Trend of Methotrexate Dosage and Adverse Effects in Patients with Rheumatoid Arthritis in Our Institutes in the Last Decade

Abstract

Objective: Methotrexate (MTX) drastically improved rheumatoid arthritis (RA) therapy when introduced in Japan from 1999 onwards, especially after permitting the increase to the maximum dosage of 16 mg per week from the year 2011. The use of MTX for patients with RA may reflect trends in disease severity, management and health outcomes.
Methods: We examined the number of patients who had taken MTX, the mean dosage of the drug and associated adverse effects in our patient cohort from the last decade.
Results: The total dosage of MTX increased from 185 mg/person/year to 546 mg/person/year. We had a total of 552 patients in our clinics by 2012. The percentage of patients who had been treated with MTX was 49.0% (264/552). The mean dosage per week had increased from 4.9 mg/week in 2002 to 10.7 mg/week in 2012. Adverse effects occurred in 14 patients, all of whom were hospitalized.
Conclusion: The mean dosage of MTX for patients with RA has increased year by year. It may play an important role for improvement of disease activity and attitudes, and quality of life in patients with rheumatoid arthritis.