Medical Uses
Voraxaze (glucarpidase) is a carboxypeptidase used to reduce toxic plasma methotrexate concentration (greater than 1 micromole per liter) in adult and pediatric patients with delayed methotrexate clearance (plasma methotrexate concentrations greater than 2 standard deviations of the mean methotrexate excretion curve specific for the dose of methotrexate administered) due to impaired renal function.
Limitations of Use: This therapeutic drug is not recommended for use in those who exhibit the expected clearance and expected plasma methotrexate concentration. Reducing plasma methotrexate concentration in these populations may cause subtherapeutic exposure to methotrexate.
Recommended Dosage:
The recommended dosage of Glucarpidase is 50 Units per kilogram (kg) as a single intravenous (IV) injection administered over 5 minutes. Flush the intravenous (IV) line before and after administration. For the initial 48 hours after the dose of Glucarpidase, administer the same leucovorin dose given before Glucarpidase. Administer leucovorin at least 2 hours before or 2 hours after the dose of Glucarpidase. Beyond 48 hours after the dose of Glucarpidase, administer leucovorin based on the measured methotrexate concentration. Continue leucovorin until the methotrexate concentration has been maintained below the leucovorin treatment threshold for at least 3 days.