Yang Le, Yan Chenyang, Zhang Feng, Jiang Bo, Gao Shouhong, Liang Youtian, Huang Lifeng, Chen Wansheng
Department of Pharmacy, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, P.R. China.
Department of Quality Management, Changzheng Hospital, Second Military Medical University, No. 415, Fengyang Road, Shanghai 200003, P.R. China.
Exp Anim. 2018 Feb 9;67(1):71-82. doi: 10.1538/expanim.17-0048. Epub 2017 Nov 13.
Cyclophosphamide (CP) is widely used in anticancer therapy regimens and 2-dechloroethylcyclophosphamide (DECP) is its side-chain dechloroethylated metabolite. N-dechloroethylation of CP mediated by the enzyme CYP3A4 yields nephrotoxic and neurotoxic chloroacetaldehyde (CAA) in equimolar amount to DECP. This study aimed to evaluate the inhibitory effect of ketoconazole (KTZ) on CP metabolism through in vitro and in vivo drug-drug interaction (DDI) research. Long-term treatment of KTZ induces hepatic injury; thus single doses of KTZ at low, middle, and high levels (10, 20, and 40 mg/kg) were investigated for pharmacokinetic DDI with CP. Our in vitro human liver microsome modeling approach suggested that KTZ inhibited CYP3A4 activity and then decreased DECP exposure. In addition, an UHPLC-MS/MS method for quantifying CP, DECP, and KTZ in rat plasma was developed and fully validated with a 4 min analysis coupled with a simple and reproducible one-step protein precipitation. A further in vivo pharmacokinetic study demonstrated that combination use of CP (10 mg/kg) and KTZ (10, 20, and 40 mg/kg) in rats caused a KTZ dose-dependent decrease in main parameters of DECP (C, T, and AUC) and provided magnitude exposure of DECP (more than a 50% AUC decrease) as a consequence of CYP3A inhibition but had only a small effect on the CP plasma concentration. Our results suggested that combination usage of a CYP3A4 inhibitor like KTZ may decrease CAA exposure and thus intervene against CAA-induced adverse effects in CP clinical treatment.
环磷酰胺（CP）广泛应用于抗癌治疗方案中，2-去氯乙基环磷酰胺（DECP）是其侧链去氯乙基化代谢产物。由细胞色素P450 3A4（CYP3A4）酶介导的CP的N-去氯乙基化产生与DECP等摩尔量的具有肾毒性和神经毒性的氯乙醛（CAA）。本研究旨在通过体外和体内药物-药物相互作用（DDI）研究评估酮康唑（KTZ）对CP代谢的抑制作用。长期使用KTZ会导致肝损伤；因此，研究了低、中、高剂量（10、20和40 mg/kg）的单次KTZ剂量与CP的药代动力学DDI。我们的体外人肝微粒体建模方法表明，KTZ抑制CYP3A4活性，进而降低DECP的暴露量。此外，开发了一种超高效液相色谱-串联质谱（UHPLC-MS/MS）方法来定量大鼠血浆中的CP、DECP和KTZ，并通过4分钟分析结合简单且可重复的一步蛋白沉淀法进行了全面验证。进一步的体内药代动力学研究表明，大鼠联合使用CP（10 mg/kg）和KTZ（10、20和40 mg/kg）会导致KTZ剂量依赖性地降低DECP的主要参数（C、T和AUC），并且由于CYP3A抑制导致DECP暴露量大幅降低（AUC降低超过50%），但对CP血浆浓度影响较小。我们的结果表明，联合使用像KTZ这样的CYP3A4抑制剂可能会降低CAA的暴露量，从而在CP临床治疗中干预CAA诱导的不良反应。
