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Feldman K, Kearns GL, Pearce RE, Abdel-Rahman SM, Leeder JS, Friesen A, Staggs VS, Gaedigk A, Weigel J, Shakhnovich V. Utility of the 13 C-pantoprazole breath test as a CYP2C19 phenotyping probe for children. Clin Transl Sci 2022; 15:1155-1166. [PMID: 35099109 PMCID: PMC9099127 DOI: 10.1111/cts.13232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/29/2022] Open
Abstract
The 13 C-pantoprazole breath test (PAN-BT) is a safe, non-invasive, in-vivo CYP2C19 phenotyping probe for adults. Our objective was to evaluate PAN-BT performance in children, with a focus on discriminating individuals who, according to guidelines from the Clinical Pharmacology Implementation Consortium (CPIC), would benefit from starting dose escalation vs. reduction for proton pump inhibitors (PPIs). Children (n=65; 6-17 years) genotyped for CYP2C19 variants *2, *3, *4, and *17 received a single oral dose of 13 C-pantoprazole. Plasma concentrations of pantoprazole and its metabolites, and changes in exhaled 13 CO2 (termed delta-over-baseline or DOB), were measured 10 times over 8 hours using HPLC-UV and spectrophotometry, respectively. Pharmacokinetic parameters of interest were generated and DOB features derived using feature engineering for the first 180 minutes post-administration. DOB features, age, sex, and obesity status were used to run bootstrap analysis at each timepoint (Ti) independently. For each iteration, stratified samples were drawn based on genotype prevalence in the original cohort. A random forest was trained, and predictive performance of PAN-BT evaluated. Strong discriminating ability for CYP2C19 intermediate vs. normal/rapid metabolizer phenotype was noted at DOBT30min (mean sensitivity: 0.522, specificity: 0.784), with consistent model outperformance over a random or a stratified classifier approach at each time-point (p<0.001). With additional refinement and investigation, the test could become a useful and convenient dosing tool in clinic to help identify children who would benefit most from PPI dose escalation vs. dose reduction, in accordance with CPIC guidelines.
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Affiliation(s)
- Keith Feldman
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - Gregory L Kearns
- Texas Christian University and UNTHSC School of Medicine, Fort Worth, TX, USA
| | - Robin E Pearce
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - Susan M Abdel-Rahman
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - J Steven Leeder
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - Alec Friesen
- Oklahoma School of Community Medicine, Tulsa, OK, USA
| | - Vincent S Staggs
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - Andrea Gaedigk
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA
| | - Jaylene Weigel
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA
| | - Valentina Shakhnovich
- University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.,Children's Mercy Kansas City, Kansas City, MO, USA.,Center for Children's Healthy Lifestyles & Nutrition, Kansas City, MO, USA
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2
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Keller J, Hammer HF, Afolabi PR, Benninga M, Borrelli O, Dominguez-Munoz E, Dumitrascu D, Goetze O, Haas SL, Hauser B, Pohl D, Salvatore S, Sonyi M, Thapar N, Verbeke K, Fox MR. European guideline on indications, performance and clinical impact of 13 C-breath tests in adult and pediatric patients: An EAGEN, ESNM, and ESPGHAN consensus, supported by EPC. United European Gastroenterol J 2021; 9:598-625. [PMID: 34128346 PMCID: PMC8259225 DOI: 10.1002/ueg2.12099] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/06/2021] [Indexed: 12/20/2022] Open
Abstract
Introduction 13C‐breath tests are valuable, noninvasive diagnostic tests that can be widely applied for the assessment of gastroenterological symptoms and diseases. Currently, the potential of these tests is compromised by a lack of standardization regarding performance and interpretation among expert centers. Methods This consensus‐based clinical practice guideline defines the clinical indications, performance, and interpretation of 13C‐breath tests in adult and pediatric patients. A balance between scientific evidence and clinical experience was achieved by a Delphi consensus that involved 43 experts from 18 European countries. Consensus on individual statements and recommendations was established if ≥ 80% of reviewers agreed and <10% disagreed. Results The guideline gives an overview over general methodology of 13C‐breath testing and provides recommendations for the use of 13C‐breath tests to diagnose Helicobacter pylori infection, measure gastric emptying time, and monitor pancreatic exocrine and liver function in adult and pediatric patients. Other potential applications of 13C‐breath testing are summarized briefly. The recommendations specifically detail when and how individual 13C‐breath tests should be performed including examples for well‐established test protocols, patient preparation, and reporting of test results. Conclusion This clinical practice guideline should improve pan‐European harmonization of diagnostic approaches to symptoms and disorders, which are very common in specialist and primary care gastroenterology practice, both in adult and pediatric patients. In addition, this guideline identifies areas of future clinical research involving the use of 13C‐breath tests.
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Affiliation(s)
- Jutta Keller
- Department of Internal Medicine, Israelitic Hospital, Academic Hospital University of Hamburg, Hamburg, Germany
| | - Heinz F Hammer
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria
| | - Paul R Afolabi
- NIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
| | - Marc Benninga
- Department of Pediatric Gastroenterology, Hepatology and Nutrition, Emma Children's Hospital, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Osvaldo Borrelli
- UCL Great Ormond Street Institute of Child Health and Department of Gastroenterology, Neurogastroenterology and Motility, Great Ormond Street Hospital, London, UK
| | - Enrique Dominguez-Munoz
- Department of Gastroenterology and Hepatology, University Hospital of Santiago de Compostela, Santiago, Spain
| | | | - Oliver Goetze
- Department of Medicine II, Division of Hepatology, University Hospital Würzburg, Würzburg, Germany
| | - Stephan L Haas
- Department of Upper GI Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Bruno Hauser
- Department of Paediatric Gastroenterology, Hepatology and Nutrition, KidZ Health Castle UZ Brussels, Brussels, Belgium
| | - Daniel Pohl
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland
| | - Silvia Salvatore
- Pediatric Department, Hospital "F. Del Ponte", University of Insubria, Varese, Italy
| | - Marc Sonyi
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Medical University of Graz, Graz, Austria.,Clinic for General Medicine, Gastroenterology, and Infectious Diseases, Augustinerinnen Hospital, Cologne, Germany
| | - Nikhil Thapar
- UCL Great Ormond Street Institute of Child Health and Department of Gastroenterology, Neurogastroenterology and Motility, Great Ormond Street Hospital, London, UK.,Department of Gastroenterology, Hepatology and Liver Transplantation, Queensland Children's Hospital, Brisbane, Australia
| | - Kristin Verbeke
- Translational Research Center for Gastrointestinal Disorders, KU Leuven, Leuven, Belgium
| | - Mark R Fox
- Division of Gastroenterology and Hepatology, University Hospital Zürich, Zürich, Switzerland.,Digestive Function: Basel, Laboratory and Clinic for Motility Disorders and Functional Gastrointestinal Diseases, Centre for Integrative Gastroenterology, Klinik Arlesheim, Arlesheim, Switzerland
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3
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Kaartinen TJK, Tornio A, Tapaninen T, Launiainen T, Isoherranen N, Niemi M, Backman JT. Effect of High‐Dose Esomeprazole on CYP1A2, CYP2C19, and CYP3A4 Activities in Humans: Evidence for Substantial and Long‐lasting Inhibition of CYP2C19. Clin Pharmacol Ther 2020; 108:1254-1264. [DOI: 10.1002/cpt.1949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 06/04/2020] [Indexed: 12/11/2022]
Affiliation(s)
- Taavi J. K. Kaartinen
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
- Individualized Drug Therapy Research Program Faculty of Medicine University of Helsinki Helsinki Finland
| | - Aleksi Tornio
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
- Individualized Drug Therapy Research Program Faculty of Medicine University of Helsinki Helsinki Finland
- Integrative Physiology and Pharmacology Institute of Biomedicine, University of Turku Turku Finland
- Unit of Clinical Pharmacology Turku University Hospital Turku Finland
| | - Tuija Tapaninen
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
- Individualized Drug Therapy Research Program Faculty of Medicine University of Helsinki Helsinki Finland
| | - Terhi Launiainen
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
| | - Nina Isoherranen
- Department of Pharmaceutics School of Pharmacy University of Washington Seattle Washington USA
| | - Mikko Niemi
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
- Individualized Drug Therapy Research Program Faculty of Medicine University of Helsinki Helsinki Finland
| | - Janne T. Backman
- Department of Clinical Pharmacology Faculty of Medicine University of Helsinki and HUS Helsinki University Hospital Helsinki Finland
- Individualized Drug Therapy Research Program Faculty of Medicine University of Helsinki Helsinki Finland
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4
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Effects of genetic polymorphisms on the pharmacokinetics and pharmacodynamics of proton pump inhibitors. Pharmacol Res 2020; 152:104606. [DOI: 10.1016/j.phrs.2019.104606] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 02/06/2023]
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Modak AS. Point-of-care companion diagnostic tests for personalizing psychiatric medications: fulfilling an unmet clinical need. J Breath Res 2017; 12:017101. [PMID: 28920579 DOI: 10.1088/1752-7163/aa8d2e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Over the last decade stable isotope-labeled substrates have been used as probes for rapid, point-of-care, non-invasive and user-friendly phenotype breath tests to evaluate activity of drug metabolizing enzymes. These diagnostic breath tests can potentially be used as companion diagnostics by physicians to personalize medications, especially psychiatric drugs with narrow therapeutic windows, to monitor the progress of disease severity, medication efficacy and to study in vivo the pharmacokinetics of xenobiotics. Several genotype tests have been approved by the FDA over the last 15 years for both cytochrome P450 2D6 and 2C19 enzymes, however they have not been cleared for use in personalizing medications since they fall woefully short in identifying all non-responders to drugs, especially for the CYP450 enzymes. CYP2D6 and CYP2C19 are among the most extensively studied drug metabolizing enzymes, involved in the metabolism of approximately 30% of FDA-approved drugs in clinical use, associated with large individual differences in medication efficacy or tolerability essentially due to phenoconversion. The development and commercialization via FDA approval of the non-invasive, rapid (<60 min), in vivo, phenotype diagnostic breath tests to evaluate polymorphic CYP2D6 and CYP2C19 enzyme activity by measuring exhaled 13CO2 as a biomarker in breath will effectively resolve the currently unmet clinical need for individualized psychiatric drug therapy. Clinicians could personalize treatment options for patients based on the CYP2D6 and CYP2C19 phenotype by selecting the optimal medication at the right initial and subsequent maintenance dose for the desired clinical outcome (i.e. greatest efficacy and minimal side effects).
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Affiliation(s)
- Anil S Modak
- Cambridge Isotope Laboratories, Inc., 3 Highwood Drive, Tewksbury, MA 01876, United States of America
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6
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Modak AS, Klyarytska I, Kriviy V, Tsapyak T, Rabotyagova Y. The effect of proton pump inhibitors on the CYP2C19 enzyme activity evaluated by the pantoprazole-
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C breath test in GERD patients: clinical relevance for personalized medicine. J Breath Res 2016; 10:046017. [DOI: 10.1088/1752-7163/10/4/046017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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7
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De Kesel PMM, Lambert WE, Stove CP. Alternative Sampling Strategies for Cytochrome P450 Phenotyping. Clin Pharmacokinet 2015; 55:169-84. [DOI: 10.1007/s40262-015-0306-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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8
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Klieber M, Oberacher H, Hofstaetter S, Beer B, Neururer M, Amann A, Alber H, Modak A. CYP2C19 Phenoconversion by Routinely Prescribed Proton Pump Inhibitors Omeprazole and Esomeprazole: Clinical Implications for Personalized Medicine. J Pharmacol Exp Ther 2015; 354:426-30. [PMID: 26159874 DOI: 10.1124/jpet.115.225680] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/08/2015] [Indexed: 12/23/2022] Open
Abstract
The phenotype pantoprazole-(13)C breath test (Ptz-BT) was used to evaluate the extent of phenoconversion of CYP2C19 enzyme activity caused by commonly prescribed proton pump inhibitors (PPI) omeprazole and esomprazole. The Ptz-BT was administered to 26 healthy volunteers and 8 stable cardiovascular patients twice at baseline and after 28 days of PPI therapy to evaluate reproducibility of the Ptz-BT and changes in CYP2C19 enzyme activity (phenoconversion) after PPI therapy. The average intrapatient interday variability in CYP2C19 phenotype (n = 31) determined by Ptz-BT was considerably low (coefficient of variation, 17%). Phenotype conversion resulted in 25 of 26 (96%) nonpoor metabolizer (non-PM) volunteers/patients as measured by the Ptz-BT at baseline and after PPI therapy. The incidence of PM status by phenotype following administration of omeprazole/esomeprazole (known inhibitors of CYP2C19) was 10-fold higher than those who are genetically PMs in the general population, which could have critical clinical implications for personalizing medications primarily metabolized by CYP2C19, such as clopidogrel, PPI, cyclophosphamide, thalidomide, citalopram, clonazepam, diazepam, phenytoin, etc. The Ptz-BT can rapidly (30 minutes) evaluate CYP2C19 phenotype and, more importantly, can identify patients with phenoconversion in CYP2C19 enzyme activity caused by nongenetic factors such as concomitant drugs.
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Affiliation(s)
- Martin Klieber
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Herbert Oberacher
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Silvia Hofstaetter
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Beate Beer
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Martin Neururer
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Anton Amann
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Hannes Alber
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
| | - Anil Modak
- Breath Research Institute of University of Innsbruck, Dornbirn, Austria (M.K., M.N., A.A.); Department of Anesthesiology and Critical Care Medicine (M.K., M.N., A.A.), Institute of Legal Medicine and Core Facility Metabolomics (H.O., S.H., B.B.), and University Clinic for Internal Medicine III (Cardiology) (H.A.), Innsbruck Medical University, Innsbruck, Austria; Department of Cardiology, Rehabilitation Centre Münster in Tyrol, Münster, Austria (H.A.); and Cambridge Isotopes Laboratories, Tewksbury, Massachusetts (A.M.)
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9
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Opdam FL, Modak AS, Gelderblom H, Guchelaar HJ. Further characterization of a
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C-dextromethorphan breath test for CYP2D6 phenotyping in breast cancer patients on tamoxifen therapy. J Breath Res 2015; 9:026003. [DOI: 10.1088/1752-7155/9/2/026003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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10
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Shah RR, Smith RL. Addressing phenoconversion: the Achilles' heel of personalized medicine. Br J Clin Pharmacol 2015; 79:222-40. [PMID: 24913012 PMCID: PMC4309629 DOI: 10.1111/bcp.12441] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 06/04/2014] [Indexed: 02/06/2023] Open
Abstract
Phenoconversion is a phenomenon that converts genotypic extensive metabolizers (EMs) into phenotypic poor metabolizers (PMs) of drugs, thereby modifying their clinical response to that of genotypic PMs. Phenoconversion, usually resulting from nongenetic extrinsic factors, has a significant impact on the analysis and interpretation of genotype-focused clinical outcome association studies and personalizing therapy in routine clinical practice. The high phenotypic variability or genotype-phenotype mismatch, frequently observed due to phenoconversion within the genotypic EM population, means that the real number of phenotypic PM subjects may be greater than predicted from their genotype alone, because many genotypic EMs would be phenotypically PMs. If the phenoconverted population with genotype-phenotype mismatch, most extensively studied for CYP2D6, is as large as the evidence suggests, there is a real risk that genotype-focused association studies, typically correlating only the genotype with clinical outcomes, may miss clinically strong pharmacogenetic associations, thus compromising any potential for advancing the prospects of personalized medicine. This review focuses primarily on co-medication-induced phenoconversion and discusses potential approaches to rectify some of the current shortcomings. It advocates routine phenotyping of subjects in genotype-focused association studies and proposes a new nomenclature to categorize study populations. Even with strong and reliable data associating patients' genotypes with clinical outcome(s), there are problems clinically in applying this knowledge into routine pharmacotherapy because of potential genotype-phenotype mismatch. Drug-induced phenoconversion during routine clinical practice remains a major public health issue. Therefore, the principal challenges facing personalized medicine, which need to be addressed, include identification of the following factors: (i) drugs that are susceptible to phenoconversion; (ii) co-medications that can cause phenoconversion; and (iii) dosage amendments that need to be applied during and following phenoconversion.
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Affiliation(s)
| | - Robert L Smith
- Department of Surgery and Cancer, Faculty of Medicine, Imperial CollegeLondon, UK
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11
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Modak AS. Regulatory issues on breath tests and updates of recent advances on [
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C]-breath tests. J Breath Res 2013; 7:037103. [DOI: 10.1088/1752-7155/7/3/037103] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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12
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Thacker DL, Modak A, Flockhart DA, Desta Z. Is (+)-[13C]-pantoprazole better than (±)-[13C]-pantoprazole for the breath test to evaluate CYP2C19 enzyme activity? J Breath Res 2012; 7:016001. [PMID: 23257668 DOI: 10.1088/1752-7155/7/1/016001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Recently, we have shown that the (+)-[(13)C]-pantoprazole is more dependent on CYP2C19 metabolic status than (-)-[(13)C]-pantoprazole. In this study, we tested the hypothesis that (+)-[(13)C]-pantoprazole is a more sensitive and selective probe for evaluating CYP2C19 enzyme activity than the racemic mixture. (+)-[(13)C]-pantoprazole (95 mg) was administered orally in a sodium bicarbonate solution to healthy volunteers. Breath and plasma samples were collected before and up to 720 min after dosing. The (13)CO2 in exhaled breath samples was measured by infrared spectrometry. Ratios of (13)CO2/(12)CO2 after (+)-[(13)C]-pantoprazole relative to (13)CO2/(12)CO2 at baseline were expressed as delta over baseline (DOB). (+)-[(13)C]-pantoprazole concentrations were measured by HPLC. Genomic DNA extracted from whole blood was genotyped for CYP2C19*2, *3 and *17 using Taqman assays. Statistically significant differences in the area under the plasma concentration time curve (AUCplasma(0-∞) (p < 0.001) and oral clearance (<0.01) of (+)-[(13)C]-pantoprazole as well as in the breath test indices (delta over baseline, DOB30; and area under the DOB versus time curve, AUCDOB(0-120)) (p < 0.01) were observed among poor, intermediate and extensive metabolizer of CYP2C19. DOB30 and AUCDOB(0-120) adequately distinguished poor metabolizer from intermediate and extensive metabolizer of CYP2C19. Breath test indices significantly correlated with plasma elimination parameters of (+)-[(13)C]-pantoprazole (Pearson correlations: -0.68 to -0.73). Although relatively higher breath test indices were observed after administration of (+)-[(13)C]-pantoprazole (this study) than after (±)-[(13)C]-pantoprazole (previous study), the performance of the racemic and the enantiomer as marker of CYP2C19 activity remained similar. Our data confirm that the metabolism of (+)-[(13)C]-pantoprazole is highly dependent on CYP2C19 metabolic status, but the breath test derived from it is not superior to the racemic [(13)C]-pantoprazole in evaluating CYP2C19 activity in vivo. Thus, racemic [(13)C]-pantoprazole which is relatively easy to synthesize and more stable than (+)-[(13)C]-pantoprazole is adequate as a probe of this enzyme.
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Affiliation(s)
- David L Thacker
- Indiana University School of Medicine, Indiana University, Indianapolis, IN, USA
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13
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Individualized therapy for gastroesophageal reflux disease: potential impact of pharmacogenetic testing based on CYP2C19. Mol Diagn Ther 2012; 16:223-34. [PMID: 22873740 DOI: 10.1007/bf03262211] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The main therapeutic agent for gastroesophageal reflux disease (GERD) is a proton pump inhibitor (PPI). Plasma levels and the acid inhibitory effect of PPIs depend on the activity of cytochrome P450 (CYP) 2C19, which is polymorphic. Genotypes of CYP2C19 are classified into three groups: rapid metabolizers (RMs: *1/*1), intermediate metabolizers (IMs: *1/*X), and poor metabolizers (PMs: *X/*X), where *1 and X represent the wild type and the mutant allele, respectively. RMs include ultra-rapid metabolizers, who possess the CYP2C19*17 allele. The pharmacokinetics and pharmacodynamics of PPIs differ among different CYP2C19 genotype groups. Plasma PPI levels and intragastric pH values during PPI treatment are lowest in the RM group, intermediate in the IM group, and highest in the PM group. These CYP2C19-genotype-dependent differences in the pharmacokinetics and pharmacodynamics of PPIs influence the healing and recurrence of GERD during PPI treatment, suggesting the need for CYP2C19 genotype-based tailored therapy for GERD. CYP2C19 pharmacogenetics should be taken into consideration for the personalization of PPI-based therapy. However, the clinical usefulness of CYP2C19 genotype testing in GERD therapy should be verified in clinical studies.
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Furuta T, Sugimoto M, Shirai N. Individualized therapy for gastroesophageal reflux disease: potential impact of pharmacogenetic testing based on CYP2C19. Mol Diagn Ther 2012. [PMID: 22873740 DOI: 10.2165/11634960-000000000-00000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The main therapeutic agent for gastroesophageal reflux disease (GERD) is a proton pump inhibitor (PPI). Plasma levels and the acid inhibitory effect of PPIs depend on the activity of cytochrome P450 (CYP) 2C19, which is polymorphic. Genotypes of CYP2C19 are classified into three groups: rapid metabolizers (RMs: *1/*1), intermediate metabolizers (IMs: *1/*X), and poor metabolizers (PMs: *X/*X), where *1 and X represent the wild type and the mutant allele, respectively. RMs include ultra-rapid metabolizers, who possess the CYP2C19*17 allele. The pharmacokinetics and pharmacodynamics of PPIs differ among different CYP2C19 genotype groups. Plasma PPI levels and intragastric pH values during PPI treatment are lowest in the RM group, intermediate in the IM group, and highest in the PM group. These CYP2C19-genotype-dependent differences in the pharmacokinetics and pharmacodynamics of PPIs influence the healing and recurrence of GERD during PPI treatment, suggesting the need for CYP2C19 genotype-based tailored therapy for GERD. CYP2C19 pharmacogenetics should be taken into consideration for the personalization of PPI-based therapy. However, the clinical usefulness of CYP2C19 genotype testing in GERD therapy should be verified in clinical studies.
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Affiliation(s)
- Takahisa Furuta
- Center for Clinical Research, Hamamatsu University School of Medicine, Hamamatsu, Japan.
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Tazaki J, Jinnai T, Tada T, Kato Y, Makiyama T, Ikeda T, Yamane K, Naruse Y, Takahashi K, Watanabe H, Kimura T, Horiuchi H. Prediction of Clopidogrel Low Responders by a Rapid CYP2C19 Activity Test. J Atheroscler Thromb 2012; 19:186-93. [DOI: 10.5551/jat.10009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Gumus E, Karaca O, Babaoglu MO, Baysoy G, Balamtekin N, Demir H, Uslu N, Bozkurt A, Yuce A, Yasar U. Evaluation of lansoprazole as a probe for assessing cytochrome P450 2C19 activity and genotype-phenotype correlation in childhood. Eur J Clin Pharmacol 2011; 68:629-36. [PMID: 22076562 DOI: 10.1007/s00228-011-1151-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 10/17/2011] [Indexed: 02/06/2023]
Abstract
PURPOSE Lansoprazole, a cytochrome P450 2C19 (CYP2C19) substrate, has been widely used in children to manage acid-related diseases. CYP2C19 exhibits marked genetic polymorphisms, and distribution of these polymorphisms varies among different ethnic groups. There is limited data regarding the use of probe drugs for determining CYP2C19 activity in children. The aim of this study was to evaluate lansoprazole as an in vivo phenotyping probe for assessing CYP2C19 activity in children. METHODS The CYP2C19*2, *3, and *17 variants were determined in 244 children. Three hours after a single oral dose of lansoprazole (n = 94) or omeprazole (n = 19), plasma lansoprazole and 5-hydroxy lansoprazole or omeprazole and 5-hydroxy omeprazole concentrations were analyzed by high-performance liquid chromatography. RESULTS The CYP2C19*17 was the most frequent variant allele (24.4%). The group of patients with CYP2C19*17*17 genotype had a 70% lower (p < 0.05) mean lansoprazole plasma concentration compared with the CYP2C19*1*1 genotype group, whereas the CYP2C19*2*2 group had 6.9-fold higher (p < 0.01) mean lansoprazole plasma concentration. Lansoprazole metabolic ratios (lansoprazole/5-hydroxy-lansoprazole) were found to be significantly lower in the *17*17 [mean ± standard deviation (SD); 2.8 ± 2.1] group and higher in the *2*2 group (63.5 ± 12.2) compared with that of the *1*1 genotype group (6.1 ± 4.5). CONCLUSION According to our results from a Turkish pediatric population, lansoprazole is a suitable probe drug for phenotyping CYP2C19. The CYP2C19*2 and *17 variants should be taken into consideration in predicting the clinical outcome of therapy with lansoprazole in the pediatric population.
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Affiliation(s)
- Ersin Gumus
- Department of Pharmacology, Faculty of Medicine, Hacettepe University, Sihhiye, Ankara, Turkey
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Thacker DL, Modak A, Nguyen PD, Flockhart DA, Desta Z. Stereoselective pharmacokinetics of stable isotope (+/-)-[13C]-pantoprazole: Implications for a rapid screening phenotype test of CYP2C19 activity. Chirality 2011; 23:904-9. [PMID: 21935988 DOI: 10.1002/chir.21011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 07/06/2011] [Indexed: 12/20/2022]
Abstract
AIMS We have previously shown that the (±)-[(13) C]-pantoprazole breath test is a promising noninvasive probe of CYP2C19 activity. As part of that trial, plasma, breath test indices and CYP2C19 (*2, *3, and *17) genotype were collected. Here, we examined whether [(13) C]-pantoprazole exhibits enantioselective pharmacokinetics and whether this enantioselectivity is correlated with indices of breath test. METHODS Plasma (-)- and (+)-[(13) C]-pantoprazole that were measured using a chiral HPLC were compared between CYP2C19 genotypes and correlated with breath test indices. RESULTS The AUC( 0-∞) of (+)-[(13) C]-pantoprazole in PM (*2/*2, n = 4) was 10.1- and 5.6-fold higher that EM (*1/*1or *17, n = 10) and IM (*1/*2or *3, n = 10) of CYP2C19, respectively (P < 0.001). The AUC( 0-∞) of (-)-[(13) C]-pantoprazole only significantly differed between PMs and EMs (1.98-fold; P = 0.05). The AUC( 0-∞) ratio of (+)-/(-)-[(13) C]-pantoprazole was 3.45, 0.77, and 0.67 in PM, IM, and EM genotypes, respectively. Breath test index, delta over baseline show significant correlation with AUC( 0-∞) of (+)-[(13) C]-pantoprazole (Pearson's r = 0.62; P < 0.001). CONCLUSIONS [(13) C]-pantoprazole exhibits enantioselective elimination. (+)-[(13) C]-pantoprazole is more dependent on CYP2C19 metabolic status and may serve as a more attractive probe of CYP2C19 activity than (-)-[(13) C]-pantoprazole or the racemic mixture.
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Affiliation(s)
- David L Thacker
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Wishard Memorial Hospital, Indianapolis, Indiana
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Abstract
Personalized medicine, in the near future, has the potential to revolutionize healthcare by allowing physicians to individualize therapy for patients through the early diagnosis of disease and risk assessment to optimize clinical response with minimal toxicity. The identification of biomarkers could detect, diagnose and help guide therapy to improve survival and quality of life by the early identification of responders to the drugs. Volatile organic compounds and stable isotope-labeled 13CO2 in breath can be uniquely utilized as in vivo diagnostic biomarkers of disease and/or lack of enzyme activity to aid physicians to personalize medication. Noninvasive detection of ailments and monitoring therapy by human breath analysis is an emerging field of medical diagnostics representing a rapid, economic and simple alternative to standard invasive blood analysis, endoscopy or harmful imaging techniques such as x-ray and CT scans.
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Affiliation(s)
- Anil S Modak
- Cambridge Isotope Laboratories Inc., Andover, MA 01810, USA
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[13C]Pantoprazole breath test as a predictor of the anti-platelet function of clopidogrel. Eur J Clin Pharmacol 2010; 66:457-63. [DOI: 10.1007/s00228-010-0807-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Accepted: 02/23/2010] [Indexed: 11/26/2022]
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