Objective： To study the cerebrospinal fluid pharmacokinetics of intravenously administered high dose-methotrexate （HD-MTX） and provide a solid fundament for clinical practice. Methods： MTX at a high dose ranging f...Objective： To study the cerebrospinal fluid pharmacokinetics of intravenously administered high dose-methotrexate （HD-MTX） and provide a solid fundament for clinical practice. Methods： MTX at a high dose ranging from 1.0 to 3.0 g per course was intravenously administered to 30 patients with malignant tumors. Blood and CSF samples were consecutively collected up to 36 h after the initiation of infusion （6 h）. MTX concentrations were measured by using a reversed phase high-performance liquid chromatography （RP-HPLC） assay. Results： CSF MTX concentrations were （1.65±1.52）×10^-6, （4.3±3.34）× 10^-7, （1.46±1.10）×10^-7 and （3.19±4.38）×10^-8 mol/L, respectively, at 0, 6, 12 and 24 h post infusion, and became undetectable at 36 h post infusion. The concentration-time curve of CSF MTX closely resembled that of the plasma MTX and fitted with the following linear regression equation： Y=0.057 97＋0.010 82X （Y： CSF MTX concentration, X： Plasma MTX concentration, r=0.8357）. Conclusion： CSF MTX was metabolized in a linear two-compartment model. Additionally, pharmacokinetic analysis of MTX levels indicated a positive correlation between CSF MTX and plasma MTX levels.展开更多
文摘Objective： To study the cerebrospinal fluid pharmacokinetics of intravenously administered high dose-methotrexate （HD-MTX） and provide a solid fundament for clinical practice. Methods： MTX at a high dose ranging from 1.0 to 3.0 g per course was intravenously administered to 30 patients with malignant tumors. Blood and CSF samples were consecutively collected up to 36 h after the initiation of infusion （6 h）. MTX concentrations were measured by using a reversed phase high-performance liquid chromatography （RP-HPLC） assay. Results： CSF MTX concentrations were （1.65±1.52）×10^-6, （4.3±3.34）× 10^-7, （1.46±1.10）×10^-7 and （3.19±4.38）×10^-8 mol/L, respectively, at 0, 6, 12 and 24 h post infusion, and became undetectable at 36 h post infusion. The concentration-time curve of CSF MTX closely resembled that of the plasma MTX and fitted with the following linear regression equation： Y=0.057 97＋0.010 82X （Y： CSF MTX concentration, X： Plasma MTX concentration, r=0.8357）. Conclusion： CSF MTX was metabolized in a linear two-compartment model. Additionally, pharmacokinetic analysis of MTX levels indicated a positive correlation between CSF MTX and plasma MTX levels.
