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Emoto C, Johnson TN. Cytochrome P450 enzymes in the pediatric population: Connecting knowledge on P450 expression with pediatric pharmacokinetics. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 95:365-391. [PMID: 35953161 DOI: 10.1016/bs.apha.2022.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Cytochrome P450 enzymes play an important role in the pharmacokinetics, efficacy, and toxicity of drugs. Age-dependent changes in P450 enzyme expression have been studied based on several detection systems, as well as by deconvolution of in vivo pharmacokinetic data observed in pediatric populations. The age-dependent changes in P450 enzyme expression can be important determinants of drug disposition in childhood, in addition to the changes in body size and the other physiological parameters, and effects of pharmacogenetics and disease on organ functions. As a tool incorporating drug-specific and body-specific factors, physiologically-based pharmacokinetic (PBPK) models have become increasingly used to characterize and explore mechanistic insights into drug disposition. Thus, PBPK models can be a bridge between findings from basic science and utilization in predictive science. Pediatric PBPK models incorporate additional system specific information on developmental physiology and ontogeny and have been used to predict pharmacokinetic parameters from preterm neonates onwards. These models have been advocated by regulatory authorities in order to support pediatric clinical trials. The purpose of this chapter is to highlight accumulated knowledge and findings from basic research focusing on P450 enzymes, as well as the current status and future challenges of expanding the utilization of pediatric PBPK modeling.
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Affiliation(s)
- Chie Emoto
- Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Tokyo, Japan; Translational Research Division, Chugai Pharmaceutical Co., Ltd., Tokyo, Japan.
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Acidity of Enteral Feeding Tube Aspirate in Neonates: Do pH Values Meet the Cutoff for Predicting Gastric Placement? Adv Neonatal Care 2019; 19:333-341. [PMID: 30720480 DOI: 10.1097/anc.0000000000000591] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Enteral feeding tubes (EFTs) are commonly used in neonatal practice, but complications from tube misplacement remain a concern. Measuring the pH of EFT aspirate is a recommended method to evaluate EFT placement. A pH value of ≤5.5 is considered predictive of gastric placement. Using this method in infants has been questioned. It is unclear whether infants can produce adequate gastric acid to achieve a pH 5 or less and whether feedings and medications influence pH. PURPOSE To report EFT aspirate pH values in infants and to evaluate factors potentially influencing pH values. METHODS A retrospective descriptive study was conducted with 1024 infants with 6979 pH values. Demographic and clinical data were collected including type of EFT, pH of gastric aspirate, feeding method, time of last feeding, and administration of acid suppression medications. The frequency of measured pH values of 5 or less was calculated for each covariate. FINDINGS/RESULTS The majority (97.51%) of pH values were 5 or less. Orogastric tubes, continuous feeding, a 4-hour or more feeding interval, exposure to medications (proton pump inhibitor, histamine-2 receptor antagonist, or multiple medications) were associated with an increased likelihood of pH values of more than 5. However, with each study variable the majority of pH values were 5 or less. IMPLICATIONS FOR PRACTICE These findings suggest EFT pH, a recommended method to evaluate the likelihood of gastric placement, can be successfully used in the neonatal population. IMPLICATIONS FOR RESEARCH Future research should prospectively evaluate EFT pH in infants when compared with clinically indicated radiographs. Other factors that might influence pH should be explored including severity of illness, feeding type, and other medications.
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Upreti VV, Wahlstrom JL. Meta-analysis of hepatic cytochrome P450 ontogeny to underwrite the prediction of pediatric pharmacokinetics using physiologically based pharmacokinetic modeling. J Clin Pharmacol 2015; 56:266-83. [DOI: 10.1002/jcph.585] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 06/29/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Vijay V. Upreti
- Clinical Pharmacology, Modeling and Simulation; Amgen, Inc.; South San Francisco CA USA
| | - Jan L. Wahlstrom
- Pharmacokinetics and Drug Metabolism; Amgen, Inc.; Thousand Oaks CA USA
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Abstract
BACKGROUND To develop a population pharmacokinetic model for intravenous omeprazole in critically ill children. METHODS One hundred eighty-six omeprazole concentration-time data from 40 critically ill children were analyzed using the nonlinear mixed-effects approach with the nonlinear mixed-effects modeling software, version 7.2 software. Patients were randomized into 2 groups and received intravenous omeprazole at a dose of 0.5 or 1 mg/kg twice daily. Blood samples were drawn at 0.5, 2, 6, 12, 24, and 48 hours after the first infusion. RESULTS The pharmacokinetic profile was best described by a 2-compartment model with a first-order elimination process. Between-patient variability could only be associated with plasma clearance (CL). The typical values for plasma CL were 24.9 L·h·70 kg (10.08%), with a distributional clearance of 53.9 L·h·70 kg (11.00%) and central and peripheral compartment distribution volumes of 4.23 L/70 kg (19.62%) and 674 L/70 kg (0.89%), respectively. Allometric size models seemed to predict changes adequately in all the pharmacokinetic parameters. High values of between-patient variability of CL [75.50% (2.60%)] and residual variability [130.0% (5.26%)] were still found in the final model. Model-based simulations suggested that the most suitable dose was 1 mg/kg because this yielded similar exposure (defined by the area under the concentration-time curve) to that obtained in adults after a 20-mg dose of omeprazole intravenously. CONCLUSIONS An allometric size model allows changes to be predicted in all the pharmacokinetic parameters, making dose adjustment by body weight important to achieve the most effective omeprazole exposure. This is the first step toward a population pharmacokinetic study, including more data to develop a predictable model to be used during therapeutic drug monitoring.
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Ward RM, Kearns GL. Proton pump inhibitors in pediatrics : mechanism of action, pharmacokinetics, pharmacogenetics, and pharmacodynamics. Paediatr Drugs 2013; 15:119-31. [PMID: 23512128 PMCID: PMC3616221 DOI: 10.1007/s40272-013-0012-x] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Proton pump inhibitors (PPIs) have become some of the most frequently prescribed medications for treatment of adults and children. Their effectiveness for treatment of peptic conditions in the pediatric population, including gastric ulcers, gastroesophageal reflux disease (GERD), and Helicobacter pylori infections has been established for children older than 1 year. Studies of the preverbal population of neonates and infants have identified doses that inhibit acid production, but the effectiveness of PPIs in the treatment of GERD has not been established except for the recent approval of esomeprazole treatment of erosive esophagitis in infants. Reasons that have been proposed for this are complex, ranging from GERD not occurring in this population to a lack of histologic identification of esophagitis related to GERD to questions about the validity of symptom scoring systems to identify esophagitis when it occurs in infants. The effectiveness of PPIs relates to their structures, which must undergo acidic activation within the parietal cell to allow the PPI to be ionized and form covalent disulfide bonds with cysteines of the H(+)-K(+)-adenosine triphosphatase (H(+)-K(+)-ATPase). Once the PPI binds to the proton pump, the pump is inactivated. Some PPIs, such as omeprazole and rabeprazole bind to cysteines that are exposed, and their binding can be reversed. After irreversible chemical inhibition of the proton pump, such as occurs with pantoprazole, the recovery of the protein of the pump has a half-life of around 50 h. Cytochrome P450 (CYP) 2C19 and to a lesser degree CYP3A4 clear the PPIs metabolically. These enzymes are immature at birth and reach adult levels of activity by 5-6 months after birth. This parallels studies of the maturation of CYP2C19 to adult levels by roughly the same age after birth. Specific single nucleotide polymorphisms of CYP2C19 reduce clearance proportionally and increase exposure and prolong proton pump inhibition. Prolonged treatment of pediatric patients with PPIs has not caused cancer or significant abnormalities.
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Affiliation(s)
- Robert M. Ward
- Neonatology, University of Utah, 295 Chipeta Way, Salt Lake City, UT 84108 USA
| | - Gregory L. Kearns
- Division of Pediatric Pharmacology and Medical Toxicology, The Departments of Pediatrics and Pharmacology, Children’s Mercy Hospital, University of Missouri, Kansas City, MO 64108 USA
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Funk RS, Brown JT, Abdel-Rahman SM. Pediatric pharmacokinetics: human development and drug disposition. Pediatr Clin North Am 2012; 59:1001-16. [PMID: 23036241 DOI: 10.1016/j.pcl.2012.07.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Human development is described by the various anatomic and physiologic changes that occur as the single-celled zygote matures into an adult human being. Concomitant with bodily maturation are changes in the complex interactions between pharmacologic agents and the biologic matrix that is the human body. Profound changes in the manner by which drugs traverse the body during development can have significant implications in drug efficacy and toxicity. Although not a replacement for well-conducted, pediatric, pharmacokinetic studies, an understanding of developmental biology and the mechanisms for drug disposition invariably assists the pediatric clinician with the judicious use of medications in children.
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Affiliation(s)
- Ryan S Funk
- Division of Clinical Pharmacology and Medical Toxicology, Children's Mercy Hospitals and Clinics, 2401 Gillham Road, Kansas City, MO 64108, USA
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Sandström M, Davidson G, Tolia V, Sullivan JE, Långström G, Lundborg P, Brown K. Phase I, multicenter, randomized, open-label study evaluating the pharmacokinetics and safety profile of repeated once-daily doses of intravenous esomeprazole in children 0 to 17 years of age. Clin Ther 2012; 34:1828-38. [PMID: 22832034 DOI: 10.1016/j.clinthera.2012.06.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/20/2012] [Accepted: 06/26/2012] [Indexed: 12/15/2022]
Abstract
BACKGROUND Several oral proton pump inhibitors (PPIs) are currently approved for use in pediatric patients in North America and Europe. However, when use of oral therapy is not possible or appropriate, intravenous formulations of PPIs may be helpful. Intravenous esomeprazole is approved in the United States for the short-term treatment of gastroesophageal reflux disease (GERD) with erosive esophagitis in adults and in pediatric patients 1 month to 17 years of age (inclusive) as an alternative to oral therapy. Four open-label, randomized, 2-way crossover studies in adults with GERD found no clinically relevant differences in acid suppression between repeated doses of oral and intravenous esomeprazole. However, the pharmacokinetics of intravenous esomeprazole has not been studied extensively in children. OBJECTIVE The aim of this study was to evaluate steady-state pharmacokinetics and tolerability of repeated doses of intravenous esomeprazole in children. METHODS In this multicenter, open-label study, hospitalized patients (0-17 years of age) considered for acid suppression therapy received once-daily intravenous esomeprazole sodium for injection at 0.5 mg/kg (0-1 month of age), 1.0 mg/kg (1-11 months of age), 10 mg (1-5 years of age), 10 or 20 mg (6-11 years of age), or 20 or 40 mg (12-17 years of age) for 4 days. Children 6 to 11 years of age (inclusive) were randomized in a 1:1 ratio to receive esomeprazole 10 or 20 mg, and adolescents 12 to 17 years of age (inclusive) were randomized in a 1:1 ratio to receive esomeprazole 20 or 40 mg. Blood samples were drawn pre- and post-dose. Plasma esomeprazole was measured using reversed-phase liquid chromatography and mass spectrometry. Pharmacokinetic variables were derived using mixed-effects modeling. Adverse events (AEs) were assessed. RESULTS Fifty-nine patients were randomized and 57 received the study drug. A majority of patients were white (44 white, 5 black/African American, 3 Asian, 5 other) and male (35/57). Fifty patients were eligible for pharmacokinetic analysis, including 6 to 8 patients in each age group. Esomeprazole pharmacokinetics was dose proportional and related to weight and age. Clearance increased with increasing weight and age. The mean AUC(τ) ranged from 6.9 μmol · h/L (10 mg, 6-11 years) to 17.6 μmol · h/L (40 mg, 12-17 years). The mean C(ss,max) ranged from 3.7 μmol/L (0.5 mg/kg, 0-1 month) to 10.5 μmol/L (40 mg, 12-17 years). Thirty-one patients experienced 1 or more AEs; 6 patients experienced 1 or more treatment-unrelated serious AEs. CONCLUSIONS Intravenous esomeprazole at doses resulting in targeted AUC(τ) and C(ss,max) similar to therapeutic exposure in adults appeared to be reasonably well tolerated in this small, select pediatric population. ClinicalTrials.gov identifier: NCT00474019.
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Regulatory Experience With Physiologically Based Pharmacokinetic Modeling for Pediatric Drug Trials. Clin Pharmacol Ther 2012; 91:926-31. [DOI: 10.1038/clpt.2012.19] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Paulsson S, Eksborg S, Andersson Å, Nydert P, Grahnquist L. Acid reducing agents to neonates - lack of evidence and guidelines. J Drug Assess 2012; 1:24-9. [PMID: 27536424 PMCID: PMC4980723 DOI: 10.3109/21556660.2012.655816] [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] [Accepted: 01/05/2012] [Indexed: 11/19/2022] Open
Abstract
Objective The aim of this retrospective study was to investigate the clinical practice, i.e. the frequency of use and the treatment strategies, for acid reducing drugs to neonates in a Swedish hospital. Methods Retrospective reviews of charts and interviews with nurses at the neonatal wards of Karolinska University Hospital were performed to identify difficulties that might occur with drug administration. All patients admitted over a 2-month period were included. Main outcome measure were the number of patients treated with acid reducing drugs and the dosages. Results Nine out of 215 patients (4.2%) received an acid reducing drug. Patients treated with acid reducing drugs had significantly lower birth weight, lower gestational age and longer duration of hospitalization. Eight of the patients were treated with omeprazole. One of these patients started treatment with omeprazole but continued later on with ranitidine. One patient was exclusively treated with ranitidine. The doses of omeprazole (intravenous or oral administration) were within the range 0.16–1.26 mg/kg/day. Conclusions A wide variation in treatment regimens of acid reducing drugs is given to newborn infants. The percentage of treated children was much lower than earlier reports from the US and UK. No conclusions can be drawn as to whether the doses and dosing intervals used give sufficient acid suppression, since the effect of the therapy was not recorded. The present study is only retrospective and data are not truly comparable with other studies. Further studies are therefore warranted to evaluate effective doses and pharmacokinetics of acid reducing drugs in newborn infants.
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Affiliation(s)
- Stina Paulsson
- Karolinska Pharmacy, Karolinska University Hospital, StockholmSweden
| | - Staffan Eksborg
- Department of Women's and Children's Health, Karolinska Institutet; Karolinska Pharmacy; and Astrid Lindgren Children's Hospital, Karolinska University Hospital, StockholmSweden
| | - Åsa Andersson
- Karolinska Pharmacy and Astrid Lindgren Children's Hospital, Karolinska University Hospital, StockholmSweden
| | - Per Nydert
- Karolinska Pharmacy and Astrid Lindgren Children's Hospital, Karolinska University Hospital, StockholmSweden
| | - Lena Grahnquist
- Department of Women's and Children's Health, Karolinska Institutet and Astrid Lindgren Children's Hospital, Karolinska University Hospital, StockholmSweden
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Boussery K, De Smet J, De Cock P, Vande Velde S, Mehuys E, De Paepe P, Remon JP, Van Bocxlaer JFP, Van Winckel M. Pharmacokinetics of two formulations of omeprazole administered through a gastrostomy tube in patients with severe neurodevelopmental problems. Br J Clin Pharmacol 2011; 72:990-6. [PMID: 21658093 DOI: 10.1111/j.1365-2125.2011.04038.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS Omeprazole is often administered through a gastrostomy tube as either (i) a Multiple Unit Pellet System (MUPS®) tablet disintegrated in water (MUPS® formulation), or (ii) a suspension in 8.4% sodium bicarbonate (suspension formulation). This bioavailability study evaluates this practice in tube-fed patients with severe neurodevelopmental problems. METHODS Nonblinded, two-phase cross-over trial. RESULTS In seven of 10 patients, bioavailability was higher for the suspension formulation than for the MUPS® formulation. Median (90% confidence interval) area under the plasma concentration-time curve ratio (MUPS® over suspension) was 0.5 (0.06-2.37). CONCLUSIONS In this population, omeprazole MUPS® formulation has no apparent advantage over the more easily administered suspension formulation.
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Affiliation(s)
- Koen Boussery
- Laboratory of Medical Biochemistry and Clinical Analysis, Ghent University, Gent, Belgium.
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Abstract
During developmental age, differences in pharmacodynamic reactions to several drugs may reflect polymorphisms of genes encoding drug-transporting proteins, receptors, drug targets, and gene products, whose disturbed activity sometimes plays an important role in certain diseases. Administration of drugs with a narrow therapeutic index may quite easily be associated with changes in pharmacokinetics and development of adverse drug reactions, which occasionally may cause fatalities. In such cases, polypragmasy and resulting drug interactions may enhance effects of changes in drug-metabolizing enzymes' activities. Phenotyping and genotyping of patients slowly are finding their place in some therapeutic regimens used in clinical gastroenterology and hepatology. At present, some assays to measure, for example, thiopurine S-methyltransferase activity are already commercially available. Polymorphisms of CYP450 enzymes, interleukins, and altered gene expression play an important role in some patients' various gastrointestinal tract and liver diseases. Herbal drugs also affect proinflammatory and antiinflammatory cytokine and nitric oxide balance in the body. Therapeutic use of recombined proteins, such as infliximab, natalizumab, onercept, humanized antibody to integrin α-4 β-7, or IFN-β in some large-bowel diseases increased therapeutic efficacy. IFN-α used in the patients with chronic hepatitis C improved cellular immunity in these subjects and exerted antiviral activity. Practical application of progress in pharmacogenetics, pharmacokinetics, pharmacodynamics, and use of bioproducts in novel therapeutic regimens has opened therapeutic frontiers and increased clinical safety.
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Vet NJ, de Hoog M, Tibboel D, de Wildt SN. The effect of inflammation on drug metabolism: a focus on pediatrics. Drug Discov Today 2011; 16:435-42. [PMID: 21376135 DOI: 10.1016/j.drudis.2011.02.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 01/11/2011] [Accepted: 02/22/2011] [Indexed: 11/28/2022]
Affiliation(s)
- Nienke J Vet
- Intensive Care, Erasmus MC - Sophia Children's Hospital, Dr. Molewaterplein 60, 3015 GJ Rotterdam, The Netherlands.
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Higginbotham TW. Effectiveness and Safety of Proton Pump Inhibitors in Infantile Gastroesophageal Reflux Disease. Ann Pharmacother 2010; 44:572-6. [DOI: 10.1345/aph.1m519] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Objective: To evaluate the efficacy and safety of proton pump inhibitors (PPIs) in the treatment of gastroesophageal reflux disease (GERD) in infants <1 year of age. Data Sources: A literature search was conducted through PubMed (up to December 2009), International Pharmaceutical Abstracts (1970–December 2009), and The Cochrane Library (up to December 2009) using combinations of the following key search terms: proton pump inhibitor, GERD, infant, children, pediatric, omeprazole, rabeprazole, lansoprazole, esomeprazole, and pantoprazole. Reference citations from identified articles were also reviewed. Study Selection And Data Extraction: All double-blind, placebc-controlled trials published in English that evaluated the safety and efficacy of PPIs in infants with GERD were included in this review. Trials involving children older than 12 months were not included. Data Synthesis: GERD is a source of pain and discomfort in adults; yet, in infants, symptoms that are thought to be indicative of painful stimuli have no clear cause-and-effect relationship with infant GERD. PPIs are beneficial in relieving symptoms of GERD in the adult population, but their usefulness in decreasing GERD-associated behaviors in infants is still questionable, despite a large increase in PPI prescribing for children <1 year of age. In all studies reviewed, infants treated with PPIs did not experience a significant decrease in behaviors perceived to be caused by GERD. The largest placebo-controlled trial to date found that rates of adverse events were increased in the PPI group compared with the placebo group, whereas the other trials reviewed reported no difference in adverse effects with the use of PPIs. Conclusions: Clinical trials reveal that PPI therapy is not an effective treatment for common infant GERD-associated symptoms. Evidence supporting safety of PPI use in infants is conflicting, and more large-scale, randomized, placebo-controlled trials are necessary to better establish the role of PPIs in infant GERD.
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Affiliation(s)
- Tanner W Higginbotham
- Idaho Drug Information Service, College of Pharmacy, Idaho State University, 921 S. 8th Ave., Stop 8092, Pocatello, ID 83209
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Solana MJ, López-Herce J. Pharmacokinetics of intravenous omeprazole in critically ill paediatric patients. Eur J Clin Pharmacol 2009; 66:323-30. [PMID: 20041322 DOI: 10.1007/s00228-009-0774-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Accepted: 12/02/2009] [Indexed: 11/25/2022]
Abstract
The proton pump inhibitors are first-line drugs for the treatment of a number of gastrointestinal diseases. These drugs have a good safety profile, making it possible to use them in paediatric patients. Although their pharmacokinetics in children has not been extensively studied, research performed suggests that the dose used should be varied as a function of age, as this factor affects the drug's metabolism. Proton pump inhibitors can be used in critically ill children for the prophylaxis and treatment of gastrointestinal haemorrhage, although there is still little experience with this. The most widely used proton pump inhibitor at the present time is omeprazole. As there are specific characteristics of these patients that could alter the pharmacokinetics of the drugs, studies need to be performed to determine the most suitable dose and dosage interval.
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Pettersen G, Mouksassi MS, Théorêt Y, Labbé L, Faure C, Nguyen B, Litalien C. Population pharmacokinetics of intravenous pantoprazole in paediatric intensive care patients. Br J Clin Pharmacol 2008; 67:216-27. [PMID: 19173681 DOI: 10.1111/j.1365-2125.2008.03328.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT The use of intravenous pantoprazole, a proton pump inhibitor, has been increasing in the paediatric intensive care unit. Despite this increased use, data on the disposition of intravenous pantoprazole in paediatric intensive care patients are very scarce. WHAT THIS STUDY ADDS Our population approach has determined the pharmacokinetic parameters of intravenous pantoprazole in paediatric intensive care patients and the relative importance of factors influencing its disposition. Pantoprazole clearance was significantly influenced by developmental changes and by the presence of systemic inflammatory syndrome, hepatic dysfunction and CYP2C19 inhibitors. AIMS To characterize the pharmacokinetics of intravenous pantoprazole in a paediatric intensive care population and to determine the influence of demographic factors, systemic inflammatory response syndrome (SIRS), hepatic dysfunction and concomitantly used CYP2C19 inducers and inhibitors on the drug's pharmacokinetics. METHODS A total of 156 pantoprazole concentration measurements from 20 patients (10 days to 16.4 years of age) at risk for or with upper gastrointestinal bleeding, who received pantoprazole doses ranging from 19.9 to 140.6 mg/1.73 m(2)/day, were analysed using a population pharmacokinetic approach (nonmem program). RESULTS The best structural model for pantoprazole was a two-compartment model with zero order infusion and first-order elimination. Body weight, SIRS, age, hepatic dysfunction and presence of CYP2C19 inhibitors were significant covariates affecting clearance (CL), accounting for 75% of interindividual variability. Only body weight significantly influenced central volume of distribution (V(c)). In the final population model, the estimated CL and V(c) were 5.28 l h(-1) and 2.22 l, respectively, for a typical 5-year-old child weighing 20 kg. Pantoprazole CL increased with weight and age, whereas the presence of SIRS, CYP2C19 inhibitors and hepatic dysfunction, when present separately, significantly decreased pantoprazole CL by 62.3, 65.8 and 50.5%, respectively. For patients aged between 6 months and 5 years without SIRS, CYP2C19 inhibitor or hepatic dysfunction, the predicted pantoprazole CL is faster than that reported in adults. CONCLUSION These results provide important information for physicians regarding selection of a starting dose and dosing regimens of pantoprazole for paediatric intensive care patients based on factors frequently encountered in this population.
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Affiliation(s)
- Géraldine Pettersen
- Clinical Pharmacology Unit, Department of Paediatrics, Divisions of Paediatric Critical Care, Centre Hospitalier Universitaire Sainte-Justine, 3175 chemin de la Côte Sainte-Catherine, Montréal, Québec, Canada
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Bishop J, Furman M, Thomson M. Omeprazole for gastroesophageal reflux disease in the first 2 years of life: a dose-finding study with dual-channel pH monitoring. J Pediatr Gastroenterol Nutr 2007; 45:50-5. [PMID: 17592364 DOI: 10.1097/mpg.0b013e318049cbcc] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND AIM Gastroesophageal reflux occurs in the majority of infants, with severity ranging from asymptomatic to severe esophagitis and failure to thrive. Omeprazole is recognized as a safe and effective treatment of gastroesophageal reflux in older children, at an initial dosage of 0.7 mg x kg(-1) x day(-1). To our knowledge, no dose-finding studies have been carried out in children under 2 years of age. The aim of the present study was to prospectively determine the dosage of omeprazole required to treat symptomatic gastroesophageal reflux in children younger than 2 years. PATIENTS AND METHODS Children under 2 years with clinical suspicion of gastroesophageal reflux underwent 24-hour dual-channel intraesophageal/gastric pH monitoring. A reflux index above 10% in children under 1 year and above 6% in children older than 1 year was deemed significant. Treatment with omeprazole at an initial dosage of 0.7 mg x kg(-1) x day(-1) (in 2 divided doses) was followed by dual-channel pH study after 14 days. The dosage was increased in increments of 0.7 mg x kg(-1) x day(-1), and pH studies were repeated until the gastroesophageal reflux was controlled. RESULTS Ten children (5 male, 5 female), mean age 7.75 months (range, 1.25-20 months), were investigated. The initial median reflux index was 18.5% (range, 6.5%-56.3%). Follow-up median reflux index was improved at 1.6% (0.1%-8.1%) (P < 0.05). The median dosage required was 1.05 mg x kg(-1) x day(-1). Four children required 1.4 mg x kg(-1) x day(-1), and 1 required 2.8 mg x kg(-1) x day(-1). Corrected reflux index improved from 34.8% (16.8%-90.8%) to 20.1% (0.4%-100%) but did not achieve statistical significance. There were no serious complications or side effects. CONCLUSIONS Omeprazole is an effective treatment for gastroesophageal reflux in children younger than 2 years. The majority respond to a dosage of 0.7 mg x kg(-1) x day(-1), but increased dosages up to 2.8 mg x kg(-1) x day(-1) may be required.
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Tsou VM, Baker R, Book L, Hammo AH, Soffer EF, Wang W, Comer GM. Multicenter, randomized, double-blind study comparing 20 and 40 mg of pantoprazole for symptom relief in adolescents (12 to 16 years of age) with gastroesophageal reflux disease (GERD). Clin Pediatr (Phila) 2006; 45:741-9. [PMID: 16968960 DOI: 10.1177/0009922806292792] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
An age-appropriate questionnaire (GASP-Q) was used to assess the frequency and severity of the gastroesophageal reflux disease (GERD) symptoms: abdominal/belly pain, chest pain/heartburn, pain after eating, nausea, burping/belching, vomiting/regurgitation, choking when eating, and difficulty swallowing, in adolescents age 12 to 16 years. The primary objective was to compare the mean composite symptom score (CSS) at week 8 with baseline after treatment with 20 or 40 mg of pantoprazole. Statistically significant (p < 0.001) improvement in CSS occurred in both groups. Safety was comparable between the 2 groups. Pantoprazole was safe, well tolerated, and effective in reducing symptoms of GERD in adolescents.
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Affiliation(s)
- V Marc Tsou
- Children's Hospital of The King's Daughter, Norfolk, VA, USA
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18
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Abstract
BACKGROUND AND OBJECTIVE Considerable ethnic differences have been reported in the incidence of the poor metaboliser (PM) genotype of cytochrome P450 (CYP) 2C19. The frequency of this genotype was found to be much higher in Oriental persons (13-23%) than in American or European populations (3-5%). There are, however, no valid data published for Arabic subjects. The present study was conducted to evaluate pharmacokinetic parameters of omeprazole after a single dose in healthy Jordanian Arabic subjects and to compare the results with data published for other populations. METHODS Seventy-four healthy male Jordanian Arabic volunteers contributed to the study, which was performed at Al Essra Hospital in Amman, Jordan. After an overnight fast, omeprazole was administered as a single Losec 20mg capsule. A total of 20 blood samples were collected over a 10-hour period after administration. Omeprazole pharmacokinetic parameters were determined from the plasma concentration-time profiles using the WinNonlin software. Kolmogorov-Smirnov's test and probit plots of omeprazole area under the plasma concentration-time curve (AUC) data were used to analyse the frequency distribution of phenotypic data. RESULTS The mean pharmacokinetic parameters and their corresponding coefficient of variation (CV%) for peak plasma concentration (Cmax), AUC from time zero to infinity (AUCinfinity), time to reach Cmax (tmax), apparent oral clearance (CL/F) and elimination half-life (t(1/2)) were 314.96 ng/mL (56%), 923.2 ng . h/mL (108.6%), 2.1h (44%), 0.66 L/h/kg (92%) and 1.5 h (56.6%), respectively. Interindividual differences in the current study were high for all pharmacokinetic parameters, yet comparable to CVs reported in nonphenotyped subjects identified within other ethnic groups (40.3-159% for AUC and 39-48.2% for Cmax). The frequency distribution of all parameters, particularly the AUC, was shown to be trimodal. This has proposed the presence of three distinct phenotypes, designated as extensive metabolisers (EMs), slow-extensive metabolisers (SEMs), and PMs, with corresponding frequency of 36.5%, 39.2% and 24.3%, respectively. After stratification, the relative mean AUCs of omeprazole in EMs, SEMs and PMs were 1 : 2.7 : 9.3 (all p < 0.001). Accordingly, the CL/F of omeprazole showed a ratio of 9.8 : 3.6 : 1 for three phenotype groups, respectively. For other pharmacokinetic parameters including Cmax, t1/2, AUC normalised for bodyweight (AUCN), Cmax/dose and AUC/dose, there were also significant differences between the three groups. CONCLUSIONS The current pharmacokinetic study revealed that the majority of the Jordanian Arabics seemed to be more properly classified within the EM phenotype. More specifically, the observed metabolic rates of heterozygous and homozygous Jordanian Arabic EMs were more comparable to those of Caucasian EMs than Oriental EMs. Consequently, higher dosage requirements can be expected among most of the Jordanian Arabics. Yet, the incidence of PMs is significant and they seemed to exhibit a similar pharmacokinetic pattern to Chinese PMs in terms of long-term exposure (clearance and AUC) as well as short-term exposure (Cmax) parameters, after adjustment for dose and bodyweight. Therefore, further clinical application of CYP2C19 polymorphism is anticipated in Jordanian Arabic mixed population, particularly if long-term use of omeprazole is intended.
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19
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Abstract
Gastro-oesophageal reflux (GOR) and gastro-oesophageal reflux disease (GORD) occur frequently during the first months of life. Gastro-oesophageal reflux may be a primary gastro-intestinal motility disorder, but it may also be secondary to other conditions such as cow's milk protein allergy. Objective diagnosis can be difficult because there may be absence of correlation between history, results of pH monitoring and histology. Severe GORD may cause minor symptoms, and minor GOR may cause severe symptoms. Several different therapeutic interventions exist. Simply stated, thickened formula reduces regurgitation and alginates and proton pump inhibitors can be used to decrease acid GOR, depending on the severity of the GORD. Efficacy data of prokinetic drugs are either lacking or disappointing. Regarding side-effects, interest has been focused on cisapride, although other molecules have similar effects. Long-term side-effects such as the nutritional consequence of therapeutic management have been insufficiently studied, especially for the acid-reducing molecules.
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Affiliation(s)
- Yvan Vandenplas
- Academisch Ziekenhuis Vrije Universiteit Brussel, Brussels, Belgium.
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20
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Abstract
The use of proton pump inhibitors (PPIs) has become widespread in children and infants for the management of paediatric acid-related disease. Pharmacokinetic profiles of only omeprazole and lansoprazole have been well characterised in children over 2 years of age with acid-related diseases. Few data have been recently published regarding the pharmacokinetics of pantoprazole in children, and none are available for rabeprazole or esomeprazole. The metabolism of PPI enantiomers has never been studied in the paediatric population. A one-compartment model best describes the pharmacokinetic behaviour of omeprazole, lansoprazole and pantoprazole in children, with important interindividual variability for each pharmacokinetic parameter. Like adults, PPIs are rapidly absorbed in children following oral administration; the mean time to reach maximum plasma concentration varies from 1 to 3 hours. Since these agents are acid labile, their oral formulations consist of capsules containing enteric-coated granules. No liquid formulation is available for any of the PPIs. Thus, for those patients unable to swallow capsules, extemporaneous liquid preparations for omeprazole and lansoprazole have been reported; however, neither the absolute nor the relative bioavailabilities of these oral formulations have been studied in children. Intravenous formulations are available for omeprazole (in Europe), lansoprazole and pantoprazole. PPIs are rapidly metabolised in children, with short elimination half-lives of around 1 hour, similar to that reported for adults. All PPIs are extensively metabolised by the liver, primarily by cytochrome P450 (CYP) isoforms CYP2C19 and CYP3A4, to inactive metabolites, with little unchanged drug excreted in the urine. Similar to that seen in adults, the absolute bioavailability of omeprazole increases with repeated dosing in children; this phenomenon is thought to be due to a combination of decreased first-pass elimination and reduced systemic clearance. The apparent clearance (CL/F) of omeprazole, lansoprazole and pantoprazole appears to be faster for children than for adults. A higher metabolic capacity in children as well as differences in the extent of PPI bioavailability are most likely responsible for this finding. This may partly account for the need in children for variable and sometimes considerably greater doses of PPIs, on a per kilogram basis, than for adults to achieve similar plasma concentrations. Furthermore, no studies have been able to demonstrate a statistically significant correlation between age and pharmacokinetic parameters among children. Despite the small number of very young infants studied, there is some evidence for reduced PPI metabolism in newborns. The limited paediatric data regarding the impact of CYP2C19 genetic polymorphism on PPI metabolism are similar to those reported for adults, with poor metabolisers having 6- to 10-fold higher area under the concentration-time curve values compared with extensive metabolisers. Finally, because a pharmacokinetic/pharmacodynamic relationship exists for PPIs, the significant interindividual variability in their disposition may partly explain the wide range of therapeutic doses used in children. Further studies are needed to better define the pharmacokinetics of PPIs in children <2 years of age.
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21
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Carcelén Andrés J, Barroso Péez C, Fábrega Bosacoma C, Feal Cortizas B, Gallego Lago V, Hidalgo Albert E, Pozas del Río MT, Revert Molina-Niñirola A, Valderde Molina E, Wood Wood MA. Inhibidores de la bomba de protones en pediatría. FARMACIA HOSPITALARIA 2005; 29:43-54. [PMID: 15773802 DOI: 10.1016/s1130-6343(05)73635-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
In last years the use in the pediatric area of proton pump inhibitors (omeprazole, lansoprazole, pantoprazole, rabeprazole and esomeprazole) is more often, nevertheless the clinical trials carried out are poor. The aim of this work is to analyse the bibliography published about this kind of drugs in children and to make a revision of its use in the last seven years. More studies with omeprazole and lansoprazole have been developed, to be exact omeprazole and lansoprazole is present in 122 bibliographic appointments and 34 for lansoprazole, which include studies that demonstrate a good tolerance and efficacy. The remaining proton pump inhibitors count with very few studies. The main therapeutic indications were the eradication of Helicobacter pylori, gastroesophageal reflux disease and esophagitis. The number of patients included in the reviewed studies is quite heterogeneous, from 8 to 122 and the age range between 8 days and 17 years. On the other hand, it could be highlighted the non-existence of formulations adapted to the pediatric population and the difficulty of administration specially in the youngest patients. As in many other drugs, it would be necessary to carry out clinical trials in order to determinate the pharmacologic parameters at difference ages, which will allow a safe and effective administration, and its authorization by all Health Authorities.
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22
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Kearns GL, Andersson T, James LP, Gaedigk A, Kraynak RA, Abdel-Rahman SM, Ramabadran K, van den Anker JN. Omeprazole disposition in children following single-dose administration. J Clin Pharmacol 2003; 43:840-8. [PMID: 12953341 DOI: 10.1177/0091270003256122] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
UNLABELLED Omeprazole is frequently used to treat gastroesophageal reflux in infants and children despite the lack of age-specific pharmacokinetic and dosing information in the approved product labeling. To address this challenge, the authors examined the potential influence of development and cytochrome P450 2C19 (CYP2C19) genotype on omeprazole disposition by conducting two pharmacokinetic (PK) studies in children and adolescents (ages 2-16 years) after a single oral 10- or 20-mg dose of the drug. Plasma omeprazole concentrations were determined by HPLC-MS from seven plasma samples obtained over a 6-hour postdose period. Pharmacokinetic parameters were determined by noncompartmental methods. Subjects were genotyped for CYP2C19 by PCR-RFLP. Data were available from 37 patients (19 female), 10 of whom were < or = 5 years of age. No drug-associated adverse events were observed. The numbers of functional CYP2C19 alleles per subject in the cohort were 2 (n = 25), 1 (n = 11), and 0 (n = 1). Pharmacokinetic parameters (mean +/- SD, range) were as follows: tmax (2.1 +/- 1.2, 1-6 h), Cmax (331.1 +/- 333.6, 20.8-885.8 ng/mL), AUC0-->infinity (809.5 +/- 893.8, 236.9-1330.9 ng/mL.h), t1/2 (0.98 +/- 0.22, 0.7-1.4 h), and CL/F (1.8 +/- 1.4, 0.3-5.8 L/h/kg). Comparison of mean AUC0-->infinity values normalized for dose (i.e., per 1 mg/kg) between subjects with one versus two functional CYP2C19 alleles revealed no statistically significant difference. In addition, the CL/F and apparent elimination rate constant (lambda z) for omeprazole were not significantly different for subjects with one versus two functional CYP2C19 alleles. No association between age and CL/F, t1/2, or lambda z was observed. The range of t1/2 values for omeprazole was similar to those reported in adults (1-1.5 h). CONCLUSIONS (1) in children ages 2 to 16 years receiving 10 or 20 mg of omeprazole as a single oral dose, the PK are quite comparable to values reported for adults, and (2) in pediatric patients who are CYP2C19 extensive metabolizers, there was no association between genotype and the pharmacokinetics of omeprazole.
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Affiliation(s)
- Gregory L Kearns
- Departments of Pediatrics and Pharmacology, University of Missouri, Division of Pediatric Clinical Pharmacology and Medical Toxicology, Children's Mercy Hospitals and Clinics, Kansas City, Missouri, USA
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23
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Abstract
Proton pump inhibitors (PPIs) belong to a group of chemically related compounds whose primary function is the inhibition of acid production in the final common metabolic pathway of gastric parietal cells. PPIs are highly selective and effective in their action and have few short- or long-term adverse effects. These pharmacologic features have made the development of PPIs the most significant advancement in the management of acid peptic related disorders in the last two decades. There are numerous published adult studies that describe the pharmacology, efficacy and safety of these anti-secretory agents; however, in the pediatric population, there are very few comparable studies, particularly multicenter studies with significant patient enrollment. In preparing this article, our aim was to perform a comprehensive review of the literature on the clinical pharmacology and use of PPIs in the pediatric population, and to briefly review some recent articles. Relevant literature was identified by performing MEDLINE/Pubmed searches from January 1990 to December 2001. Combinations of the following search terms were use to analyze these databases: proton pump inhibitor, children, pediatrics, gastroesophageal reflux disease (GERD), esophagitis, intestinal metaplasia, Helicobacter pylori, omeprazole, lansoprazole, pantoprazole, rabeprazole, esomeprazole, and safety. Abstracts from the 14th annual conference of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN) 2001, and the Disease and Digestive Week 2001, were also included in the review. All pediatric studies reviewed were limited to either omeprazole or lansoprazole. The dosage range used for the management of GERD and related disorders with lansoprazole was 0.73-1.66 mg/kg/day (maximum 30 mg/day). The dosage range for GERD management using omeprazole was 0.3-3.5 mg/kg (maximum 80 mg/day). The dosage range for omeprazole used for H. pylori was 0.5-1.5 mg/kg/day, with a maximum dosage of 40 mg/day, and lansoprazole-containing regimens for H. pylori eradication used dosages ranging from 0.6-1.2 mg/kg/day, with a maximum dosage of 30 mg/day. Few severe adverse events were reported with the use of either drug. Eradication rates for H. pylori were 56-87% for lansoprazole-based triple therapy, and 75-94% for omeprazole-based eradication regimens. To date, there are no published controlled trials of sufficient power comparing the efficacy of the five commercially available PPIs in children, for a variety of acid peptic diseases. Studies suggest that PPIs are highly effective for the management of GERD and related disorders, and are a critically needed component of triple therapy to eradicate H. pylori. PPIs have a very good tolerability profile in adults and children, but long-term tolerability studies are needed, particularly in the pediatric population. Multicenter studies are critically needed to evaluate the second-generation PPIs, to compare PPI efficacy to each other, and to assess the importance of developmental and genetic pharmacology of these drugs in children with acid-peptic disease.
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Affiliation(s)
- Troy E Gibbons
- Department of Pediatrics, Division of Pediatric Gastroenterology and Nutrition, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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24
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Affiliation(s)
- Michele Scaillon
- Department of Gastroenterology, Queen Fabiola Children's Hospital, Free University of Brussels, Belgium
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