University of Cologne, Faculty of Medicine and University Hospital Cologne, Center for Pharmacology, Department I of Pharmacology, Cologne, Germany.
PortaCellTec Biosciences GmbH, Göttingen, Germany.
Eur J Pharm Sci. 2023 Jul 1;186:106459. doi: 10.1016/j.ejps.2023.106459. Epub 2023 May 3.
Cocktails of transporter probe drugs are used in vivo to assess transporter activity and respective drug-drug interactions. An inhibitory effect of components on transporter activities should be ruled out. Here, for a clinically tested cocktail consisting of adefovir, digoxin, metformin, sitagliptin, and pitavastatin, inhibition of major transporters by individual probe substrates was investigated in vitro.
Transporter transfected HEK293 cells were used in all evaluations. Cell-based assays were applied for uptake by human organic cation transporters 1/2 (hOCT1/2), organic anion transporters 1/3 (hOAT1/3), multidrug and toxin extrusion proteins 1/2K (hMATE1/2K), and organic anion transporter polypeptide 1B1/3 (hOATP1B1/3). For P-glycoprotein (hMDR1) a cell-based efflux assay was used whereas an inside-out vesicle-based assay was used for the bile salt export pump (hBSEP). All assays used standard substrates and established inhibitors (as positive controls). Inhibition experiments using clinically achievable concentrations of potential perpetrators at the relevant transporter expression site were carried out initially. If there was a significant effect, the inhibition potency (K) was studied in detail.
In the inhibition tests, only sitagliptin had an effect and reduced hOCT1- and hOCT2- mediated metformin uptake and hMATE2K mediated MPP uptake by more than 70%, 80%, and 30%, respectively. The ratios of unbound C (observed clinically) to K of sitagliptin were low with 0.009, 0.03, and 0.001 for hOCT1, hOCT2, and hMATE2K, respectively.
The inhibition of hOCT2 in vitro by sitagliptin is in agreement with the borderline inhibition of renal metformin elimination observed clinically, supporting a dose reduction of sitagliptin in the cocktail.
转运体探针药物的鸡尾酒在体内用于评估转运体活性和相应的药物相互作用。应排除成分对转运体活性的抑制作用。在这里，我们研究了一种临床测试的鸡尾酒，由阿德福韦、地高辛、二甲双胍、西他列汀和匹伐他汀组成，用个体探针底物研究了其对主要转运体的抑制作用。
所有评估均使用转染了人有机阳离子转运体 1/2（hOCT1/2）、有机阴离子转运体 1/3（hOAT1/3）、多药和毒素外排蛋白 1/2K（hMATE1/2K）和有机阴离子转运多肽 1B1/3（hOATP1B1/3）的人源 HEK293 细胞进行细胞基础测定。对于 P-糖蛋白（hMDR1），使用基于细胞的外排测定法，而对于胆盐输出泵（hBSEP），则使用外翻囊泡法。所有测定均使用标准底物和已建立的抑制剂（阳性对照）。最初在相关转运体表达部位使用临床可行浓度的潜在肇事者进行抑制实验。如果有显著效果，则详细研究抑制效力（K）。
在抑制试验中，只有西他列汀具有作用，并且减少了 hOCT1 和 hOCT2 介导的二甲双胍摄取，以及 hMATE2K 介导的 MPP 摄取，分别超过 70%、80%和 30%。西他列汀与 hOCT1、hOCT2 和 hMATE2K 的未结合 C（临床观察到）与 K 的比值分别为 0.009、0.03 和 0.001。
西他列汀在体外对 hOCT2 的抑制作用与临床观察到的肾脏二甲双胍清除率的边缘抑制作用一致，支持在鸡尾酒中减少西他列汀的剂量。
