Ifosfamide-induced encephalopathy with or without using methylene blue.

Ifosfamide is one of the most widely used alkylating chemotherapeutic agents. Before mesna was introduced, its dose-limiting toxicity was hemorrhagic cystitis, but at present, neurotoxicity is one of its most worrisome side effects. A total of 10%-15% of patients treated with ifosfamide develop an encephalopathy. The exact pathophysiologic mechanisms responsible for the development of ifosfamide-induced encephalopathy (IIE) are not known. However, accumulation of chloracetaldehyde, toxic metabolite of ifosfamide, in the central nervous system is theorized to be the cause of the neurotoxicity. No standard treatment has been available for IIE. Recently, many reports suggested that methylene blue (MB) may be an effective treatment of this lethal complication. We report two cases of IIE and their treatment outcomes. The first patient recovered completely with MB. The other patient showed slow and incomplete improvement without using MB. We suggest that MB can be used as an initial treatment for the encephalopathy related to ifosfamide infusion. Thus, we present these two cases with brief review of related literature.