Untreated invasive aspergillosis results in high mortality rate in pediatric cancer patients. Voriconazole (VORI), the first line of treatment, requires strict dose monitoring because of its narrow therapeutic index and individual variation in plasma concentration levels. Commonly co-administered drugs; either Esomeprazole (ESO) or Ondansetron (OND) have reported drug-drug interaction with VORI that should adversely alter therapeutic outcomes of the latter. Although VORI, ESO and OND are co-administered to pediatric cancer patients, the combined effect of ESO and OND on the plasma concentration levels of VORI has not been fully explored. In this study, an accurate, reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed and validated for simultaneous determination of VORI, ESO, and OND in ultra-low sample volumes (25 μL) of plasma of pediatric cancer patients. Based on the physicochemical properties of the studied drugs and internal standard, liquid-liquid extraction was successfully adopted with methyl t-butyl ether. Consistent and reproducible recovery of the three drugs and the internal standard were calculated using plasma and matrix matched samples (RE% > 72.97%, RSD < 8.29%). Chromatographic separation was carried out using UPLC with C18 column and a mobile phase of acetonitrile:water:methanol (70:25:5 V/V/V) at 0.3 mL/min. Mass spectrometric determination at positive electrospray ionization in the MRM mode was employed. The analysis was achieved within 4 min over a linear concentration range of 1.00–200.00 ng/mL for the three drugs. The assay validity was assessed as per the Food and Drug Administration guidelines for bioanalytical method validation, and satisfactory results were obtained. The accuracy and precision were within the acceptable limits for the three drugs in both quality control and incurred plasma samples. Matrix effect and process efficiency were investigated in neat solvent, post-extraction matrix, and plasma. Correlation of the plasma concentration levels of the three drugs revealed differences from the reported drug-drug interactions. This confirmed the need for simultaneous determination of VORI and co-administered drugs in order to achieve optimal therapeutic outcomes. To achieve this, analysis results of this study, genetic polymorphisms in CYP2C19 and clinical data will be used to establish one model incorporating all possible factors that might lead to variation in therapeutic outcomes.

未经治疗的侵袭性曲霉病会导致儿童癌症患者的高死亡率。治疗的第一线伏立康唑（VORI）由于其狭窄的治疗指数和血浆浓度水平的个体差异，需要严格的剂量监测。共同使用的药物；埃索美拉唑（ESO）或昂丹司琼（OND）均已报告与VORI发生药物相互作用，这将不利地改变后者的治疗效果。尽管将VORI，ESO和OND联合用于儿童癌症患者，但尚未充分探索ESO和OND对VORI血浆浓度水平的联合作用。在这项研究中，开发了一种准确，可靠且灵敏的液相色谱-串联质谱（LC-MS / MS）分析方法，并验证了该方法可同时测定VORI，ESO，和超低剂量（25μL）的小儿癌症患者血浆中的OND。根据所研究药物的理化性质和内标，成功地采用了甲基叔丁基醚进行液-液萃取。使用血浆和基质匹配的样品（RE％> 72.97％，RSD <8.29％）计算出三种药物和内标物的一致且可重复的回收率。使用带C18色谱柱的UPLC和以0.3 mL / min的乙腈：水：甲醇（70：25：5 V / V / V）流动相进行色谱分离。在MRM模式下采用正电喷雾电离质谱法进行测定。三种药物的线性浓度范围为1.00–200.00 ng / mL，在4分钟内完成了分析。根据食品和药物管理局的生物分析方法验证指南评估了测定的有效性，并获得了满意的结果。在质量控制和实际血浆样品中，这三种药物的准确性和精密度均在可接受的范围内。在纯溶剂，萃取后基质和血浆中研究了基质效应和工艺效率。三种药物的血浆浓度水平的相关性揭示了与已报道的药物-药物相互作用的差异。这证实了需要同时测定VORI和共同给药的药物，以达到最佳治疗效果。为此，本研究的分析结果