Mathematical modeling -- guide to high-dose methotrexate infusion therapy.

Area of Science:

• Pharmacokinetics and Mathematical Modeling
• Oncology Drug Dosing
• Clinical Pharmacodynamics

Background:

• High-dose methotrexate infusion therapy requires careful dose management to optimize efficacy and minimize toxicity.
• Accurate prediction of methotrexate plasma concentrations is crucial for guiding dose adjustments and rescue therapy.
• Existing pharmacokinetic models may need refinement for personalized dose escalation strategies.

Purpose of the Study:

• To refine a mathematical model for guiding dose escalation in high-dose methotrexate infusion therapy.
• To utilize a computational program for patient-specific model parameter adjustment.
• To simulate various dose escalations and predict methotrexate plasma concentrations.

Main Methods:

• A mathematical model describing methotrexate pharmacokinetics was refined.
• Patient-specific model parameters were adjusted using the SAAM computer program based on plasma concentrations.
• The model was used to simulate dose escalations and predict plasma concentrations.
• Observed plasma concentrations were compared to predicted values to assess model accuracy.

Main Results:

• The refined mathematical model successfully predicted plasma concentrations in patients receiving high-dose methotrexate infusions.
• The model demonstrated utility even in patients with abnormal creatinine clearances.
• The simulation capability allowed for comparisons between different infusion durations (e.g., 24-hour vs. 6-hour).

Conclusions:

• The refined pharmacokinetic model serves as a valuable guide for dose escalation in high-dose methotrexate therapy.
• Predicted plasma concentrations aid in anticipating and managing potential methotrexate toxicity.
• The model assists physicians in determining appropriate rescue agent requirements based on predicted drug levels.