Oral gold: a comparison with placebo and with intramuscular sodium aurothiomalate

The therapeutic and toxic effects of the orally absorbed gold compound auranofin have been compared with placebo and parenterally administered sodium aurothiomalate (GST) in 90 patients with active rheumatoid arthritis over one year. At the end of this period 57% of patients on auranofin, 73% on GST and 0% on placebo remained on therapy. Toxicity caused discontinuation of therapy in 10% of patients on auranofin, 20% on GST and 7% on placebo. Lack of response to therapy led to withdrawal of 20% on auranofin, 0% on GST and 90% on placebo. Multiple clinical and biochemical assessments were performed during this study. Analysing them separately, and in the case of 6 of them grouped together in a disease activity index, the same trend is apparent throughout, namely that placebo has no effect on active inflammatory rheumatoid arthritis, and that both gold drugs are beneficial. GST has an earlier effect and tends to produce a greater change but after one year there was no significant difference between the 2 gold drugs for any parameter assessed. Gold levels in plasma or erythrocytes did not predict or correlate with either the development of toxicity or clinical efficacy. This study has demonstrated the second-line potential of auranofin which seems to be effective at gold concentrations in the blood below those observed with GST therapy. Toxicity limits the use of gold salts in RA. If the reduced incidence of adverse reaction with auranofin observed in this study is substantiated in larger numbers over prolonged periods, the use of gold at an earlier stage of disease may be facilitated.