Clarithromycin in rheumatoid arthritis: the addition to methotrexate and low-dose methylprednisolone induces a significant additive value--a 24-month single-blind pilot study.

To compare the efficacy of the addition of clarithromycin (CM) to methotrexate (MTX) and methylprednisolone (MP) in active rheumatoid arthritis (RA). 32 patients with RA consecutively randomized. Control group: sixteen patients treated for 24 months with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily. CM group: sixteen patients treated with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily for 24 months; CM therapy added in the first month (500 mg twice a day for the first 15 days followed by 500 mg a day for the remaining 15 days). Evaluation of the improvement following ACR criteria was performed at months 1 (primary endpoint), 3 and 6. Patients were furthermore observed after 12, 18 and 24 months from the study beginning. At month 1, following ACR70 improvement criteria, we found a significant additive value in CM group (10/16 = 63% vs 4/16 = 25%, p = 0.033--chi-square test). After discontinuation of CM, the difference between groups was anymore evident (month 3: CM group 10/16 = 63% vs control group 9/16 = 56%). At month 24, 7/16 (44%) in control group and 12/16 (75%) in CM group completed the follow-up. The addition of CM to MTX and MP can induce the remission ACR 70 in the majority of RA patients within 4 weeks, while MTX and MP alone need about 3 months to achieve the same result.