Dahmane Elyes, Boccard Julien, Csajka Chantal, Rudaz Serge, Décosterd Laurent, Genin Eric, Duretz Bénédicte, Bromirski Maciej, Zaman Khalil, Testa Bernard, Rochat Bertrand
School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, 1211, Geneva 4, Switzerland.
Anal Bioanal Chem. 2014 Apr;406(11):2627-40. doi: 10.1007/s00216-014-7682-2. Epub 2014 Mar 16.
Liquid-chromatography (LC) high-resolution (HR) mass spectrometry (MS) analysis can record HR full scans, a technique of detection that shows comparable selectivity and sensitivity to ion transitions (SRM) performed with triple-quadrupole (TQ)-MS but that allows de facto determination of "all" ions including drug metabolites. This could be of potential utility in in vivo drug metabolism and pharmacovigilance studies in order to have a more comprehensive insight in drug biotransformation profile differences in patients. This simultaneous quantitative and qualitative (Quan/Qual) approach has been tested with 20 patients chronically treated with tamoxifen (TAM). The absolute quantification of TAM and three metabolites in plasma was realized using HR- and TQ-MS and compared. The same LC-HR-MS analysis allowed the identification and relative quantification of 37 additional TAM metabolites. A number of new metabolites were detected in patients' plasma including metabolites identified as didemethyl-trihydroxy-TAM-glucoside and didemethyl-tetrahydroxy-TAM-glucoside conjugates corresponding to TAM with six and seven biotransformation steps, respectively. Multivariate analysis allowed relevant patterns of metabolites and ratios to be associated with TAM administration and CYP2D6 genotype. Two hydroxylated metabolites, α-OH-TAM and 4'-OH-TAM, were newly identified as putative CYP2D6 substrates. The relative quantification was precise (<20 %), and the semiquantitative estimation suggests that metabolite levels are non-negligible. Metabolites could play an important role in drug toxicity, but their impact on drug-related side effects has been partially neglected due to the tremendous effort needed with previous MS technologies. Using present HR-MS, this situation should evolve with the straightforward determination of drug metabolites, enlarging the possibilities in studying inter- and intra-patients drug metabolism variability and related effects.
液相色谱（LC）高分辨率（HR）质谱（MS）分析可记录HR全扫描，这是一种检测技术，其选择性和灵敏度与三重四极杆（TQ）-MS进行的离子跃迁（SRM）相当，但实际上能够测定“所有”离子，包括药物代谢物。这在体内药物代谢和药物警戒研究中可能具有潜在用途，以便更全面地了解患者药物生物转化谱的差异。这种同时进行定量和定性（定量/定性）的方法已在20例长期接受他莫昔芬（TAM）治疗的患者中进行了测试。使用HR-MS和TQ-MS实现了血浆中TAM及其三种代谢物的绝对定量，并进行了比较。相同的LC-HR-MS分析还可鉴定并相对定量另外37种TAM代谢物。在患者血浆中检测到了一些新的代谢物，包括分别对应于经过六个和七个生物转化步骤的TAM的去甲基三羟基-TAM-葡萄糖苷和去甲基四羟基-TAM-葡萄糖苷缀合物。多变量分析使代谢物和比率的相关模式与TAM给药和CYP2D6基因型相关联。两种羟基化代谢物α-OH-TAM和4'-OH-TAM被新鉴定为假定的CYP2D6底物。相对定量精确（<20%），半定量估计表明代谢物水平不可忽略。代谢物可能在药物毒性中起重要作用，但由于先前的质谱技术需要巨大努力，它们对药物相关副作用的影响在一定程度上被忽视了。使用当前的HR-MS，随着药物代谢物的直接测定，这种情况应该会有所改变，扩大了研究患者间和患者内药物代谢变异性及相关影响的可能性。
