Key points

  • We recommend to consult your poison centre with the use of this antidote.
  • Use the IV route only and never use the intrathecal route.
  • Folinic acid or leucovorin, the biologically active forms of folic acid, must be used for reversing toxicity due to dihydrofolate reductase inhibitors (methotrexate).
  • Methotrexate toxicity, when used for a non-oncological indication, is directly related to the duration of exposure and less dependent on the methotrexate concentration. For example, patients with reduced renal function or prolonged exposure are more at risk of toxicity.
  • Folic acid, can be used interchangeably with folinic acid or leucovorin only in cases of methanol poisoning.
  • Folic acid or leucovorin facilitates the conversion of formates (toxic) resulting from the metabolism of methanol.
  • Leucovorin contains calcium: rapid intravenous administration can result in complications.

Last updated : 2022-02-17