Overdose of vinblastine in a child with Langerhans' cell histiocytosis: toxicity and salvage therapy.

The therapeutic index of antineoplastic agents is generally low, therefore, errors in administration can cause severe, life-threatening toxicity. The publication of cases of overdoses may provide useful information on the causes of the mistakes, on drug-induced toxic effects, and on salvage therapy. We report a case of vinblastine overdose in a child affected by Langerhans' cell histiocytosis, Hand-Schüller-Christian syndrome according with the previous classification of histiocytosis X. To our knowledge this is the highest dose of vinblastine ever administered. The child was given salvage therapy with steroids and citrovorum factor. Major side effects were neurologic toxicity (seizures, coma) and marrow aplasia, which improved and gradually resolved beginning day 12.