Standard dose ifosfamide is a dose < 2.5 g per square meter BSA per day. This is given as an infusion.
Total dose of mesna given:
(1) 60% of ifosfamide dose based on weight if all of the mesna is given by infusion.
(2) 100% of ifosfamide dose based on weight if some mesna is given by infusion and the rest orally.
(2a) 20% of those total dose is given as an IV bolus before the ifosfamide
(2b) 80% of the total dose is given as oral tablets after the ifosfamide
Administration of mesna as an infusion for ifosfamide given as a short infusion:
(1) A third of the total dose is given as an IV bolus 15 minutes for the ifosfamide infusion.
(2) A third is given as an IV bolus 4 hours after the ifosfamide infusion.
(3) A third is given as an IV bolus 8 hours after the ifosfamide infusion.
Administration of mesna as an infusion for ifosfamide given as a continuous infusion:
(1) A third is given as an IV bolus 15 minutes for the ifosfamide infusion is started.
(2) The remaining mesna is given as an infusion that is started with the ifosfamide and this is continued for 12 to 24 hours after the ifosfamide infusion is completed.
Administration of mesna as an infusion and oral dose for ifosfamide given as a short infusion:
(1) 20% of the total dose is given as an IV bolus 15 minutes for the ifosfamide infusion.
(2) 40% of the total dose is given as oral tablets 2 hours after the ifosfamide infusion.
(3) 40% of the total dose is given as oral tablets 6 hours after the ifosfamide infusion.
where:
• Oral dosing allows the patient to go home after the ifosfamide infusion is complete.
• The oral dose is twice the intravenous dose to compensate for decreased bioavailability.
• The oral dose is given on a schedule sooner than the intravenous bolus to allow for absorption from the GI tract.
• If the patient vomits within 2 hours of taking an oral dose then the either the oral dose should be repeated or an IV bolus should be given (using the lower IV dose).
