Methotrexate (MTX) is still considered the drug of choice in rheumatoid arthritis (RA) management. Comparing subcutaneous (MTX SC) and oral (MTX OR) routes of administration is important to optimize the everyday therapeutic strategy in the real-life setting. This review summarizes scientific evidence currently available on this topic. As shown by pharmacokinetic studies, at the same dose level, bioavailability of MTX SC is significantly higher and less variable than that of MTX OR. This difference is even more pronounced for medium-to-high dosages (i.e., >15 mg/week). With regard to clinical response (Disease Activity Score-28, American College of Rheumatology Criteria), randomized, double-blind studies and retrospective or longitudinal analyses in real-life settings showed that MTX SC is more effective than MTX OR. This is true both in MTX-naive patients with early RA, and in patients who switch from MTX OR to MTX SC due to previous treatment failure, lack of efficacy and/or adverse events. Finally, MTX SC has a better tolerability profile than MTX OR, with fewer gastroenterological side effects. Delaying the use of more expensive biological therapies by switching from MTX OR to MTX SC in non-responders might provide cost savings, with relevant implications in the management of patients with RA.
Funding: Alfa Wassermann.
Keywords: Methotrexate; Oral route; Rheumatoid arthritis; Rheumatology; Subcutaneous route.