Abstract
Methotrexate at low doses (5-25 mg/week) is first-line therapy for rheumatoid arthritis. However, there is inter- and intrapatient variability in response, with contribution of variability in concentrations of active polyglutamate metabolites, associated with clinical efficacy and toxicity. Prescribing remains heterogeneous across population groups, disease states and regimens. This review examines current knowledge of dose-response of oral methotrexate in the setting of rheumatoid arthritis, and how this could help inform dosage regimens.