To determine the long-term efficacy and safety of weekly low-dose methotrexate (MTX) in rheumatoid arthritis (RA).
Fifty-one patients receiving MTX for RA were prospectively studied over a mean treatment period of 36 months. Standard clinical and laboratory measures of disease activity were assessed by the same investigator at baseline, and at 3, 6, 12, 24 and 36 months.
The overall probability of continuing to take MTX was 80.3% at 12 months, 74.5% at 24 months, and 70.5% at 36 months. Of the 36 patients who completed 36 months of therapy, a significant improvement was noted compared to baseline in all of the clinical disease variables and acute phase reactants, with a steroid-sparing effect. There were no significant differences in these parameters between the 36-month visit and the 24- or 12-month visit. Adverse events occurred frequently (80.3%), but only 15.6% of the patients discontinued MTX permanently. Four patients (7.9%) withdrew due to a lack of efficacy.
Our findings indicate that MTX remains effective over 36 months of therapy, with an acceptable toxicity profile.