Both methotrexate (MTX) and gold sodium thiomalate (GSTM) have been shown to be very effective in the treatment of rheumatoid arthritis (RA) and to slow x-ray progression. The combination of both drugs could be useful because of their different and complimentary mechanisms of action. However, there is only one long-term study comparing this combination with MTX monotherapy.
In this prospective long-term observational study, all patients who started MTX treatment from 1980 to 1987 in one center were followed for 12-108 (mean 34.1) months. Ninety-seven patients were treated with MTX, while 126 patients received the combination MTX/GSTM, both drugs being given at the full dose. All patients had active disease, most of them long-lasting destructive RA not responsive to previous disease-modifying antirheumatic drug (DMARD) treatment.
There were no significant differences in the demographic and baseline data between the two groups, with the exception of higher swollen joint counts (SJC) and C-reactive protein (CRP) in the combination group. In both groups the parameters of disease activity (erythrocyte sedimentation rate [ESR], CRP, SJC) improved significantly. A > 50% improvement in the SJC after 1 and 3 years was seen in 62% and 70% of patients in the MTX group, and in 55% and 85% of the patients in the combination group, respectively. A > 50% improvement in the ESR occurred in 54%/63% (MTX group) and in 49%/68% (combination group) for the same timepoints. There was no difference between the groups regarding the nature, frequency, or severity of side effects. A total of 20.6% (MTX) and 15.1% (combination) of patients were withdrawn for side effects. After 5 years, 54% of the patients in both groups were still being treated.
This long-term observational study shows that the combination MTX/GSTM is well tolerated and is at least as effective as MTX single treatment. Taking into account the higher disease activity at baseline and the greater x-ray progression before baseline among the patients in the combination group, one may conclude that combination treatment is superior to monotherapy.