Intraarticular progesterone: effects of a local treatment for rheumatoid arthritis.

The antiinflammatory effect of a single intraarticular injection of progesterone was investigated in 12 patients with rheumatoid arthritis. A local, but no systemic decline of inflammation was observed in 10 of them for at least one month. The average local scores of inflammation at Days 7, 14, 21 and 30 after injection were significantly lower than pretreatment scores (p less than 0.000003 for each comparison). In some patients the effect continued for up to 2 months. No important side effects were observed during the following 2 months. However, a more prolonged followup of treated patients is necessary to rule out the late onset of side effects.