Objectives: Methotrexate (MTX) is one of the most frequently used, highly effective disease-modifying drugs in juvenile idiopathic arthritis (JIA) therapy. The drug can be administered orally or subcutaneously, but the efficacy and tolerance of these two routes of administration raise doubts in JIA patients. The aim of the study was to evaluate MTX efficacy and tolerability after switching from the oral to the subcutaneous route of administration in children with JIA.
Material and methods: A single-centre, questionnaire-based assessment of MTX efficacy and tolerance in 126 unselected JIA patients with longer than 6 months of follow-up was performed. In all patients, MTX was initially administered orally. The response to MTX treatment was analysed according to American College of Rheumatology (ACR) paediatric criteria.
Results: Six-month MTX therapy was effective (ACR score ≥ 30) in 83 children (65.9%). The oral route of MTX administration was changed to subcutaneous in 32 patients after a mean period of 14 months due to intolerance (n = 20) or reluctance to take the oral formulation (n = 12). This group of children was significantly younger (p = 0.02) but did not differ from the group of children that continued oral treatment in other aspects, including MTX dose. Six months after switching from oral to subcutaneous MTX the ACR score remained unchanged. Three children (9.4%) still reported symptoms of drug intolerance.
Conclusions: The switch from oral to subcutaneous MTX may increase the response rate in JIA patients with intolerance of its oral formulation. The reluctance to take oral MTX can be anticipated in early childhood, and should be considered in the individualization of therapy, having also in mind the lower risk of severe gastrointestinal adverse drug reactions.
Keywords: juvenile idiopathic arthritis; methotrexate; oral administration; subcutaneous administration.