We studied MTX plasma pharmacokinetics in 102 occasions of high dose (200-350mg/kg) infusion for 6 hours followed by CV factor rescue for 15 cases with osteosarcoma and 1 case with chondrosarcoma. Serum MTX concentrations were measured at 0-hour, 24-hour, 48-hour and 72-hour after MTX infusion was terminated.
We investigated several factors determining the terminal level of serum MTX. And using the two compartment models of pharmacokinetic theory, we tried to simulate the clearance curve of serum MTX. Only these analyses could predict the conditions of rescue and evaluate the effectiveness of this therapy for each case accurately.
