Long-term prospective study of the use of methotrexate in the treatment of rheumatoid arthritis. Update after a mean of 90 months

Abstract

Objective: To determine and describe the clinical, radiographic, and toxicity profile in a cohort of rheumatoid arthritis patients receiving weekly oral methotrexate (MTX) over a mean period of 90 months, and to compare and contrast these data with our previous data on this cohort, reported after 53 months.

Methods: Prospective, open observational study over a mean treatment period of 90 months (range 79-107 months). Standard clinical and laboratory measures of disease activity were assessed by the same investigator at baseline, 1 month, 3 months, and every 3 months thereafter.

Results: A significant improvement from baseline was maintained in all clinical parameters but the number of tender joints. Toxic reactions were as common in months 54-90 as during the first 53 months. The mean dosage of MTX decreased from 14.6 mg/week at the time of the last report to 11.7 mg/week, while the mean prednisone dosage increased from 1.9 mg/day to 2.1 mg/day. Radiographic scores for erosive disease became statistically significantly different from baseline at year 8, and scores for joint space narrowing differed significantly from baseline at years 5 and 8. Since study entry, 2 patients (6.9%) have experienced MTX pneumonitis.

Conclusion: We conclude that a majority of rheumatoid arthritis patients are able to continue MTX treatment with generally sustained efficacy, for intervals that meaningfully exceed those reported previously.