The following topics have been selected to raise awareness and, in some cases, to stimulate reporting of similar adverse reactions.
Methotrexate is a folate antagonist used in the treatment of cancer and autoimmune diseases such as psoriasis and rheumatoid arthritis.Footnote 1 As a high-alert medication, methotrexate carries an increased risk of significant, even fatal, consequences when it is used in error.Footnote 2
Health Canada is aware of recent serious errors reported in the media in which patients received daily instead of weekly doses of oral methotrexate. Patient safety organizations and regulators have issued a number of notices reporting similar errors in the past.Footnote 3,Footnote 4,Footnote 5
Health Canada’s recently published Good Label and Package Practices Guide for Prescription Drugs includes direction to manufacturers regarding the inclusion of prominent warning statements on labels. The guide suggests that labels for oral methotrexate should state “check dose and frequency – methotrexate is usually taken once a week.” Health Canada will continue to investigate whether additional label changes could help to mitigate the potential for error.
Healthcare professionals are reminded that the risks associated with methotrexate dosing errors require vigilance at all stages of the medication use process. The importance of taking the medication as prescribed should be clearly communicated to patients and caregivers.
Methotrexate [product monograph]. Kirkland (QC): Pfizer Canada Inc.; 2016.
ISMP List of high-alert medications in community/ambulatory healthcare. Horsham (PA): Institute for Safe Medication Practices; 2011 January 30. (accessed 2017 January 18)
Severe harm and deaths associated with incidents involving low-dose methotrexate. ISMP Canada Safety Bulletin 2015;15(9):1-5. (accessed 2017 January 18)
Stewart I. Errors involving oral methotrexate. Pharmacy Connection 2015;22(4):54-5. (accessed 2017 January 18)
Incidents of inadvertent daily administration of methotrexate. ISMP Canada Safety Bulletin 2008;8(2):1-3. (accessed 2017 January 18)