Toxicity of sulphasalazine in rheumatoid arthritis. Possible protective effect of rheumatoid factors and corticosteroids.

Adverse reactions to sulphasalazine were seen in 35 of 100 patients with rheumatoid arthritis. Gastrointestinal side effects, skin reactions and increases of serum liver enzymes were most frequently noted. Serious or fatal adverse reactions were not observed. The frequency of toxicity to sulphasalazine was significantly lower among patients treated concurrently with small doses of oral corticosteroids, and also among cases seropositive for rheumatoid factors. Of the 14 seropositive patients also treated with corticosteroids, none developed side effects to sulphasalazine.