Adverse consequences of low-dose methotrexate medication errors: data from French poison control and pharmacovigilance centers.

Objective: The objectives of this study are to carefully describe the context of methotrexate medication errors, to details medical consequences and management approaches, and to determine the rate of fatal outcome.

Methods: Data on methotrexate medication errors were obtained from the French network of poison control and pharmacovigilance centres, which collected and documented reported drug-induced adverse effects. Cases were included if the intake was more than 2-fold the intended weekly dose or a weekly cumulative dose ≥ 30 mg and a follow-up of at least 4 days after the last dose.