Abstract: Methotrexate (MTX) remains the cornerstone therapy for patients with rheumatoid arthritis (RA), with well-established safety and efficacy profiles and support in international guidelines. Clinical and radiologic results indicate benefits of MTX monotherapy and combination with other agents, yet patients may not receive optimal dosing, duration, or route of administration to maximize their response to this drug. This review highlights best practices for MTX use in RA patients. First, to improve the response to oral MTX, a high initial dose should be administered followed by rapid titration. Importantly, this approach does not appear to compromise safety or tolerability for patients. Treatment with oral MTX, with appropriate dose titration, then should be continued for at least 6 months (as long as the patient experiences some response to treatment within 3 months) to achieve an accurate assessment of treatment efficacy. If oral MTX treatment fails due to intolerability or inadequate response, the patient may be “rescued” by switching to subcutaneous delivery of MTX. Consideration should also be given to starting with subcutaneous MTX given its favorable bioavailability and pharmacodynamic profile over oral delivery. Either initiation of subcutaneous MTX therapy or switching from oral to subcutaneous administration improves persistence with treatment. Upon transition from oral to subcutaneous delivery, MTX dosage should be maintained, rather than increased, and titration should be performed as needed. Similarly, if another RA treatment is necessary to control the disease, the MTX dosage and route of administration should be maintained, with titration as needed.
Keywords: bioavailability, dosing, gastrointestinal, polyglutamation, subcutaneous