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Britz H, Hanke N, Taub ME, Wang T, Prasad B, Fernandez É, Stopfer P, Nock V, Lehr T. Physiologically Based Pharmacokinetic Models of Probenecid and Furosemide to Predict Transporter Mediated Drug-Drug Interactions. Pharm Res 2020; 37:250. [PMID: 33237382 PMCID: PMC7688195 DOI: 10.1007/s11095-020-02964-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022]
Abstract
Purpose To provide whole-body physiologically based pharmacokinetic (PBPK) models of the potent clinical organic anion transporter (OAT) inhibitor probenecid and the clinical OAT victim drug furosemide for their application in transporter-based drug-drug interaction (DDI) modeling. Methods PBPK models of probenecid and furosemide were developed in PK-Sim®. Drug-dependent parameters and plasma concentration-time profiles following intravenous and oral probenecid and furosemide administration were gathered from literature and used for model development. For model evaluation, plasma concentration-time profiles, areas under the plasma concentration–time curve (AUC) and peak plasma concentrations (Cmax) were predicted and compared to observed data. In addition, the models were applied to predict the outcome of clinical DDI studies. Results The developed models accurately describe the reported plasma concentrations of 27 clinical probenecid studies and of 42 studies using furosemide. Furthermore, application of these models to predict the probenecid-furosemide and probenecid-rifampicin DDIs demonstrates their good performance, with 6/7 of the predicted DDI AUC ratios and 4/5 of the predicted DDI Cmax ratios within 1.25-fold of the observed values, and all predicted DDI AUC and Cmax ratios within 2.0-fold. Conclusions Whole-body PBPK models of probenecid and furosemide were built and evaluated, providing useful tools to support the investigation of transporter mediated DDIs. Supplementary Information The online version contains supplementary material available at 10.1007/s11095-020-02964-z.
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Affiliation(s)
- Hannah Britz
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany
| | - Nina Hanke
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany
| | - Mitchell E Taub
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut, USA
| | - Ting Wang
- Drug Metabolism and Pharmacokinetics, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut, USA
| | - Bhagwat Prasad
- Department of Pharmaceutical Sciences, Washington State University, Spokane, Washington, USA
| | - Éric Fernandez
- Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Peter Stopfer
- Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Valerie Nock
- Translational Medicine and Clinical Pharmacology, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Thorsten Lehr
- Clinical Pharmacy, Saarland University, Campus C2 2, 66123, Saarbrücken, Germany.
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Kesharwani SS, Kaur S, Tummala H, Sangamwar AT. Overcoming multiple drug resistance in cancer using polymeric micelles. Expert Opin Drug Deliv 2018; 15:1127-1142. [DOI: 10.1080/17425247.2018.1537261] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Siddharth S. Kesharwani
- Department of Pharmaceutical Sciences, College of Pharmacy & Allied Health Professions, South Dakota State University, Brookings, USA
| | - Shamandeep Kaur
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Mohali, India
| | - Hemachand Tummala
- Department of Pharmaceutical Sciences, College of Pharmacy & Allied Health Professions, South Dakota State University, Brookings, USA
| | - Abhay T. Sangamwar
- Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Mohali, India
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Scotcher D, Jones C, Rostami-Hodjegan A, Galetin A. Novel minimal physiologically-based model for the prediction of passive tubular reabsorption and renal excretion clearance. Eur J Pharm Sci 2016; 94:59-71. [PMID: 27033147 PMCID: PMC5074076 DOI: 10.1016/j.ejps.2016.03.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/02/2016] [Accepted: 03/22/2016] [Indexed: 01/08/2023]
Abstract
PURPOSE Develop a minimal mechanistic model based on in vitro-in vivo extrapolation (IVIVE) principles to predict extent of passive tubular reabsorption. Assess the ability of the model developed to predict extent of passive tubular reabsorption (Freab) and renal excretion clearance (CLR) from in vitro permeability data and tubular physiological parameters. METHODS Model system parameters were informed by physiological data collated following extensive literature analysis. A database of clinical CLR was collated for 157 drugs. A subset of 45 drugs was selected for model validation; for those, Caco-2 permeability (Papp) data were measured under pH6.5-7.4 gradient conditions and used to predict Freab and subsequently CLR. An empirical calibration approach was proposed to account for the effect of inter-assay/laboratory variation in Papp on the IVIVE of Freab. RESULTS The 5-compartmental model accounted for regional differences in tubular surface area and flow rates and successfully predicted the extent of tubular reabsorption of 45 drugs for which filtration and reabsorption were contributing to renal excretion. Subsequently, predicted CLR was within 3-fold of the observed values for 87% of drugs in this dataset, with an overall gmfe of 1.96. Consideration of the empirical calibration method improved overall prediction of CLR (gmfe=1.73 for 34 drugs in the internal validation dataset), in particular for basic drugs and drugs with low extent of tubular reabsorption. CONCLUSIONS The novel 5-compartment model represents an important addition to the IVIVE toolbox for physiologically-based prediction of renal tubular reabsorption and CLR. Physiological basis of the model proposed allows its application in future mechanistic kidney models in preclinical species and human.
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Affiliation(s)
- Daniel Scotcher
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom
| | | | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom; Simcyp Limited (a Certara Company), Sheffield, United Kingdom
| | - Aleksandra Galetin
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Manchester, United Kingdom.
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Scotcher D, Jones C, Posada M, Galetin A, Rostami-Hodjegan A. Key to Opening Kidney for In Vitro-In Vivo Extrapolation Entrance in Health and Disease: Part II: Mechanistic Models and In Vitro-In Vivo Extrapolation. AAPS JOURNAL 2016; 18:1082-1094. [PMID: 27506526 DOI: 10.1208/s12248-016-9959-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 07/11/2016] [Indexed: 12/11/2022]
Abstract
It is envisaged that application of mechanistic models will improve prediction of changes in renal disposition due to drug-drug interactions, genetic polymorphism in enzymes and transporters and/or renal impairment. However, developing and validating mechanistic kidney models is challenging due to the number of processes that may occur (filtration, secretion, reabsorption and metabolism) in this complex organ. Prediction of human renal drug disposition from preclinical species may be hampered by species differences in the expression and activity of drug metabolising enzymes and transporters. A proposed solution is bottom-up prediction of pharmacokinetic parameters based on in vitro-in vivo extrapolation (IVIVE), mediated by recent advances in in vitro experimental techniques and application of relevant scaling factors. This review is a follow-up to the Part I of the report from the 2015 AAPS Annual Meeting and Exhibition (Orlando, FL; 25th-29th October 2015) which focuses on IVIVE and mechanistic prediction of renal drug disposition. It describes the various mechanistic kidney models that may be used to investigate renal drug disposition. Particular attention is given to efforts that have attempted to incorporate elements of IVIVE. In addition, the use of mechanistic models in prediction of renal drug-drug interactions and potential for application in determining suitable adjustment of dose in kidney disease are discussed. The need for suitable clinical pharmacokinetics data for the purposes of delineating mechanistic aspects of kidney models in various scenarios is highlighted.
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Affiliation(s)
- Daniel Scotcher
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT, UK
| | - Christopher Jones
- DMPK, Oncology iMed, AstraZeneca R&D Alderley Park, Macclesfield, Cheshire, UK
| | - Maria Posada
- Drug Disposition, Lilly Research Laboratories, Indianapolis, Indiana, 46203, USA
| | - Aleksandra Galetin
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT, UK
| | - Amin Rostami-Hodjegan
- Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, University of Manchester, Stopford Building, Oxford Road, Manchester, M13 9PT, UK. .,Simcyp Limited (a Certara Company), Blades Enterprise Centre, Sheffield, UK.
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Alfarouk KO, Stock CM, Taylor S, Walsh M, Muddathir AK, Verduzco D, Bashir AHH, Mohammed OY, Elhassan GO, Harguindey S, Reshkin SJ, Ibrahim ME, Rauch C. Resistance to cancer chemotherapy: failure in drug response from ADME to P-gp. Cancer Cell Int 2015; 15:71. [PMID: 26180516 PMCID: PMC4502609 DOI: 10.1186/s12935-015-0221-1] [Citation(s) in RCA: 369] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/30/2015] [Indexed: 12/15/2022] Open
Abstract
Cancer chemotherapy resistance (MDR) is the innate and/or acquired ability of cancer cells to evade the effects of chemotherapeutics and is one of the most pressing major dilemmas in cancer therapy. Chemotherapy resistance can arise due to several host or tumor-related factors. However, most current research is focused on tumor-specific factors and specifically genes that handle expression of pumps that efflux accumulated drugs inside malignantly transformed types of cells. In this work, we suggest a wider and alternative perspective that sets the stage for a future platform in modifying drug resistance with respect to the treatment of cancer.
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Affiliation(s)
- Khalid O Alfarouk
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Sophie Taylor
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | - Megan Walsh
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
| | | | | | - Adil H H Bashir
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | | | - Gamal O Elhassan
- Uneizah Pharmacy College, Qassim University, AL-Qassim, Kingdom of Saudi Arabia ; Faculty of Pharmacy, Omdurman Islamic University, Khartoum, Sudan
| | | | - Stephan J Reshkin
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | | | - Cyril Rauch
- School of Veterinary Medicine and Science, University of Nottingham, Nottingham, UK
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Zhou S, Chan E, Duan W, Huang M, Chen YZ. Drug bioactivation, covalent binding to target proteins and toxicity relevance. Drug Metab Rev 2005; 37:41-213. [PMID: 15747500 DOI: 10.1081/dmr-200028812] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A number of therapeutic drugs with different structures and mechanisms of action have been reported to undergo metabolic activation by Phase I or Phase II drug-metabolizing enzymes. The bioactivation gives rise to reactive metabolites/intermediates, which readily confer covalent binding to various target proteins by nucleophilic substitution and/or Schiff's base mechanism. These drugs include analgesics (e.g., acetaminophen), antibacterial agents (e.g., sulfonamides and macrolide antibiotics), anticancer drugs (e.g., irinotecan), antiepileptic drugs (e.g., carbamazepine), anti-HIV agents (e.g., ritonavir), antipsychotics (e.g., clozapine), cardiovascular drugs (e.g., procainamide and hydralazine), immunosupressants (e.g., cyclosporine A), inhalational anesthetics (e.g., halothane), nonsteroidal anti-inflammatory drugs (NSAIDSs) (e.g., diclofenac), and steroids and their receptor modulators (e.g., estrogens and tamoxifen). Some herbal and dietary constituents are also bioactivated to reactive metabolites capable of binding covalently and inactivating cytochrome P450s (CYPs). A number of important target proteins of drugs have been identified by mass spectrometric techniques and proteomic approaches. The covalent binding and formation of drug-protein adducts are generally considered to be related to drug toxicity, and selective protein covalent binding by drug metabolites may lead to selective organ toxicity. However, the mechanisms involved in the protein adduct-induced toxicity are largely undefined, although it has been suggested that drug-protein adducts may cause toxicity either through impairing physiological functions of the modified proteins or through immune-mediated mechanisms. In addition, mechanism-based inhibition of CYPs may result in toxic drug-drug interactions. The clinical consequences of drug bioactivation and covalent binding to proteins are unpredictable, depending on many factors that are associated with the administered drugs and patients. Further studies using proteomic and genomic approaches with high throughput capacity are needed to identify the protein targets of reactive drug metabolites, and to elucidate the structure-activity relationships of drug's covalent binding to proteins and their clinical outcomes.
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Affiliation(s)
- Shufeng Zhou
- Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore.
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Uchaipichat V, Mackenzie PI, Guo XH, Gardner-Stephen D, Galetin A, Houston JB, Miners JO. HUMAN UDP-GLUCURONOSYLTRANSFERASES: ISOFORM SELECTIVITY AND KINETICS OF 4-METHYLUMBELLIFERONE AND 1-NAPHTHOL GLUCURONIDATION, EFFECTS OF ORGANIC SOLVENTS, AND INHIBITION BY DICLOFENAC AND PROBENECID. Drug Metab Dispos 2004; 32:413-23. [PMID: 15039294 DOI: 10.1124/dmd.32.4.413] [Citation(s) in RCA: 286] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The glucuronidation kinetics of the prototypic substrates 4-methylumbelliferone (4MU) and 1-naphthol (1NP) by human UDP-glucuronosyltransferases (UGT) 1A1, 1A3, 1A4, 1A6, 1A7, 1A8, 1A9, 1A10, 2B7, 2B15, and 2B17 were investigated. Where activity was demonstrated, inhibitory effects of diclofenac, probenecid, and the solvents acetone, acetonitrile, dimethyl sulfoxide, ethanol, and methanol were characterized. All isoforms except UGT1A4 glucuronidated 4MU, whereas all but UGT 1A4, 2B15, and 2B17 metabolized 1NP. However, kinetic models varied with substrate (for the same isoform) and from isoform to isoform (with the same substrate). Hyperbolic (Michaelis-Menten), substrate inhibition, and sigmoidal kinetics were variably observed for both 4MU and 1NP glucuronidation by the various UGTs. K(m) or S(50) (sigmoidal kinetics) and V(max) values varied 525- (8-4204 microM) and 1386-fold, respectively, for 4MU glucuronidation, and 1360- (1.3-1768 microM) and 37-fold, respectively, for 1NP glucuronidation. The use of a two-site model proved useful for those reactions exhibiting non-Michaelis-Menten glucuronidation kinetics. The organic solvents generally had a relatively minor effect on UGT isoform activity. UGT 2B15 and 2B17 were most susceptible to the presence of solvent, although solvent-selective inhibition was occasionally observed with other isoforms. Diclofenac and probenecid inhibited all isoforms, precluding the use of these compounds for the reaction phenotyping of xenobiotic glucuronidation pathways in human tissues. Diclofenac and probenecid K(i) values, determined for selected isoforms, ranged from 11 to 52 microM and 96 to 2452 microM, respectively. Overall, the results emphasize the need for the careful design and interpretation of kinetic and inhibition studies with human UGTs.
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Affiliation(s)
- Verawan Uchaipichat
- Department of Clinical Pharmacology, Flinders Medical Centre, Bedford Park, SA 5042, Australia.
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Shipkova M, Armstrong VW, Oellerich M, Wieland E. Acyl glucuronide drug metabolites: toxicological and analytical implications. Ther Drug Monit 2003; 25:1-16. [PMID: 12548138 DOI: 10.1097/00007691-200302000-00001] [Citation(s) in RCA: 191] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Although glucuronidation is generally considered a detoxification route of drug metabolism, the chemical reactivity of acyl glucuronides has been linked with the toxic properties of drugs that contain carboxylic acid moieties. It is now well documented that such metabolites can reach appreciable concentrations in blood. Furthermore, they are labile, undergo hydrolysis and pH-dependent intramolecular acyl migration to isomeric conjugates of glucuronic acid, and may react irreversibly with plasma proteins, tissue proteins, and with nucleic acids. This stable binding causes chemical alterations that are thought to contribute to drug toxicity either through changes in the functional properties of the modified molecules or through antigen formation with subsequent hypersensitivity and other immune reactions. Whereas in vitro data on the toxicity of acyl glucuronides have steadily accumulated, direct evidence for their toxicity in vivo is scarce. Acyl glucuronides display limited stability, which is dependent on pH, temperature, nature of the aglycon, and so on. Therefore, careful sample collection, handling, and storage procedures are critical to ensure generation of reliable pharmacologic and toxicologic data during clinical studies. Acyl glucuronides can be directly quantified in biologic specimens using chromatographic procedures. Their adducts with plasma or cell proteins can be determined after electrophoretic separation, followed by blotting. ELISA techniques have been used to assess the presence of antibodies against acyl glucuronide-protein adducts. This review summarizes the most recent evidence concerning biologic and toxicologic effects of acyl glucuronide metabolites of various drugs and discusses their relevance for drug monitoring. A critical evaluation of the available methodology is included.
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Affiliation(s)
- Maria Shipkova
- Department of Clinical Chemistry, Georg-August-University, Göttingen, Germany.
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Kohlert C, Schindler G, März RW, Abel G, Brinkhaus B, Derendorf H, Gräfe EU, Veit M. Systemic availability and pharmacokinetics of thymol in humans. J Clin Pharmacol 2002; 42:731-7. [PMID: 12092740 DOI: 10.1177/009127002401102678] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Essential oil compounds such as found in thyme extract are established for the therapy of chronic and acute bronchitis. Various pharmacodynamic activities for thyme extract and the essential thyme oil, respectively, have been demonstrated in vitro, but availability of these compounds in the respective target organs has not been proven. Thus, investigation of absorption, distribution, metabolism, and excretion are necessary to provide the link between in vitro effects and in vivo studies. To determine the systemic availability and the pharmacokinetics of thymol after oral application to humans, a clinical trial was carried out in 12 healthy volunteers. Each subject received a single dose of a Bronchipret TP tablet, which is equivalent to 1.08 mg thymol. No thymol could be detected in plasma or urine. However, the metabolites thymol sulfate and thymol glucuronide were found in urine and identified by LC-MS/MS. Plasma and urine samples were analyzed after enzymatic hydrolysis of the metabolites by headspace solid-phase microextraction prior to GC analysis and flame ionization detection. Thymol sulfate, but not thymol glucuronide, was detectable in plasma. Peak plasma concentrations were 93.1+/-24.5 ng ml(-1) and were reached after 2.0+/-0.8 hours. The mean terminal elimination half-life was 10.2 hours. Thymol sulfate was detectable up to 41 hours after administration. Urinary excretion could be followed over 24 hours. The amount of both thymol sulfate and glucuronide excreted in 24-hour urine was 16.2%+/-4.5% of the dose.
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Affiliation(s)
- Claudia Kohlert
- German Central Institute for Pharmaceutical Research, Sinzig
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Renwick AG, Lazarus NR. Human variability and noncancer risk assessment- An analysis of the default uncertainty factor. Regul Toxicol Pharmacol 1998; 27:3-20. [PMID: 9618319 DOI: 10.1006/rtph.1997.1195] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A 10-fold uncertainty factor is used for noncancer risk assessments to allow for possible interindividual differences between humans in the fate of the chemical in the body (kinetics) and target organ sensitivity (dynamics). Analysis of a database on the variability in each of these aspects is consistent with an even subdivision of the 10-fold factor into 10(0.5) (3.16) for kinetics and 10(0.5) (3.16) for dynamics. Analysis of the number of subjects in a normally and log-normally distributed population which would not be covered by factors of 3.16 supports this subdivision and also the use of a 10-fold factor to allow for both aspects. Analysis of kinetic data for subgroups of the population indicates that the standard default value of 3.16 for kinetics will not be adequate for all routes of elimination and all groups of the population. A scheme is proposed which would allow the selection of appropriate default uncertainty factors based on knowledge of the biological fate and effects of the chemical under review. Copyright 1998 Academic Press.
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Affiliation(s)
- AG Renwick
- Clinical Pharmacology Group, University of Southampton, Biomedical Sciences Building, Bassett Crescent East, Southampton, SO16 7PX, United Kingdom
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Vree TB, van den Biggelaar-Martea M, Verwey-van Wissen CP. Determination of furosemide with its acyl glucuronide in human plasma and urine by means of direct gradient high-performance liquid chromatographic analysis with fluorescence detection. Preliminary pharmacokinetics and effect of probenecid. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL APPLICATIONS 1994; 655:53-62. [PMID: 8061834 DOI: 10.1016/0378-4347(94)00093-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Furosemide is metabolized in humans by acyl glucuronidation to the 1-O-glucuronide (Fgluc). Furosemide (F) and the conjugate can be measured directly by gradient high-performance liquid chromatographic analysis without enzymic deglucuronidation. The glucuronide conjugate was isolated by preparative HPLC from human urine samples. Furosemide and its acyl glucuronide were present in plasma. No isoglucuronides were present in acidic urine of a volunteer. Calibration curves were constructed by enzymic deconjugation of samples containing different concentrations of isolated F-acyl glucuronide. The limit of quantitation of F in plasma is 0.007 microgram/ml, Fgluc 0.010 microgram/ml. The limits of quantitation in urine are respectively: F 0.10 microgram/ml, Fgluc 0.15 microgram/ml. A pharmacokinetic profile of furosemide is shown, and some preliminary pharmacokinetic parameters of furosemide obtained from one human volunteer are given. Probenecid does not inhibit the formation of the acyl glucuronide of F, but inhibits the renal clearance of both compounds.
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Affiliation(s)
- T B Vree
- Department of Clinical Pharmacy, Academic Hospital Nijmegen Sint Radboud, Netherlands
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