Combination DMARD treatment with parenteral gold and methotrexate

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 A total of 20.6% (MTX) and 15.1% (combination) of patients were withdrawn for side effects.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.