Dapsone in rheumatoid arthritis.

After a preliminary period of observation, 71 patients with consistently active rheumatoid arthritis (RA) were given dapsone 50 mg daily for one week, then 100 mg daily. There was a significant improvement in subjective clinical state and there were significant falls in serum C-reactive protein (CRP) and the ESR; the Rose-Waaler titre (RW) did not fall. The results were compared with those in 78 patients who had gold. Subjective clinical improvement was slower with gold, but from six weeks the pattern of changes in clinical score, CRP and ESR was similar for both drugs. The RW fell during gold treatment. The results suggest dapsone is effective in RA; over-all it appears to be slightly less effective than gold but much less toxic.