Influence of High-Dose Folic Acid on Methotrexate Efficacies and Safety in Japanese Rheumatoid Arthritis Patients.

Folic acid dose at ≦5 mg/week has been recommended for rheumatoid arthritis (RA) patients to decrease risk of methotrexate adverse effects. However, higher doses of folic acid is used in some cases. We examined the influence of high-dose folic acid on methotrexate efficacies and safety in Japanese RA patients.