Assessment of oral methotrexate intolerance in Japanese adult patients with rheumatoid arthritis.

ABSTRACT

AIM: The objective of this study was to assess the gastrointestinal side (GI) effects of oral methotrexate (MTX) in Japanese adult patients with rheumatoid arthritis (RA). METHODS: In this single-center retrospective study, 112 Japanese adult patients (over 18 years old) with RA were examined by Methotrexate Intolerance and Severity assessment in Adults (MISA) questionnaire. RESULTS: Forty-five (40.2%) of patients were MTX intolerant (MISA score ≥1). Twelve patients (11.2%) were moderate-to-severe MTX intolerant (MISA cross-product score ≥4). The most common GI side effects of MTX were gastric discomfort (26.8%), followed by loss of appetite or dysgeusia (14.3%), fatigue and lethargy (12.5%), and nausea (10.7%). CONCLUSIONS: Japanese adult patients with RA showed a high prevalence of MTX intolerance even in low-dose oral MTX. The MISA questionnaire was practical for finding patients with MTX intolerance.