Methotrexate intolerance is defined as gastrointestinal and behavioral symptoms occurring before or after methotrexate administration that may lead to treatment discontinuation. 

Dr Claire Dupont-Lucas and colleagues determined the prevalence of methotrexate intolerance in pediatric inflammatory bowel disease (IBD) using the Methotrexate Intolerance Severity Score developed in rheumatology.

In addition, the team identified risk factors for methotrexate intolerance.

Patients with pediatric IBD followed in the IBD clinic of Sainte Justine Hospital who had received methotrexate for IBD between 2004 and 2016, and were still actively on methotrexate, were invited to fill out the Methotrexate Intolerance Severity Score questionnaire. 

The research team used a cutoff score of ≥6 points to define methotrexate intolerance, with at least one point for anticipatory, associative or behavioral items.

The team found that among 102 pediatric patients with IBD, 31% of patients reported symptoms of methotrexate intolerance. 

The research team identified that factors associated with having symptoms of methotrexate intolerance were female sex, receiving a dose of methotrexate higher than 20 mg/wk at the time of the questionnaire, and having active disease according to Physician's Global Assessment.

Prophylactic prescription of antiemetics and folic acid did not prevent symptoms of methotrexate intolerance.

Dr Dupont-Lucas' team comments, "Symptoms of methotrexate intolerance are frequent in pediatric IBD."

"The Methotrexate Intolerance Severity Score questionnaire could help better recognition of these symptoms."

"Identification of risk factors could have important implications for the success of treatment."