Background: Bromocriptine, as an Ergot alkaloid, suppresses prolactin synthesis. Some clinical studies support the role of prolactin in the development of rheumatoid arthritis (RA) disease activity. Therefore, this study aimed to examine the effect of bromocriptine on disease activity in RA.

Materials and Methods: This double-blind interventional study was performed on 174 patients with rheumatoid arthritis referred to Shahid-Beheshti hospital in Kashan during 2011-2012. The patients were allocated into the two groups through block randomization. One group received bromocriptine 2.5 mg two times a day and another group received a placebo. All patients were examined at the beginning and during the second and six months of the study for swelling, tenderness, pain severity based on disease activity score (DAS), erythrocyte sedimentation rate (ESR) and visual analogue scale (VAS), respectively.

Results: Results indicated that in bromocriptin group, initial swelling, pain severity and initial DAS significantly decreased from 3.7 to 0.59 82.1 to 23.15 3.8 to 3.5, respectively after 6 months compared with those in the control group. Moreover, no significant decrease was observed in the ESR and tenderness parameters.

Conclusion: Bromocriptine can reduce swelling, pain severity and DAS in RA.