The anticancer drug etoposide is associated with leukemias with MLL gene translocations and other translocations as a treatment complication. The genotype of cytochrome P450 3A4 (CYP3A4), which converts etoposide to its catechol metabolite, influences the risk. In order to perform pharmacokinetic studies aimed at further elucidation of the translocation mechanism, we have developed and validated a liquid chromatography/electrospray/tandem mass spectrometry assay for the simultaneous analysis of etoposide and its catechol metabolite in human plasma. The etoposide analog teniposide was used as the internal standard. Liquid chromatography was performed on a YMC ODS-AQ column. Simultaneous determination of etoposide and its catechol metabolite was achieved using a small volume of plasma, so that the method is suitable for pediatric patients. The limits of detection were 200 ng ml−1 etoposide and 10 ng ml−1 catechol metabolite in human plasma and 25 ng ml−1 etoposide and 2.5 ng ml−1 catechol metabolite in protein-free plasma, respectively. Acceptable precision and accuracy were obtained for concentrations in the calibration curve ranges 0.2–100 µg ml−1 etoposide and 10–5000 ng ml−1 catechol metabolite in human plasma. Acceptable precision and accuracy for protein-free human plasma in the range 25–15 000 ng ml−1 etoposide and 2.5–1500 ng ml−1 etoposide catechol were also achieved. This method was selective and sensitive enough for the simultaneous quantitation of etoposide and its catechol as a total and protein-free fraction in small plasma volumes from pediatric cancer patients receiving etoposide chemotherapy. A pharmacokinetic model has been developed for future studies in large populations. Copyright © 2001 John Wiley & Sons, Ltd.
抗癌药物
依托泊苷(etoposide)作为一种治疗并发症,与带有 MLL
基因易位和其他易位的白血病有关。细胞色素 P450 3A4 (CYP3A4)可将
依托泊苷转化为
儿茶酚代谢物,其
基因型会影响这种风险。为了进行药代动力学研究,进一步阐明其转移机制,我们开发并验证了一种
液相色谱/电喷雾/串联质谱测定法,用于同时分析人体血浆中的
依托泊苷及其
儿茶酚代谢物。
依托泊苷类似物
替尼泊苷被用作内标。采用 YMC ODS-AQ 色谱柱进行
液相色谱分析。使用少量血浆即可同时测定
依托泊苷及其
儿茶酚代谢物,因此该方法适用于儿科患者。人体血浆中
依托泊苷和
儿茶酚代谢物的检出限分别为200 ng ml-1 和10 ng ml-1,无蛋白血浆中
依托泊苷和
儿茶酚代谢物的检出限分别为25 ng ml-1 和2.5 ng ml-1。人体血浆中
依托泊苷和
儿茶酚代谢物的校准曲线范围分别为 0.2-100 µg ml-1 和 10-5000 ng ml-1,精密度和准确度均可接受。在无蛋白质的人体血浆中,
依托泊苷和
儿茶酚代谢物的精密度和准确度分别为 25-15000 纳克 ml-1 和 2.5-1500 纳克 ml-1。该方法的选择性和灵敏度足以同时定量检测接受
依托泊苷化疗的小儿癌症患者血浆中
依托泊苷及其
邻苯二酚的总量和不含蛋白质的部分。我们还建立了一个药代动力学模型,以便将来在大量人群中进行研究。Copyright © 2001 John Wiley & Sons, Ltd. All Rights Reserved.