Continous Infusion of Ifosfamide without Mesna to prevent Hemorrhagic Cystitis.

Ifosfamide (IFM), an attractive drug for treatment of malignant bone and soft tissue tumors, has hemorrhagic cystitis as the dose limiting factor.Mesna (2-mercaptoethanosulfonate) protects against hemorrhagic cystitis caused by oxazaphoshorine compounds, and high dose administration of IMF with Mesna has been reported in the USA and Europe to be highly effective in the treatment of sarcoma.In Japan a phase two clinical study of Mesna is now underway, but we are not able to use Mesna in our institute. Hemorrhagic cystitis occurred in 5 patients administered a single dose of IMF without Mesna. We then tried continuous administration of ifosfamide to the same patients for three to 7 days to prevent hemorrhagic cystitis. Our study showed that the continuous administration of 1.6gr/M2/day IMF is the limiting dose for preventing hemorrhagic cystitis.