Drug Metabolism and Disposition最新文献

{"title":"A 3-step static mechanistic modeling approach to predicting transporter- and enzyme-mediated interaction signals of direct oral anticoagulants.","authors":"Mostafa Ben Ahmed, Anne M Filppula, Aleksi Tornio","doi":"10.1016/j.dmd.2026.100360","DOIUrl":"10.1016/j.dmd.2026.100360","url":null,"abstract":"<p><p>Direct oral anticoagulants (DOACs) are susceptible to drug-drug interactions involving both transport and metabolism. The relative contribution of intestinal transporters in DOAC pharmacokinetics, however, is uncharacterized, hindering the prediction of their drug interactions. In this study, we examined potential interactions of select precipitants with apixaban, dabigatran, edoxaban, and rivaroxaban using a 3-step static mechanistic combinatorial modeling approach. In this approach, we (1) calculated apparent estimates of the fractions of efflux transport (f_e) of the 4 DOACs by the intestinal breast cancer resistance protein and intestinal permeability glycoprotein (P-gp), (2) validated our estimates, and (3) used them to simulate unstudied drug interactions with the anticoagulants. We estimated P-gp and breast cancer resistance protein transport to play a similar role in the interactions of apixaban and rivaroxaban (f_{e_P-gp} = 0.21, f_{e_breast cancer resistance protein} = 0.13). Additionally, the role of P-gp was prominent in the interactions affecting dabigatran etexilate (f_{e_P-gp} = 0.61) and less so in those affecting edoxaban (f_{e_P-gp} = 0.38). Using our apparent estimates, we predicted 144 interaction signals of 47 drugs with the 4 anticoagulants. All signals showed potential change >25% in the area under the curve of DOACs, warranting further investigation. Using our combined model, we were able to uncover new drug interaction signals, including previously unrecognized signals by kinase inhibitors. SIGNIFICANCE STATEMENT: Multiple enzymes and transporters affect direct oral anticoagulant pharmacokinetics. Drugs interacting with the same proteins may increase the levels of direct oral anticoagulants, leading to bleeding complications. Current methods predicting such interactions focus only on individual enzymes or transporters, limiting the prediction of cases where both may be involved. In this study, we combined multiple models to capture the complexity of interactions affecting direct oral anticoagulants. Using our validated model, we predicted 144 drug-drug interaction signals with potential clinical significance.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100360"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13688972/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148653254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial metabolite profiling identifies taurocholic acid as a protective mediator in hepatic ischemia-reperfusion injury: A mass spectrometry imaging and pharmacological study.","authors":"Chuang Du, Chu-Ting Xu, Qi Zhang, Lei Chen, Shan-Shan Zhao, Yi-Zhe Fan, Guang-Bo Ge, Zhan-You Wang, Hui-Xin Liu","doi":"10.1016/j.dmd.2026.100357","DOIUrl":"10.1016/j.dmd.2026.100357","url":null,"abstract":"<p><p>Hepatic ischemia-reperfusion injury (IRI) remains a major clinical obstacle during liver surgery and liver transplantation, and effective targeted intervention strategies are still limited. In the present study, we combined mass spectrometry imaging, in vitro cellular experiments, and in vivo animal tests to explore key functional metabolites involved in the progression of hepatic IRI. Spatial metabolite profiling via mass spectrometry imaging systematically mapped metabolic disturbances in liver tissues during IRI progression and confirmed that taurocholic acid (TCA) undergoes distinct spatial and temporal expression alterations in damaged liver regions. Subsequent pharmacological experiments verified that exogenous TCA intervention effectively alleviated hepatic IRI damage. TCA exerted prominent hepatoprotective functions, including antiapoptosis, anti-inflammation, antioxidation, and promotion of bile acid excretion. Mechanistically, TCA activated hepatic farnesoid X receptor signaling, which further suppressed excessive inflammatory responses, restrained abnormal de novo bile acid synthesis, and facilitated bile acid efflux, thereby restoring hepatic bile acid homeostasis and relieving liver injury. SIGNIFICANCE STATEMENT: This study identifies taurocholic acid (TCA) as an important protective mediator against hepatic ischemia-reperfusion injury. Our results demonstrate that mass spectrometry imaging-based spatial metabolite analysis is a powerful approach to discover functional injury-related metabolites, whereas TCA-mediated farnesoid X receptor activation provides a feasible therapeutic strategy for the prevention and treatment of hepatic ischemia-reperfusion injury.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100357"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148577311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Generation and characterization of a serum albumin-humanized mouse model and its utility for detection of albumin adduct formation in vivo.","authors":"Xiangmeng Wu, Weiguo Han, Lei Yin, Weizhu Yang, Jonathan Sheng, John Han, Robert J Turesky, Laura S Van Winkle, Qing-Yu Zhang, Xinxin Ding","doi":"10.1016/j.dmd.2026.100354","DOIUrl":"10.1016/j.dmd.2026.100354","url":null,"abstract":"<p><p>An albumin-humanized mouse model was generated via crossbreeding between albumin-transgenic and albumin-null mice and characterized. Immunoblot analyses confirmed that only human, but not mouse, albumin was expressed, and they revealed that the level of serum human albumin in the albumin-humanized mouse was 5-6 times the level in the albumin-transgenic mouse. Serum albumin levels (measured in plasma) were 3-4 times lower, whereas globulin levels were 2 times higher, in the albumin-humanized than in wild-type mice. The transgene integration site was localized via optical genome mapping to mouse chromosome 14, between 2 marker positions that are 143-kilobase pairs apart. A neighboring gene (alpha fetal protein) to albumin on the human chromosome was confirmed absent in the transgenic mouse. A transgene-mouse genome junction sequence was further identified, enabling a new protocol to distinguish between hemizygous and homozygous albumin-transgenic mice. Transgenic human albumin formed covalent adducts with naphthalene 1,2-oxide (NAO) ex vivo at the Cys³⁴ residue, which was recovered in the peptide ³¹LQQCPF³⁶ following tryptic/chymotryptic digestion. LQQC∗^[NAO]PF, structurally confirmed by mass spectral comparisons with synthetic adduct standards, was also detected in protease-digested plasma from homozygous albumin-humanized mice that were exposed to naphthalene through intraperitoneal injection (200 mg/kg) or inhalation (20 ppm). Pharmacokinetic analysis of plasma NAO-albumin, in comparison with NAO-glutathione, revealed a later time at maximal concentration (9.6 versus 2 hours), lower maximal concentration (0.21 versus 12 μM), and longer elimination half-life (79.7 versus 2.3 hours) for NAO-albumin following intraperitoneal naphthalene injection; the persistence of NAO-albumin adduct was also demonstrated following inhalation naphthalene exposures. SIGNIFICANCE STATEMENT: An albumin-humanized mouse was generated and characterized to demonstrate its utility for detecting in vivo formation of reactive metabolite adducts with human albumin. Key findings, including detection of the albumin adduct with naphthalene 1,2-oxide (NAO) at Cys³⁴ following exposure of mice to naphthalene, a ubiquitous pollutant and possible human carcinogen, and persistence of the NAO-albumin adduct in plasma relative to NAO-glutathione adducts, indicate that the model will be valuable for discovering biomarkers of exposure and potential toxicity for numerous drugs and other xenobiotics.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100354"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13682334/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148577341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanistically resolved prediction of compound hepatotoxicity using primary human liver spheroids-Application to recent real-world cases.","authors":"Yufeng Li, Hongda Sheng, Tingting Zhou, Chen Xing, Miriam Kukasch, Siyuan Shao, Sonia Youhanna, Sabine U Vorrink, Yingxin Liang, Anne T Nies, Julia Dressler, Charlotte Kölz, Jinhye Ryu, Nayere Taebnia, Dominik Jacob, Caroline Hauser, Carl Petersson, Kathrin Klein, Oliver Burk, Boxu Shi, Qiaojun He, Volker M Lauschke","doi":"10.1016/j.dmd.2026.100346","DOIUrl":"10.1016/j.dmd.2026.100346","url":null,"abstract":"<p><p>Drug-induced liver injury remains a major cause of clinical trial attrition and postmarketing drug withdrawals, reflecting persistent translational gaps in predictive preclinical models of compound hepatotoxicity. Here, we applied a well-characterized 3-dimensional primary human liver spheroid platform to interrogate diverse mechanisms of hepatotoxicity and benchmark performance against recent real-world clinical cases. After multicenter technology transfer, spheroids maintained stable hepatic functionality, including expression of metabolic enzymes and transporters, albumin secretion, and long-term CYP activity. Importantly, repeated-dose exposure to established hepatotoxins demonstrated robust, concentration-dependent toxicity with excellent interexperimental (R² = 0.98) and interdonor (R² = 0.89) reproducibility. To resolve toxicity mechanisms, we implemented Seahorse extracellular flux analysis in liver spheroids, which enabled sensitive detection of early mitochondrial dysfunction, allowing mechanistic discrimination between mitochondrial and nonmitochondrial toxins. Cholestatic liability was identified using bile acid coexposure with accurate classification of chlorpromazine and bosentan and confirmation of bile salt export pump downregulation. Importantly, the model also recapitulated hepatotoxicity signals observed in recent clinical development, including for Bruton's tyrosine kinase inhibitors (tolebrutinib and evobrutinib), oral glucagon-like peptide-1 receptor agonists (danuglipron vs orforglipron), synergistic toxicity on azelaprag-tirzepatide coexposure and enhanced sensitivity to the IL-17A inhibitor LY3509754 on coculture with nonparenchymal liver cells. Collectively, we present new assays for the mechanistic resolution of hepatotoxicity and provide further evidence that 3-dimensional human liver spheroids enable reproducible, mechanistically informative, and clinically aligned assessment of drug-induced liver injury across multiple modalities, which supports their application for preclinical de-risking of drug candidates. SIGNIFICANCE STATEMENT: This study shows that primary human liver spheroids provide a reproducible and mechanistically informative platform for preclinical assessments of drug metabolism and liver toxicity. The model maintains stable CYP expression and metabolic activity, captures the impact of nonparenchymal cells on hepatic clearance, and detects mitochondrial, cholestatic, and interaction-driven toxicity, including recent real-world clinical cases. These findings support 3-dimensional human liver spheroids as translational new approach methodologies for integrating metabolism and toxicity in drug development.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100346"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13688977/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148411109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of CYP3A5 and CYP3A4 in the metabolism and toxicity of 10-hydroxyl mesaconitine, a new potential toxicity marker of Radix Aconiti Lateralis Preparata (Fuzi), in vitro and in vivo.","authors":"Yu Fu, Yu Cai, Fangyuan Li, Tongyang Ma, Caiyan Wang, Rong Zhang, Zhongqiu Liu, Dongyan Bai, Qi Liang, Lijun Zhu","doi":"10.1016/j.dmd.2026.100352","DOIUrl":"10.1016/j.dmd.2026.100352","url":null,"abstract":"<p><p>10-Hydroxyl mesaconitine (10-OH MA) is a new potential toxicity marker of Radix Aconiti Lateralis Preparata (Fuzi), which is widely used for the treatment of cardiovascular diseases, rheumatoid arthritis, and other illnesses. Recently, we found that 10-OH MA concentrations in the plasma and urine of outpatients are comparable to those of aconitine, one of the most important toxicity markers of Fuzi. Published studies have shown that CYP3A plays important roles in the disposition and toxicity of Fuzi. This study aims to elucidate the role of cytochrome P450 enzymes in the metabolism and toxicity of 10-OH MA. 10-OH MA was transformed to 14 and 12 metabolites when incubated with human and mouse liver microsomes, respectively. The major metabolic pathways included hydroxylation, dehydrogenation, and demethylation. Human recombinant enzyme metabolic assays revealed that CYP3A5 was mainly involved in 10-OH MA metabolism, followed by CYP3A4, CYP3A7, CYP1A2, and CYP2C8. CYP3A inhibitor ketoconazole significantly inhibited the metabolism of 10-OH MA in vitro. The dose-normalized area under the plasma concentration-time curve from time 0 to t (AUC_0-t/Dose) and tissue 10-OH MA concentrations were significantly increased in Cyp3a-inhibited C57BL/6J mice administered with 10-OH MA, which was accompanied by a sharp decrease in the LD₅₀ value and enhanced cardiotoxicity and neurotoxicity. Moreover, diltiazem markedly increased the AUC_0-t/Dose of 10-OH MA by 17.6-fold. Additionally, 10-OH MA competitively inhibited CYP3A5 and CYP3A4 in vitro, with apparent K_i values of 5.0 and 13.6 μmol/L, respectively. In conclusion, CYP3A5 and CYP3A4 are the pivotal enzymes responsible for the metabolism and toxicity of 10-OH MA. Coexposure to 10-OH-MA and CYP3A inhibitors likely significantly increased 10-OH MA toxicity. SIGNIFICANCE STATEMENT: 10-Hydroxyl mesaconitine (10-OH MA) is a potential toxicity marker of Radix Aconiti Lateralis Preparata (Fuzi), the metabolism of which is predominantly mediated by CYP3A5 and CYP3A4. CYP3A inhibition markedly increases systemic exposure and cardiotoxicity/neurotoxicity of 10-OH MA. In addition, 10-OH MA competitively inhibits CYP3A, indicating the risks of coadministration with CYP3A inhibitors.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100352"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148454921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A comprehensive investigation into the effect of bisphenol A on the expression of drug-metabolizing enzymes: Consequences for endogenous metabolites and xenobiotic pharmacokinetics.","authors":"Ananthu Malaplakkal Raju, Kannan Shajkumar, Subhashree Subhasmita Biswal, Aiswarya Suresh, Shrutika Milind Wankhade, Anandhu Kunnath Shaji, Swapnil Jayant Dengale","doi":"10.1016/j.dmd.2026.100361","DOIUrl":"10.1016/j.dmd.2026.100361","url":null,"abstract":"<p><p>Bisphenol A, a known endocrine disruptor, is a pervasive environmental contaminant because of its widespread use in everyday consumer products. It has been linked to numerous health hazards and shown to modulate the drug-metabolizing enzymes. There is a significant disparity in reported results in the literature, chiefly because of a focus on mRNA expression or substrate activity assays rather than on protein expression. The present study uses mass spectrometry-based targeted proteomics to investigate modulation in the expression of drug-metabolizing enzymes following environmentally relevant exposure to bisphenol A in a rat model. Furthermore, the plasma levels of endogenous metabolites of cytochrome P450 (CYP) 1B1, the highest fold-modulated enzyme, were also monitored. The pharmacokinetics of diclofenac, a substrate of the CYP2C family and UDP-glucuronosyltransferase (UGT) 2B7, were also studied. We identified 9 significantly altered proteins in hepatic drug metabolism, with 4 upregulated (CYP1B1, CYP1A2, UGT2B7, and UGT1A3) and 5 downregulated (CYP2A3, CYP2C13, CYP4A2, and UGT2B1). The upregulation of CYP1B1 leads to increased levels of endogenous metabolites, including retinoic acid and 4-hydroxyestradiol, which are teratogenic and procarcinogenic, respectively. The upregulation of UGT2B7 led to increased exposure to the acyl-glucuronide metabolite of diclofenac, which is known to cause hepatotoxicity, intestinal ulceration, and nephrotoxicity. SIGNIFICANCE STATEMENT: This study uses a mass spectrometry-based targeted proteomics approach to monitor all relevant drug-metabolizing enzymes (DMEs) after exposure to bisphenol A in a rat model. The study presents protein-level data of relevant DMEs and identified 9 significantly altered DMEs in hepatic drug metabolism. The modulation of DMEs is reflected in alterations in numerous endogenous metabolite levels with plausible adverse consequences. Further, the pharmacokinetics of substrate xenobiotic modulated by these enzymes is also altered.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100361"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148629740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytochrome P450 3A-mediated metabolic activation of fibleucin from Tinospora sagittata initiates liver injury in mice.","authors":"Jie Dai, Yufen Liao, Xueqian Cheng, Qing Zhang, Tingmin Ye, Dandan Yang, Chunlei Zhang, Ying Peng, Weiwei Li, Jiang Zheng","doi":"10.1016/j.dmd.2026.100345","DOIUrl":"10.1016/j.dmd.2026.100345","url":null,"abstract":"<p><p>TINOSPORA: sagittata is a widely used medicinal herb whose safety has raised increasing concerns in recent years. Fibleucin (FBL), a furanoditerpenoid isolated from T sagittata, has not been systematically evaluated for its safety and toxicological mechanisms despite its presence as a major bioactive constituent in this medicinal plant. To address this toxicological knowledge gap, we comprehensively investigated the hepatotoxicity and/or metabolic activation of FBL in vivo (mice) and in vitro (mouse and human liver microsomal incubations as well as primary mouse hepatocytes). Oral administration of FBL (single intragastric dose) dose-dependently elevated serum alanine transaminase, aspartate transaminase, alkaline phosphatase, blood ammonia, and total bile acid levels in mice, accompanied by hepatocellular degeneration, necrosis, and inflammatory infiltration. Pretreatment with the cytochrome P450 3A inhibitor ketoconazole (100 mg/kg) markedly alleviated the liver injury induced by FBL. Liquid chromatography-tandem mass spectrometry analysis of mouse liver microsomal incubations and primary hepatocyte exposure (1.0-50 μM FBL) revealed that FBL was bioactivated to an electrophilic intermediate reactive to thiols and amines. Similar observation was obtained in human liver microsomal incubations. The reactive intermediate was found to react with nucleophilic sites of hepatic glutathione and proteins to form the corresponding conjugates and adducts. The observed adduction correlated with the liver injury and cytotoxicity induced by FBL. Chemical synthesis was carried out to probe the mechanism of toxic action. The mechanistic investigation suggests that FBL was metabolized to the corresponding cis-2-butene-1,4-dial intermediate responsible for the glutathione depletion and protein adduction. SIGNIFICANCE STATEMENT: Tinospora sagittata is widely used, however, its hepatotoxic principles remain undefined. This study identifies fibleucin as a previously unrecognized hepatotoxic constituent and demonstrates that it undergoes cytochrome P450 3A-mediated metabolic activation to generate a reactive intermediate consistent with cis-2-butene-1,4-dial, leading to glutathione depletion and hepatic protein adduction. These findings establish a mechanistic link between bioactivation of a herbal constituent and liver injury, highlighting metabolic risk in furanoditerpenoid-containing traditional medicines.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100345"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148469614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiologically based pharmacokinetic modeling of the unusual kinetics of ketoconazole due to nonlinear liver binding and metabolism in rats.","authors":"Hee Eun Kang, Keumhan Noh, Jianfeng Huang, Liangliang Xu, Yanfen Teng, Lilly Xu, K Sandy Pang","doi":"10.1016/j.dmd.2026.100355","DOIUrl":"10.1016/j.dmd.2026.100355","url":null,"abstract":"<p><p>Ketoconazole (KTZ) is a well known inhibitor of intestinal and liver CYP3A4/5, and its kinetics is being re-evaluated in rats. In vitro binding and microsomal incubation studies confirmed saturable liver binding and metabolism and linear plasma binding of KTZ. These binding constants led to a decreasing trend of the liver tissue to blood partitioning ratio with increasing KTZ blood/plasma concentration. KTZ, assayed by liquid chromatography-tandem mass spectrometry, from single intravenous (2.5, 5, and 10 mg/kg) and oral (10, 20, and 40 mg/kg in 1% methylcellulose via gavage) doses displayed primarily nonlinear liver but negligible intestinal metabolism and low renal and biliary clearances. Improved fits to the KTZ blood and liver concentrations in physiologically based pharmacokinetic modeling were obtained upon upgrading the in vitro K_m,L and V_max,L for liver metabolism and the plasma binding constant, ѱ (ratio of plasma bound/unbound concentrations). However, minor improvement resulted upon fitting parameters for the intestinal metabolic intrinsic clearance and liver binding capacity and dissociation constant. The absorption rate constant, k_a, obtained from the combined intravenous and oral fits and sequential fitting of the intravenous then with oral data, was similar. The optimized model, which described KTZ nonlinear liver binding and metabolism, predicted the intravenous and oral data (area under the curve) well. Simulations were further conducted under nonlinear and linear conditions based on the segregated intestinal flow model (with 10% flow to enterocyte and 90% to serosal regions) and the traditional model to illustrate the roles of intestine versus liver controlling the extent of first-pass metabolism of drugs. SIGNIFICANCE STATEMENT: The complexity of nonlinear liver tissue binding, metabolism, and solubility issues toward ketoconazole was demonstrated in stepwise fitting of blood and liver data in physiologically based pharmacokinetic modeling to remove bias and errors. The optimized model, predicated on predominanat liver and minor intestinal metabolism, predicted the blood and liver ketoconazole area under the curve well. Simulations suggest a greater presystemic fractional intestinal metabolism for drugs given orally according to the segregated intestinal flow model (10% to enterocyte region) over the traditional model.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100355"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13689508/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148561042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A protein standard addition framework for absolute quantification of drug metabolizing enzymes.","authors":"Xiaofeng Wu, Sam Zhang, R Scott Obach, Qianying Yuan, Kimberly Lapham, Yuanyuan Shi, Lloyd Wei Tat Tang","doi":"10.1016/j.dmd.2026.100347","DOIUrl":"10.1016/j.dmd.2026.100347","url":null,"abstract":"<p><p>Accurate quantification of absorption, distribution, metabolism and elimination (ADME) proteins in complex human-derived matrices remains technically challenging. Although targeted bottom-up proteomic approaches have improved specificity and sensitivity relative to immunometric methods, peptide level absolute quantification (AQUA) remains confounded by peptide-dependent proteolytic recovery, limiting confidence in protein abundance estimates. Here, we describe AQUA-ADME, a protein level absolute quantification strategy that integrates protein standard addition with our previously described FAst Surfactant-Treated -enabled liquid chromatography-multiple reaction monitoring workflow to address peptide-dependent digestion bias. By spiking known amounts of purified recombinant human CYP3A4 into native human intestinal and hepatic microsomes prior to digestion, AQUA-ADME enforces matched proteolytic behavior between endogenous CYP3A4 and exogenously spiked recombinant human CYP3A4 within the same biological matrix, while stable isotope-labeled peptides correct for ionization variability. Using 4 structurally and spatially distinct CYP3A4 tryptic peptides, AQUA-ADME yielded highly concordant CYP3A4 abundance estimates within each microsomal pool (<2-fold variation across peptides), in contrast to the wide variability observed using conventional peptide-centric AQUA workflows. Normalization of microsomal CYP3A4-mediated midazolam 1'-hydroxylation and testosterone 6β-hydroxylation rates to AQUA-ADME-derived protein abundance collapsed apparent differences in turnover numbers and specificity constants between intestinal and hepatic microsomes, supporting enzyme abundance as the dominant driver of tissue-specific metabolic capacity. Collectively, these findings demonstrate that AQUA-ADME provides a simple, accessible, and mechanistically grounded approach for absolute protein quantification, strengthening the quantitative foundation for in vitro-in vivo extrapolation and physiologically based pharmacokinetic modeling. SIGNIFICANCE STATEMENT: Reliable absolute proteomic quantification is essential for confident interpretation of enzyme-normalized kinetic parameters and translational pharmacokinetic modeling. This study introduces AQUA-ADME, a protein standard addition approach that addresses peptide-dependent digestion bias inherent to peptide-centric proteomics. By enforcing matched digestion between endogenous and reference protein, AQUA-ADME yields coherent, protein level abundance estimates and improves confidence in derived turnover numbers. AQUA-ADME provides a mechanistically grounded framework to strengthen quantitative ADME analyses supporting in vitro-in vivo extrapolation and physiologically based pharmacokinetic applications.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100347"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148469568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiologically based pharmacokinetic framework for predicting CYP3A4-mediated drug-drug interactions of quetiapine with ketoconazole and carbamazepine.","authors":"Ji-Hun Jang, Seung-Hyun Jeong","doi":"10.1016/j.dmd.2026.100356","DOIUrl":"10.1016/j.dmd.2026.100356","url":null,"abstract":"<p><p>Quetiapine is primarily metabolized by CYP3A4, and its coadministration with potent CYP3A4 inhibitors (eg, ketoconazole) or inducers (eg, carbamazepine) may substantially alter systemic and central nervous system exposure. Although clinical evidence supports these interactions, quantitative predictions of plasma and brain interstitial concentrations remain limited. This study aimed to develop an integrated physiologically based pharmacokinetic (PBPK) model to quantitatively predict drug-drug interactions (DDIs) among quetiapine, ketoconazole, and carbamazepine, and to propose model-based dose-adjustment strategies to mitigate exposure-related risks. Previously validated PBPK models for quetiapine, ketoconazole, and carbamazepine were incorporated. Clinical DDI data from previous reports were digitized for model calibration, and parameters related to CYP3A4 inhibition and induction were optimized. Model qualification included visual predictive checks, residual analysis, and fold-error evaluation. The final model simulated multiple DDI scenarios, including concurrent and sequential coadministration, and explored dose-adjustment strategies for all 3 drugs. The PBPK model accurately reproduced observed quetiapine-ketoconazole and quetiapine-carbamazepine interaction profiles in both plasma and brain. Ketoconazole coadministration markedly increased quetiapine exposure (approximately 6-fold to 8-fold), whereas carbamazepine reduced exposure by approximately 4-fold to 6-fold. Concurrent or sequential triple-drug combinations induced substantial quetiapine fluctuations, indicating potential clinical instability. Dose-adjustment simulations suggested that quetiapine reduction (eg, 200 mg daily) partially mitigates ketoconazole-mediated overexposure, whereas even high quetiapine doses could not fully compensate for carbamazepine-induced underexposure. This model provides a robust quantitative framework for predicting quetiapine exposure under clinically relevant DDI scenarios and highlights the substantial risks associated with coadministration of potent CYP3A4 modulators. SIGNIFICANCE STATEMENT: Physiologically based pharmacokinetic modeling was used to quantitatively predict CYP3A4-mediated drug-drug interactions of quetiapine with ketoconazole and carbamazepine, integrating both systemic and brain interstitial exposure. The model reveals how strong CYP3A4 inhibition or induction markedly alters quetiapine exposure and provides a mechanistic framework to evaluate clinically relevant drug-drug interaction scenarios and guide evidence-based dose-adjustment strategies in psychotropic polypharmacy.</p>","PeriodicalId":11309,"journal":{"name":"Drug Metabolism and Disposition","volume":"54 8","pages":"100356"},"PeriodicalIF":3.6,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148600342","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}