[Severe methotrexate poisoning].

Methotrexate toxicity is rare but extremely severe. When complete, it consists of ulcerations of the gastrointestinal mucosae responsible for necrotizing enteritis, erythroderma, bone marrow aplasia, interstitial pneumonia, hepatitis and organic renal failure with diuresis. Toxicity is facilitated by pre-existing renal impairment, third sector and abstention or underdosage of foliculinic acid prescribed as antagonist. The diagnosis rests on serum assays, the results of which must be interpreted taking into account the assay method and the time elapsed between the injection of methotrexate and its assay in serum. The multivisceral pathology observed may totally regress, as in the case reported here. Treatment is based on symptomatic measures, starting with maintenance of an abundant and alkaline diuresis, and on the parenteral administration of folinic acid in doses that vary with the authors.