Efficacy of methotrexate in polymyalgia rheumatica in routine rheumatology clinical care.

Background: Current guidelines recommend methotrexate (MTX) as a glucocorticoid-sparing agent in patients with polymyalgia rheumatica (PMR) who relapse or suffer glucocorticoid adverse effects, although there is no level 1 evidence to support this recommendation.

Aims: To review the effect of MTX in PMR on inflammation and glucocorticoid dose.

Methods: Patients with PMR from rheumatology outpatient clinics at two tertiary centres were identified. A structured case note review was conducted for patient characteristics at diagnosis and medications including glucocorticoid and MTX use.

Results: There were 70 patients, 61% female; mean (range) age of 70 (51-87) years. At the time of diagnosis, median (±interquartile range) erythrocyte sedimentation rate (ESR) was 38.5 (26-74) mm/h and C-reactive protein (CRP) 34.5 (6-74 mg/L) with median initiating prednisolone dose of 15 mg (range 5-60 mg). MTX was prescribed in 22 (31%) patients. Mean disease duration at MTX initiation was 2.5 years (1-7 years), with median (range) MTX dose of 10 mg (5-20 mg). At MTX initiation, median (interquartile range) (±standard deviation) ESR was 33 (13-60 mm/h) and CRP 19 (8-42 mg/L). Reasons for commencing MTX were disease relapse (34%) or inability to wean prednisolone dose (66%). Six months after MTX initiation, there was significant reduction in ESR (P = 0.012), CRP (P = 0.0003) and prednisolone dose (P < 0.0001). Eleven (50%) patients stopped MTX, five due to controlled PMR, and six due to adverse effects.

Conclusions: In this study of PMR patients in tertiary care, 31% were co-prescribed MTX, after prolonged disease duration. MTX was associated with improved inflammatory activity and reduced prednisolone dose, with a relatively high risk of adverse events.