Efficacy of methotrexate in polymyalgia rheumatica in routine rheumatology clinical care

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.

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

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.

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.

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.