Urine mesna excretion after intravenous and oral dosing in ifosfamide-treated children

Abstract

Purpose: To describe mesna excretion in children.

Patients and methods: We studied 14 children (aged 1-18 years) who received 1.8 g/m(2) of ifosfamide per day for 5 days. For uroprotection, the children were given intravenous mesna (equal to 20% of the ifosfamide dose) followed by two oral doses (each equal to 40% of the ifosfamide dose). The concentrations of mesna and the metabolite dimesna were measured in urine samples collected on treatment days 1 and 5.

Results: Of 14 patients enrolled, 11 (aged 4-18 years) were evaluable. The profiles of mesna excretion rates were similar on days 1 and 5. Mesna excretion declined rapidly over 1-2 h after intravenous dosing. Increases in mesna excretion after oral dosing lagged by 2-4 h. About 21% of the mesna administered was excreted unchanged over 24 h on both days 1 and 5. The proportion excreted varied by severalfold between patients, but there was no association with age.

Conclusion: The profile of mesna excretion after intravenous and oral dosing in these children was similar to that in reported studies of ifosfamide-treated adults.