotrexate and 18 received the placebo. One methotrexate patient was dropped from the trial because of lack of compliance and one placebo patients withdrew due to lack to response.

After 24 weeks, 53 percent of those taking methotrexate and 17 percent those taking placebo showed significant improvement.

The rate of side effects was similar between the groups, and no serious adverse effects were seen.

Methotrexate could be useful for people with ankylosing spondylitis, Gonzalez-Lopez and colleagues conclude, because many don’t respond to standard treatment with sulfasalazine, and the newer anti-rheumatic drugs are expensive.

However, they add, “Further studies are needed to determine the long-term effects of methotrexate, its relative potency, and safety in regard to other disease modifying antirheumatic drugs.”

SOURCE: Journal of Rheumatology, August 2004.