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Xiong Y, Zhu S, Zhao H, Li J, Li Y, Gong T, Tao Y, Hu J, Wang H, Jiang X. An electrochemical sensor based on CS-MWCNT and AuNPs for the detection of mycophenolic acid in plasma. Anal Biochem 2023; 677:115265. [PMID: 37499894 DOI: 10.1016/j.ab.2023.115265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 07/20/2023] [Accepted: 07/24/2023] [Indexed: 07/29/2023]
Abstract
For patients receiving organ transplants, monitoring the blood concentration of MPA can provide timely information on whether MPA has reached the effective therapeutic window to better function while reducing the incidence of rejection or adverse reactions. In this study, an electrochemical sensor for the detection of MPA was built using a nanocomposite made of CS-MWCNT and AuNPs. At the same time, the high performance liquid phase (HPLC) method for MPA was established and compared with this sensor. The surface morphology, structure, and roughness of the material on the electrode were characterized by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), and atomic force microscopy (AFM). In addition, the electrochemical behavior of the modified electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The standard curve was obtained in blank plasma, not pure buffer solution. The peak current was linearly related to the MPA concentration in the linear range of 0.001-0.1 mM with a detection limit of 0.05 μM and good anti-interference ability. Moreover, the sensor was employed with success for the determination of MPA in rat plasma with good recovery. The electrochemical sensor presented here is eco-friendly, and sensitive, and offers a great possibility for practical applicability.
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Affiliation(s)
- Yan Xiong
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China
| | - Shu Zhu
- Laboratory of Pharmacy and Chemistry, Lab Teaching & Management Center, Chongqing Medical University, Chongqing, 400016, China
| | - Hua Zhao
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China
| | - Jin Li
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China; Department of Pharmacy, Children's Hospital Affiliated to Chongqing Medical University, Chongqing, 400014, China
| | - Yanting Li
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China
| | - Tao Gong
- Nanchong Key Laboratory of Individualized Drug Therapy, Nanchong Central Hospital, Nanchong, 637000, Sichuan, China
| | - Yanru Tao
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China
| | - Jiangling Hu
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China
| | - Hongmei Wang
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China; Fu an Pharmaceutical Group Chongqing Lybon Pharm-Tech Co.,Ltd, Chongqing, 401121, China
| | - Xinhui Jiang
- Chongqing Research Center for Pharmaceutical Engineering, School of Pharmacy, Chongqing Medical University, Chongqing, 400016, China.
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2
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Rong Y, Wichart J, Hamiwka L, Kiang TKL. Significant Effects of Renal Function on Mycophenolic Acid Total Clearance in Pediatric Kidney Transplant Recipients with Population Pharmacokinetic Modeling. Clin Pharmacokinet 2023; 62:1289-1303. [PMID: 37493886 DOI: 10.1007/s40262-023-01280-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/21/2023] [Indexed: 07/27/2023]
Abstract
BACKGROUND AND OBJECTIVES Mycophenolic acid (MPA) is an immunosuppressant commonly prescribed in pediatric kidney transplantation to prevent graft rejection. Large variabilities in MPA plasma exposures have been observed in this population, which could result in severe adverse effects. The majority of the MPA pharmacokinetic data have been reported in adult populations, whereas information in pediatric patients is still very limited. The objective of this study was to establish a novel, nonlinear mixed-effects model for MPA and investigate the clinical variables affecting MPA population pharmacokinetics in pediatric kidney transplant recipients. METHODS Data were collected retrospectively from pediatric kidney transplant patients (≤ 18 years when MPA concentrations were initially collected; on oral administration of mycophenolate mofetil) in Calgary, Alberta, Canada. Nonlinear mixed-effect modeling was conducted using stochastic approximation expectation-maximization in Monolix 2021R2 (Lixoft SAS, France) to determine population pharmacokinetic estimates, interindividual variabilities, and interoccasional variabilities. Covariate models were constructed using the Model Proposal function in Monolix in conjunction with a systematic stepwise inclusion/elimination protocol. The best model was selected based on objective function values, relative standard errors, goodness-of-fit plots, prediction-corrected visual predictive checks, and numerical predictive checks. RESULTS A total of 50 pediatric kidney transplant patients (25 female) with 219 MPA plasma concentration-time profiles were included. The average age (± standard deviation) and posttransplant time for the sample population were 12.8 ± 4.8 years and 762 ± 1160 days, respectively. The majority of study subjects (i.e., > 85% based on all occasions) were co-administered tacrolimus. A two-compartment, first-order absorption with lag time and linear elimination structural model with lognormal distributed proportional residual errors best described the MPA concentration-time data. The absorption rate constant (2.52 h-1 or 0.042 min-1), lag time (0.166 h or 9.96 min), volumes of distributions of the central (22.8 L) and peripheral (216 L) compartments, and intercompartment clearance (17.6 L h-1 or 0.293 L min-1) were consistent with literature values; whereas total MPA clearance (0.72 L h-1 or 0.012 L min-1) was relatively reduced, likely due to the general lack of cyclosporine interactions and the stabilized graft functions from significantly longer posttransplant time in our sample population. Of the clinical variables tested, only estimated glomerular filtration rate (eGFR) was identified a significant covariate affecting total MPA clearance with a positive, exponential relationship. The final population pharmacokinetic model was successfully evaluated/validated using a variety of complementary methods. CONCLUSION We have successfully constructed and validated a novel population pharmacokinetic model of MPA in pediatric kidney transplant patients. A positive, nonlinear relationship between eGFR and total MPA clearance identified in our model is likely attributed to multiple concurrent mechanisms, which warrant further systematic investigations.
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Affiliation(s)
- Yan Rong
- Faculty of Pharmacy and Pharmaceutical Sciences, Katz Group Centre for Pharmacy and Health Research, University of Alberta, Room 3-142D, 11361-87 Avenue, Edmonton, AB, T6G 2E1, Canada
| | - Jenny Wichart
- Alberta Health Services, Pharmacy Services, Calgary, AB, Canada
| | - Lorraine Hamiwka
- Department of Pediatrics, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Tony K L Kiang
- Faculty of Pharmacy and Pharmaceutical Sciences, Katz Group Centre for Pharmacy and Health Research, University of Alberta, Room 3-142D, 11361-87 Avenue, Edmonton, AB, T6G 2E1, Canada.
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3
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Taha K, Sharma A, Kroeker K, Ross C, Carleton B, Wishart D, Medeiros M, Blydt-Hansen TD. Noninvasive testing for mycophenolate exposure in children with renal transplant using urinary metabolomics. Pediatr Transplant 2022; 27:e14460. [PMID: 36582125 DOI: 10.1111/petr.14460] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 09/11/2022] [Accepted: 11/18/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Despite the common use of mycophenolate in pediatric renal transplantation, lack of effective therapeuic drug monitoring increases uncertainty over optimal drug exposure and risk for adverse reactions. This study aims to develop a novel urine test to estimate MPA exposure based using metabolomics. METHODS Urine samples obtained on the same day of MPA pharmacokinetic testing from two prospective cohorts of pediatric kidney transplant recipients were assayed for 133 unique metabolites by mass spectrometry. Partial least squares (PLS) discriminate analysis was used to develop a top 10 urinary metabolite classifier that estimates MPA exposure. An independent cohort was used to test pharmacodynamic validity for allograft inflammation (urinary CXCL10 levels) and eGFR ratio (12mo/1mo eGFR) at 1 year. RESULTS Fifty-two urine samples from separate children (36.5% female, 12.0 ± 5.3 years at transplant) were evaluated at 1.6 ± 2.5 years post-transplant. Using all detected metabolites (n = 90), the classifier exhibited strong association with MPA AUC by principal component regression (r = 0.56, p < .001) and PLS (r = 0.75, p < .001). A practical classifier (top 10 metabolites; r = 0.64, p < .001) retained similar accuracy after cross-validation (LOOCV; r = 0.52, p < .001). When applied to an independent cohort (n = 97 patients, 1053 samples), estimated mean MPA exposure over Year 1 was inversely associated with mean urinary CXCL10:Cr (r = -0.28, 95% CI -0.45, -0.08) and exhibited a trend for association with eGFR ratio (r = 0.35, p = .07), over the same time period. CONCLUSIONS This urinary metabolite classifier can estimate MPA exposure and correlates with allograft inflammation. Future studies with larger samples are required to validate and evaluate its clinical application.
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Affiliation(s)
- Khalid Taha
- Department of Pediatrics, University of British Columbia, BC Children's Hospital Vancouver, Vancouver, British Columbia, Canada
| | - Atul Sharma
- Department of Pediatrics and Child Health, University of Manitoba, Children's Hospital at Health Sciences Center, Winnipeg, Manitoba, Canada
| | - Kristine Kroeker
- Centre for Healthcare Innovation, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Colin Ross
- Faculty of Pharmaceutical Sciences, University of British Columbia, BC Children's Hospital Vancouver, Vancouver, British Columbia, Canada
| | - Bruce Carleton
- Department of Pediatrics, University of British Columbia, BC Children's Hospital Vancouver, Vancouver, British Columbia, Canada
| | - David Wishart
- Departments of Computing Science and Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Mara Medeiros
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Tom D Blydt-Hansen
- Department of Pediatrics, University of British Columbia, BC Children's Hospital Vancouver, Vancouver, British Columbia, Canada
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4
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Catić‐Đorđević A, Stefanović N, Pavlović I, Pavlović D, Živanović S, Kundalić A, Veličković‐Radovanović R, Mitić B. Utility of salivary mycophenolic acid concentration monitoring: Modeling and Monte Carlo validation approach. Pharmacol Res Perspect 2022; 10:e01034. [PMID: 36440680 PMCID: PMC9703583 DOI: 10.1002/prp2.1034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/20/2022] [Accepted: 11/06/2022] [Indexed: 11/29/2022] Open
Abstract
The results of the previous studies demonstrated an association between mycophenolic acid (MPA) exposure, serum albumin level (ALB), and adverse effects in kidney transplant patients. The aim was the identification of mathematical correlation and association between both, total and unbound MPA concentration in relation to ALB, body mass (BM), age and estimated glomerular filtration rate (eGFR) in stable kidney transplant recipients. Furthermore, investigation was conducted with the aim to clarify the role of salivary concentration (CSAL ) of MPA in adverse effect profile. In order to analyze the association between total and salivary concentration of MPA in relation to ALB, BM, age and eGFR, a least squares method for determining the correlation between these parameters was performed. In addition, derived mathematical model based on experimental data can also be performed and simulated through the Monte Carlo (MC) approach. Adverse effects were grouped according to the nature of symptoms and scored by a previously published validated system. Numerically calculated values of CSAL from the models [CSAL = f(ALB, BM, age, eGFR, CP ) = a00 + a10 *(ALB, BM, age, eGFR) + a01 *CP ] were then compared with those from validation set of patients, where the best fitting model was for ALB [CSAL = 54.96-1.64*ALB +13.4*CP ]. Adverse effects estimation showed the difference in esthetic score, positively correlated with CSAL in the lower ALB group (145.41 ± 219.02 vs. 354.08 ± 262.19; with statistical significance p = .014) and almost significant for gastrointestinal score (167.69 ± 174.79 vs. 347.55 ± 320.95; p = .247). The study showed that CSAL MPA may contribute to management of adverse effects, but these findings require confirmation of clinical utility.
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Affiliation(s)
| | - Nikola Stefanović
- Faculty of Medicine, Department of PharmacyUniversity of NisNisSerbia
| | - Ivan Pavlović
- Faculty of Mechanical EngineeringUniversity of NisNisSerbia
| | - Dragana Pavlović
- Faculty of Medicine, Department of PharmacyUniversity of NisNisSerbia
| | - Slavoljub Živanović
- Faculty of Medicine, Research Center for BiomedicineUniversity of NisNisSerbia
| | - Ana Kundalić
- Faculty of Medicine, Department of PharmacyUniversity of NisNisSerbia
| | | | - Branka Mitić
- Faculty of MedicineUniversity of NisNisSerbia
- Clinic of NephrologyUniversity Clinical Center NisNisSerbia
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5
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Liu Y, Zhang H, Li J, Liu L, Wu C, Fu Q, Huang M, Chen X, Wang C, Chen P. Pharmacokinetics of free and total mycophenolic acid in paediatric and adult renal transplant recipients: Exploratory analysis of the effects of clinical factors and gene variants. Basic Clin Pharmacol Toxicol 2022; 131:60-73. [PMID: 35567285 DOI: 10.1111/bcpt.13743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 04/20/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022]
Abstract
Clinical and genetic influencing factors on free fraction of mycophenolic acid (MPA) have rarely been discussed. The present study investigated whether the clinical and genetic factors could explain the variability in the pharmacokinetics of free MPA (fMPA) and total MPA (tMPA) in Chinese paediatric and adult renal transplant recipients. Twenty-eight paediatric and 31 adult patients were enrolled, and the concentrations of tMPA and fMPA were determined at 0 h (predose) and 0.5, 1, 1.5, 2, 4, 5, 8, 9, 10 and 12 h after mycophenolate mofetil administration. Genetic polymorphisms of UGTs (rs671448, rs1042597, rs2741049, rs62298861, rs7439366, rs12233719) and ABCC2 (rs717620) were simultaneously determined. The clinical and genetic data were analysed and reported. tMPA and fMPA concentrations adjusted for dose per body weight were consistently higher in adults than in paediatric patients. In the paediatric group, only albumin and time after transplantation correlated significantly with the MPA-free fraction variation, which could explain 32.4% of the variability. Besides, ABCC2 polymorphism, albumin and time after transplantation correlated significantly with the MPA-free fraction variation in adults, which could explain 56.9% of the variability. The influencing factors in the paediatric group are different from those in adults, which may be due to age-related transporter expression.
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Affiliation(s)
- Yan Liu
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Pharmacy, First hospital of Nanchang, Nanchang, China.,Institule of Clinical Pharmacology, School of Pharmaceutical sciences, Sun Yat-sen University, Guangzhou, China
| | - Huanxi Zhang
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jun Li
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Longshan Liu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chenglin Wu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qian Fu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Min Huang
- Institule of Clinical Pharmacology, School of Pharmaceutical sciences, Sun Yat-sen University, Guangzhou, China
| | - Xiao Chen
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Changxi Wang
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Pan Chen
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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6
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Immunosuppressive Drugs. ENCYCLOPEDIA OF INFECTION AND IMMUNITY 2022. [PMCID: PMC8987166 DOI: 10.1016/b978-0-12-818731-9.00068-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Immunosuppressant is a class of medicines that inhibit or decrease the intensity of the immune response in the body. Most of these medications are used to allow the body less likely to resist a transplanted organ. In solid organ transplantation, immunosuppressive agents are needed for the activation of early-stage immunosuppression, the management of late-stage immunosuppression or for the maintenance of organ rejection. The emergence of novel agents and improvements in immunosuppression regimens after transplantation are significant factors leading to this progress. However, these drugs also increase the risk of infection, cancers and specific adverse side effects specific to each agent in patients particularly in pregnant women and fertility issues. Corona virus disease being hot topic of debate is has given positive outcome to immunosuppressive drugs however need more attention in future. Transplant centers across the world utilize multiple immunosuppression protocols; nevertheless, each patient can require an individually formulated immunosuppression regimen to manage the advantages and possible damage of treatment thus eliminating the likelihood of their primary disease recurrence.
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Bergan S, Brunet M, Hesselink DA, Johnson-Davis KL, Kunicki PK, Lemaitre F, Marquet P, Molinaro M, Noceti O, Pattanaik S, Pawinski T, Seger C, Shipkova M, Swen JJ, van Gelder T, Venkataramanan R, Wieland E, Woillard JB, Zwart TC, Barten MJ, Budde K, Dieterlen MT, Elens L, Haufroid V, Masuda S, Millan O, Mizuno T, Moes DJAR, Oellerich M, Picard N, Salzmann L, Tönshoff B, van Schaik RHN, Vethe NT, Vinks AA, Wallemacq P, Åsberg A, Langman LJ. Personalized Therapy for Mycophenolate: Consensus Report by the International Association of Therapeutic Drug Monitoring and Clinical Toxicology. Ther Drug Monit 2021; 43:150-200. [PMID: 33711005 DOI: 10.1097/ftd.0000000000000871] [Citation(s) in RCA: 87] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/29/2021] [Indexed: 12/13/2022]
Abstract
ABSTRACT When mycophenolic acid (MPA) was originally marketed for immunosuppressive therapy, fixed doses were recommended by the manufacturer. Awareness of the potential for a more personalized dosing has led to development of methods to estimate MPA area under the curve based on the measurement of drug concentrations in only a few samples. This approach is feasible in the clinical routine and has proven successful in terms of correlation with outcome. However, the search for superior correlates has continued, and numerous studies in search of biomarkers that could better predict the perfect dosage for the individual patient have been published. As it was considered timely for an updated and comprehensive presentation of consensus on the status for personalized treatment with MPA, this report was prepared following an initiative from members of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT). Topics included are the criteria for analytics, methods to estimate exposure including pharmacometrics, the potential influence of pharmacogenetics, development of biomarkers, and the practical aspects of implementation of target concentration intervention. For selected topics with sufficient evidence, such as the application of limited sampling strategies for MPA area under the curve, graded recommendations on target ranges are presented. To provide a comprehensive review, this report also includes updates on the status of potential biomarkers including those which may be promising but with a low level of evidence. In view of the fact that there are very few new immunosuppressive drugs under development for the transplant field, it is likely that MPA will continue to be prescribed on a large scale in the upcoming years. Discontinuation of therapy due to adverse effects is relatively common, increasing the risk for late rejections, which may contribute to graft loss. Therefore, the continued search for innovative methods to better personalize MPA dosage is warranted.
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Affiliation(s)
- Stein Bergan
- Department of Pharmacology, Oslo University Hospital and Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Mercè Brunet
- Pharmacology and Toxicology Laboratory, Biochemistry and Molecular Genetics Department, Biomedical Diagnostic Center, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, CIBERehd, Spain
| | - Dennis A Hesselink
- Department of Internal Medicine, Division of Nephrology and Transplantation, Erasmus MC, University Medical Center Rotterdam, The Netherlands
| | - Kamisha L Johnson-Davis
- Department of Pathology, University of Utah Health Sciences Center and ARUP Laboratories, Salt Lake City, Utah
| | - Paweł K Kunicki
- Department of Drug Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warszawa, Poland
| | - Florian Lemaitre
- Univ Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail)-UMR_S 1085, Rennes, France
| | - Pierre Marquet
- INSERM, Université de Limoges, Department of Pharmacology and Toxicology, CHU de Limoges, U1248 IPPRITT, Limoges, France
| | - Mariadelfina Molinaro
- Clinical and Experimental Pharmacokinetics Lab, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Ofelia Noceti
- National Center for Liver Tansplantation and Liver Diseases, Army Forces Hospital, Montevideo, Uruguay
| | | | - Tomasz Pawinski
- Department of Drug Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warszawa, Poland
| | | | - Maria Shipkova
- Synlab TDM Competence Center, Synlab MVZ Leinfelden-Echterdingen GmbH, Leinfelden-Echterdingen, Germany
| | - Jesse J Swen
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - Teun van Gelder
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - Raman Venkataramanan
- Department of Pharmaceutical Sciences, School of Pharmacy and Department of Pathology, Starzl Transplantation Institute, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Eberhard Wieland
- Synlab TDM Competence Center, Synlab MVZ Leinfelden-Echterdingen GmbH, Leinfelden-Echterdingen, Germany
| | - Jean-Baptiste Woillard
- INSERM, Université de Limoges, Department of Pharmacology and Toxicology, CHU de Limoges, U1248 IPPRITT, Limoges, France
| | - Tom C Zwart
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - Markus J Barten
- Department of Cardiac- and Vascular Surgery, University Heart and Vascular Center Hamburg, Hamburg, Germany
| | - Klemens Budde
- Department of Nephrology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Maja-Theresa Dieterlen
- Department of Cardiac Surgery, Heart Center, HELIOS Clinic, University Hospital Leipzig, Leipzig, Germany
| | - Laure Elens
- Integrated PharmacoMetrics, PharmacoGenomics and PharmacoKinetics (PMGK) Research Group, Louvain Drug Research Institute (LDRI), Université Catholique de Louvain (UCLouvain), Brussels, Belgium
| | - Vincent Haufroid
- Louvain Centre for Toxicology and Applied Pharmacology (LTAP), Institut de Recherche Expérimentale et Clinique, UCLouvain and Department of Clinical Chemistry, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Satohiro Masuda
- Department of Pharmacy, International University of Health and Welfare Narita Hospital, Chiba, Japan
| | - Olga Millan
- Pharmacology and Toxicology Laboratory, Biochemistry and Molecular Genetics Department, Biomedical Diagnostic Center, Hospital Clinic of Barcelona, University of Barcelona, IDIBAPS, CIBERehd, Spain
| | - Tomoyuki Mizuno
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Dirk J A R Moes
- Department of Clinical Pharmacy & Toxicology, Leiden University Medical Center, Leiden, The Netherlands
| | - Michael Oellerich
- Department of Clinical Pharmacology, University Medical Center Göttingen, Georg-August-University Göttingen, Göttingen, Germany
| | - Nicolas Picard
- INSERM, Université de Limoges, Department of Pharmacology and Toxicology, CHU de Limoges, U1248 IPPRITT, Limoges, France
| | | | - Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital, Heidelberg, Germany
| | - Ron H N van Schaik
- Department of Clinical Chemistry, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Nils Tore Vethe
- Department of Pharmacology, Oslo University Hospital and Department of Pharmacy, University of Oslo, Oslo, Norway
| | - Alexander A Vinks
- Department of Pharmacy, International University of Health and Welfare Narita Hospital, Chiba, Japan
| | - Pierre Wallemacq
- Clinical Chemistry Department, Cliniques Universitaires St Luc, Université Catholique de Louvain, LTAP, Brussels, Belgium
| | - Anders Åsberg
- Department of Transplantation Medicine, Oslo University Hospital-Rikshospitalet and Department of Pharmacy, University of Oslo, Oslo, Norway; and
| | - Loralie J Langman
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
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8
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Rong Y, Jun H, Kiang TKL. Population pharmacokinetics of mycophenolic acid in paediatric patients. Br J Clin Pharmacol 2021; 87:1730-1757. [PMID: 33118201 DOI: 10.1111/bcp.14590] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/07/2020] [Accepted: 09/22/2020] [Indexed: 12/14/2022] Open
Abstract
Mycophenolic acid (MPA) is widely used in paediatric kidney transplant patients and sometimes prescribed for additional indications. Population pharmacokinetic or pharmacodynamic modelling has been frequently used to characterize the fixed, random and covariate effects of MPA in adult patients. However, MPA population pharmacokinetic data in the paediatric population have not been systematically summarized. The objective of this narrative review was to provide an up-to-date critique of currently available paediatric MPA population pharmacokinetic models, with emphases on modelling techniques, pharmacological findings and clinical relevance. PubMed and EMBASE were searched from inception of database to May 2020, where a total of 11 studies have been identified representing kidney transplant (n = 4), liver transplant (n = 1), haematopoietic stem cell transplant (n = 1), idiopathic nephrotic syndrome (n = 2), systemic lupus erythematosus (n = 2), and a combined population consisted of kidney, liver and haematopoietic stem cell transplant patients (n = 1). Critical analyses were provided in the context of MPA absorption, distribution, metabolism, excretion and bioavailability in this paediatric database. Comparisons to adult patients were also provided. With respect to clinical utility, Bayesian estimation models (n = 6) with acceptable accuracy and precision for MPA exposure determination have also been identified and systematically evaluated. Overall, our analyses have identified unique features of MPA clinical pharmacology in the paediatric population, while recognizing several gaps that still warrant further investigations. This review can be used by pharmacologists and clinicians for improving MPA pharmacokinetic-pharmacodynamic modelling and patient care.
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Affiliation(s)
- Yan Rong
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
| | - Heajin Jun
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada.,College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Tony K L Kiang
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, Canada
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9
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Fungal Biopharmaceuticals: Current Research, Production, and Potential Applications. Fungal Biol 2021. [DOI: 10.1007/978-3-030-85603-8_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Ehren R, Schijvens AM, Hackl A, Schreuder MF, Weber LT. Therapeutic drug monitoring of mycophenolate mofetil in pediatric patients: novel techniques and current opinion. Expert Opin Drug Metab Toxicol 2020; 17:201-213. [PMID: 33107768 DOI: 10.1080/17425255.2021.1843633] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Introduction: Mycophenolate mofetil (MMF) is an ester prodrug of the immunosuppressant mycophenolic acid (MPA) and is recommended and widely used for maintenance immunosuppressive therapy in solid organ and stem-cell transplantation as well as in immunological kidney diseases. MPA is a potent, reversible, noncompetitive inhibitor of the inosine monophosphate dehydrogenase (IMPDH), a crucial enzyme in the de novo purine synthesis in T- and B-lymphocytes, thereby inhibiting cell-mediated immunity and antibody formation. The use of therapeutic drug monitoring (TDM) of MMF is still controversial as outcome data of clinical trials are equivocal. Areas covered: This review covers in great depth the existing literature on TDM of MMF in the field of pediatric (kidney) transplantation. In addition, the relevance of TDM in immunological kidney diseases, in particular childhood nephrotic syndrome is highlighted. Expert opinion: TDM of MMF has the potential to optimize therapy in pediatric transplantation as well as in nephrotic syndrome. Limited sampling strategies to estimate MPA exposure increase its feasibility. Future perspectives rather encompass approaches reflecting total immunosuppressive load than single drug TDM.
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Affiliation(s)
- Rasmus Ehren
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne , Cologne, Germany
| | - Anne M Schijvens
- Department of Pediatric Nephrology, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen, The Netherlands
| | - Agnes Hackl
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne , Cologne, Germany
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Amalia Children's Hospital, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center , Nijmegen, The Netherlands
| | - Lutz T Weber
- Faculty of Medicine and University Hospital Cologne, Department of Pediatrics, University of Cologne , Cologne, Germany
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11
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Liu Y, Liu L, Li J, Fu Q, Zhang H, Wu C, Li J, Zhong G, Zheng Y, Chen X, Wang C, Chen P. Validated LC-MS/MS method for quantitation of total and free mycophenolic acid concentration and its application to a pharmacokinetic study in pediatric renal transplant recipients. Biomed Chromatogr 2020; 35:e4989. [PMID: 32959916 DOI: 10.1002/bmc.4989] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/01/2020] [Accepted: 09/12/2020] [Indexed: 12/30/2022]
Abstract
A simple and sensitive LC-MS/MS method was established to quantify total and free mycophenolic acid (MPA) plasma concentrations during immunosuppressive medication for pediatric renal transplantation. The chromatographic separation was performed with the Hypersil GOLD C18 column, using a mobile phase consisting of 0.1% formic acid in water and acetonitrile (60:40, v/v) at an isocratic flow rate of 0.4 ml/min. An Agilent 6420 triple quadrupole mass spectrometer was operated via a positive electrospray ionization interface using the transitions m/z 321.14 → 206.9 for MPA and m/z 324.15 → 209.9 for MPA-d3 (internal standard). The linearity was 0.1-50 μg/ml for total MPA and 0.0025-0.5 μg/ml for free MPA. The within-run and between-run precisions were all <5% and accuracy was within 96.23-107.63%. The validated method was successfully aspplied to a pharmacokinetic study in 28 pediatric renal recipients. The mean free fraction of MPA in our patients was 0.89% (ranging from 0.62 to 1.25%) and albumin level played a major role in the variability of free fraction of MPA, thus, in pediatric patients with hypoproteinemia, close free drug monitoring and dose adjustments should be considered to prevent toxicity.
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Affiliation(s)
- Yan Liu
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Department of Pharmacy, the Third Affiliated Hospital of Nanchang University, Nanchang, China
| | - Longshan Liu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jingjie Li
- Reproductive medicine center, the Sixth Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Qian Fu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huanxi Zhang
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chenglin Wu
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jun Li
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Guoping Zhong
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Yifan Zheng
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiao Chen
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Changxi Wang
- Organ Transplant Center, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory on Organ Donation and Transplant Immunology, Guangzhou, China
| | - Pan Chen
- Department of Pharmacy, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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12
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Generation and Validation of a Limited Sampling Strategy to Monitor Mycophenolic Acid Exposure in Children With Nephrotic Syndrome. Ther Drug Monit 2020; 41:696-702. [PMID: 31425441 DOI: 10.1097/ftd.0000000000000671] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Mycophenolate mofetil (MMF) plays an increasingly important role in the treatment of children with nephrotic syndrome, especially in steroid sparing protocols. Recent publications show the relationship of exposure to its active moiety mycophenolic acid (MPA) and clinical efficacy. Performance of full-time pharmacokinetic (PK) profiles, however, is inconvenient and laborious. Established limited sampling strategies (LSS) to estimate the area under the concentration (AUC) versus time curve of MPA (MPA-AUC) in pediatric renal transplant recipients cannot be easily transferred to children suffering from nephrotic syndrome, mainly because of the lack of concomitant immunosuppressive therapy. We therefore aimed for the generation and validation of a LSS to estimate MPA exposure to facilitate therapeutic drug monitoring in children with nephrotic syndrome. METHODS We performed 27 complete PK profiles in 23 children in remission [mean age (±SD):12.3 ± 4.26 years] to generate and validate an LSS. Sampling time points were before administration (C0) and 0.5, 1, 1.5, 2, 4, 6, 8, and 12 hours after the administration of MMF. MPA was measured by enzyme multiplied immunoassay technique. There was no concomitant treatment with calcineurin inhibitors. RESULTS Mean daily dose of MMF was 927 ± 209 mg/m of body surface area resulting in a mean MPA-AUC0-12 value of 59.2 ± 29.3 mg × h/L and a predose level of 3.03 ± 2.24 mg/L. Between-patient variability of dose-normalized MPA-AUC0-12 was high (coefficient of variation: 45.5%). Correlation of predose levels with the corresponding MPA-AUC0-12 was moderate (r = 0.59) in a subgroup of 18 patients (20 PK profiles, generation group). An algorithm based on 3 PK sampling time points during the first 2 hours after MMF dosing (estimated AUC0-12 = 8.7 + 4.63 × C0 + 1.90 × C1 + 1.52 × C2) was able to predict MPA-AUC with a low percentage prediction error (3.88%) and a good correlation of determination (r = 0.90). Validation of this algorithm in a randomized separate group of 6 patients (7 PK profiles, validation group) resulted in comparably good correlation (r = 0.95) and low percentage prediction error (5.57%). CONCLUSIONS An abbreviated profile within the first 2 hours after MMF dosing gives a good estimate of MPA exposure in children with nephrotic syndrome and hence has the potential to optimize MMF therapy.
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13
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The Application of Inosine 5'-Monophosphate Dehydrogenase Activity Determination in Peripheral Blood Mononuclear Cells for Monitoring Mycophenolate Mofetil Therapy in Children with Nephrotic Syndrome. Pharmaceuticals (Basel) 2020; 13:ph13080200. [PMID: 32824803 PMCID: PMC7463457 DOI: 10.3390/ph13080200] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/14/2020] [Accepted: 08/16/2020] [Indexed: 11/16/2022] Open
Abstract
In pediatric nephrotic syndrome, recommended mycophenolic acid (MPA) pharmacokinetics are higher than those for transplant recipients. In MPA therapeutic monitoring, inosine-5'-monophosphate dehydrogenase (IMPDH) activity may be useful. We modified the method established for renal transplant recipients and determined IMPDH activity in peripheral blood mononuclear cells (PBMCs) from healthy volunteers and children (4-16 years) with nephrotic syndrome treated with mycophenolate mofetil (MMF). From children, four blood samples were collected, and MPA concentrations were also determined. IMPDH activity was calculated using xanthosine monophosphate (XMP) normalized with adenosine monophosphate (AMP), both determined with the HPLC-UV method. The modified method was accurate, precise, and linear for AMP and XMP within 0.50-50.0 μmoL/L. Mean IMPDH activity in volunteers was 45.97 ± 6.24 µmoL·s-1·moL-1 AMP, whereas for children, the values were variable and amounted to 39.23 ± 27.40 µmoL·s-1·moL-1 AMP and 17.97 ± 15.24 µmoL·s-1·moL-1 AMP before the next MMF dose and 1 h afterward, respectively. The modified method may be applied to IMPDH activity determination in children with nephrotic syndrome treated with MMF. IMPDH activity should be determined after one thawing of PBMCs due to the change in AMP and XMP concentrations after subsequent thawing. For children, the lowest IMPDH activity was observed concomitantly with the highest MPA concentration.
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14
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Ferreira PCL, Thiesen FV, Pereira AG, Zimmer AR, Fröehlich PE. A short overview on mycophenolic acid pharmacology and pharmacokinetics. Clin Transplant 2020; 34:e13997. [DOI: 10.1111/ctr.13997] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 05/15/2020] [Accepted: 05/21/2020] [Indexed: 02/05/2023]
Affiliation(s)
| | - Flavia Valladao Thiesen
- Escola de Ciências da Saúde e da Vida Pontifícia Universidade Católica do Rio Grande do Sul Porto Alegre Brazil
| | - Andrea Garcia Pereira
- Graduate Program in Pharmaceutical Sciences Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Aline Rigon Zimmer
- Graduate Program in Pharmaceutical Sciences Federal University of Rio Grande do Sul Porto Alegre Brazil
| | - Pedro Eduardo Fröehlich
- Graduate Program in Pharmaceutical Sciences Federal University of Rio Grande do Sul Porto Alegre Brazil
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15
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Tönshoff B. Immunosuppressive therapy post-transplantation in children: what the clinician needs to know. Expert Rev Clin Immunol 2020; 16:139-154. [DOI: 10.1080/1744666x.2020.1714437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Burkhard Tönshoff
- Department of Pediatrics I, University Children’s Hospital, Heidelberg, Germany
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16
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Metz DK, Holford N, Kausman JY, Walker A, Cranswick N, Staatz CE, Barraclough KA, Ierino F. Optimizing Mycophenolic Acid Exposure in Kidney Transplant Recipients: Time for Target Concentration Intervention. Transplantation 2019; 103:2012-2030. [PMID: 31584924 PMCID: PMC6756255 DOI: 10.1097/tp.0000000000002762] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/29/2019] [Accepted: 04/03/2019] [Indexed: 12/24/2022]
Abstract
The immunosuppressive agent mycophenolate is used extensively in kidney transplantation, yet dosing strategy applied varies markedly from fixed dosing ("one-dose-fits-all"), to mycophenolic acid (MPA) trough concentration monitoring, to dose optimization to an MPA exposure target (as area under the concentration-time curve [MPA AUC0-12]). This relates in part to inconsistent results in prospective trials of concentration-controlled dosing (CCD). In this review, the totality of evidence supporting mycophenolate CCD is examined: pharmacological characteristics, observational data linking exposure to efficacy and toxicities, and randomized controlled trials of CCD, with attention to dose optimization method and exposure achieved. Fixed dosing of mycophenolate consistently leads to underexposure associated with rejection, as well as overexposure associated with toxicities. When CCD is driven by pharmacokinetic calculation to a target concentration (target concentration intervention), MPA exposure is successfully controlled and clinical benefits are seen. There remains a need for consensus on practical aspects of mycophenolate target concentration intervention in contemporary tacrolimus-containing regimens and future research to define maintenance phase exposure targets. However, given ongoing consequences of both overimmunosuppression and underimmunosuppression in kidney transplantation, impacting short- and long-term outcomes, these should be a priority. The imprecise "one-dose-fits-all" approach should be replaced by the clinically proven MPA target concentration strategy.
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Affiliation(s)
- David K. Metz
- Department of Nephrology, Royal Children’s Hospital, Melbourne, VIC, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
- Clinical Pharmacology Unit, Royal Children’s Hospital, Melbourne, VIC, Australia
| | - Nick Holford
- Department of Pharmacology and Clinical Pharmacology, University of Auckland, Auckland, New Zealand
| | - Joshua Y. Kausman
- Department of Nephrology, Royal Children’s Hospital, Melbourne, VIC, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Amanda Walker
- Department of Nephrology, Royal Children’s Hospital, Melbourne, VIC, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
| | - Noel Cranswick
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Murdoch Children’s Research Institute, Melbourne, VIC, Australia
- Clinical Pharmacology Unit, Royal Children’s Hospital, Melbourne, VIC, Australia
| | | | - Katherine A. Barraclough
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Department of Nephrology, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Francesco Ierino
- Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia
- Department of Nephrology, St Vincent’s Health, Melbourne, VIC, Australia
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17
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Strommen AM, Moss MC, Goebel J, Bock M. Donor-specific antibodies in a pediatric kidney transplant population-Prevalence and association with antiproliferative drug dosing. Pediatr Transplant 2019; 23:e13511. [PMID: 31168879 DOI: 10.1111/petr.13511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 03/13/2019] [Accepted: 05/05/2019] [Indexed: 12/01/2022]
Abstract
Prevalence and implications of anti-HLA class I and class II antibodies are beginning to be better characterized in pediatric kidney transplant recipients. dnDSA formation is predictive of AMR and downstream diminished graft function and survival. However, risk factors for the development of dnDSA are not well defined in this patient population. After introducing DSA surveillance into our pediatric kidney transplant program, we are reporting the prevalence of class I and class II DSA in 67 otherwise stable recipients. Secondary end-points included risk factors for DSA development and assessment of graft function. Significantly, lower median daily MMF doses were observed in patients with DSAs compared to patients without DSAs (371 vs 617 mg/m2 /d, respectively; P = 0.035). Class II DSA formation was more common, with a prevalence of 17.9%, as compared to 10.4% for class I DSA. Estimated glomerular filtration rate was also decreased in patients with positive DSA vs those with negative titers (71, SD 25 vs 78, SD 29 mL/min/1.73 m2 , respectively; P = 0.034). We conclude that reduced-dose MMF is associated with dnDSA and DSA is associated with diminished graft function in stable pediatric kidney transplant recipients.
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Affiliation(s)
- Amanda M Strommen
- Department of Pharmacy, Children's Hospital Colorado, Aurora, Colorado
| | - Mary C Moss
- Department of Pharmacy, Children's Hospital Colorado, Aurora, Colorado
| | - Jens Goebel
- Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, Colorado
| | - Margret Bock
- Section of Pediatric Nephrology, Children's Hospital Colorado, Aurora, Colorado
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18
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Nosadini M, Gadian J, Lim M, Sartori S, Thomas T, Dale RC. Mycophenolate mofetil in paediatric autoimmune or immune-mediated diseases of the central nervous system: clinical experience and recommendations. Dev Med Child Neurol 2019; 61:458-468. [PMID: 30221751 DOI: 10.1111/dmcn.14020] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/17/2018] [Indexed: 12/14/2022]
Abstract
AIM To gather data on mycophenolate mofetil (MMF) in paediatric autoimmune/immune-mediated central nervous system (CNS) conditions, focusing on safety and factors that may affect MMF efficacy. METHOD Retrospective, multicentre study based on four paediatric neurology centres. RESULTS Forty-four children were included (30 females, 14 males): 19 had proven/suspected autoimmune encephalitis, 14 had inflammatory demyelinating CNS diseases, and 11 had other autoimmune/immune-mediated CNS conditions. Before MMF, all received first-line immune therapies, and 17 had second-line rituximab and/or cyclophosphamide. MMF was started at a median of 9.5 months from disease onset (range 1-127mo) (median age 9y 4mo, range 1y 5mo-16y 5mo), and was used for median 18 months (range 0.3-73mo). On MMF, 31 patients were relapse-free, whereas eight relapsed (excluding patients with chronic-progressive course). Relapses on MMF were associated with medication weaning/cessation, or with suboptimal MMF dosage/duration. Adverse events of MMF occurred in eight patients: six moderate (gastrointestinal, movement disorder, dermatological) and two severe (infectious). INTERPRETATION MMF use in paediatric neuroimmunology is heterogeneous, although relatively safe. We have identified factors that may affect MMF efficacy and provide recommendations on MMF usage. WHAT THIS PAPER ADDS Mycophenolate mofetil (MMF) use was heterogeneous with relatively common adverse events, although mostly not severe. MMF treatment reduced median annualized relapse rate, although 20% of patients relapsed on MMF. A high relapse rate pre-MMF and late MMF start were associated with higher probability of relapsing on MMF. Most relapses were associated with suboptimal MMF dosage, short MMF duration, or concurrent medication weaning/discontinuation.
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Affiliation(s)
- Margherita Nosadini
- Neuroimmunology Group, Institute for Neuroscience and Muscle Research, Kids Research at the Children's Hospital at Westmead, University of Sydney, Westmead, Australia.,Paediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University Hospital of Padua, Padua, Italy
| | - Jonathan Gadian
- Children's Neurosciences Centre, Guy's & St Thomas' NHS Foundation Trust, Kings Health Partners Academic Health Science Centre, Evelina London Children's Hospital, London, UK.,Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Ming Lim
- Children's Neurosciences Centre, Guy's & St Thomas' NHS Foundation Trust, Kings Health Partners Academic Health Science Centre, Evelina London Children's Hospital, London, UK
| | - Stefano Sartori
- Paediatric Neurology and Neurophysiology Unit, Department of Women's and Children's Health, University Hospital of Padua, Padua, Italy
| | | | - Russell C Dale
- Neuroimmunology Group, Institute for Neuroscience and Muscle Research, Kids Research at the Children's Hospital at Westmead, University of Sydney, Westmead, Australia
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19
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Comparison of plasma and oral fluid concentrations of mycophenolic acid and its glucuronide metabolite by LC-MS in kidney transplant patients. Eur J Clin Pharmacol 2019; 75:553-559. [DOI: 10.1007/s00228-018-02614-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/18/2018] [Indexed: 10/27/2022]
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20
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Abstract
The goal of immunosuppressive therapy post-transplantation in pediatric renal transplant recipients is to prevent acute and chronic rejection while minimizing drug side effects. Most therapies alter immune response mechanisms but are not immunologically specific, and a careful balance is required to find the dose that prevents rejection of the graft while minimizing the risks of overimmunosuppression leading to infection and cancer. While this chapter because of space constraints focuses on immunosuppressive therapy in pediatric renal transplant recipients, many aspects can be applied on pediatric recipients of other solid organ transplants such as the liver and heart. The major maintenance immunosuppressive agents currently used in various combination regimens are tacrolimus, cyclosporine, mycophenolate mofetil, azathioprine, everolimus, sirolimus, and glucocorticoids (steroids). Although data from adult renal transplantation trials are used to help guide management decisions in pediatric patients, immunosuppressive therapy in pediatric renal transplant recipients often must be modified because of the unique dosage requirements and clinical effects of these agents in children, including their impact on growth and development. The optimal immunosuppressive therapy post-transplant is not established. The goal remains to find the best combination of immunosuppressive agents that optimizes allograft survival by preventing acute rejection while limiting drug toxicities.
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21
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Clinical aspects of tacrolimus use in paediatric renal transplant recipients. Pediatr Nephrol 2019; 34:31-43. [PMID: 29479631 DOI: 10.1007/s00467-018-3892-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/08/2018] [Accepted: 01/10/2018] [Indexed: 12/30/2022]
Abstract
The calcineurin inhibitor tacrolimus, cornerstone of most immunosuppressive regimens, is a drug with a narrow therapeutic window: underexposure can lead to allograft rejection and overexposure can result in an increased incidence of infections, toxicity and malignancies. Tacrolimus is metabolised in the liver and intestine by the cytochrome P450 3A (CYP3A) isoforms CYP3A4 and CYP3A5. This review focusses on the clinical aspects of tacrolimus pharmacodynamics, such as efficacy and toxicity. Factors affecting tacrolimus pharmacokinetics, including pharmacogenetics and the rationale for routine CYP3A5*1/*3 genotyping in prospective paediatric renal transplant recipients, are also reviewed. Therapeutic drug monitoring, including pre-dose concentrations and pharmacokinetic profiles with the available "reference values", are discussed. Factors contributing to high intra-patient variability in tacrolimus exposure and its impact on clinical outcome are also reviewed. Lastly, suggestions for future research and clinical perspectives are discussed.
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22
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Medeiros M, Lumini J, Stern N, Castañeda-Hernández G, Filler G. Generic immunosuppressants. Pediatr Nephrol 2018; 33:1123-1131. [PMID: 28733752 DOI: 10.1007/s00467-017-3735-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 06/20/2017] [Indexed: 11/24/2022]
Abstract
Immunosuppressive drugs for solid organ transplantation are critical dose drugs with a narrow therapeutic index. Many of the most commonly used innovator drugs are off patent and have been replicated by generic counterparts, often at substantial cost-savings to the patient. However, serious adverse events caused by the transition from innovator to generic medications, specifically in pediatric solid organ transplant recipients, have questioned these autosubstitutions. The purpose of this review is to summarize the criteria set forth by the regulatory bodies, and to examine how major immunosuppressive drugs conform to these recommendations. Regulatory bodies have established inconsistent criteria to demonstrate bioequivalence between innovator and generic medications, causing approved generic variations to have varying levels of equivalence with the innovator drugs. In order to minimize the risk for under-immunosuppression, the following recommendations have been concluded. Brand prescribing of cyclosporine and tacrolimus are recommended due to evidence of adverse events after conversion to generic formulations and differences in dissolution parameters. Mycophenolate mofetil (MMF) shows better bioequivalence between innovator and generic formulations, however caution should be advised when switching between formulations. The institution of 'innovator only' policies may be appropriate at this time in order to minimize the risk of under-immunosuppressing patients until the evidence of more stringent bioequivalence has been established.
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Affiliation(s)
- Mara Medeiros
- Unidad de Investigacion en Nefrologia, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico.,Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Julia Lumini
- Department of Biomedical Life Sciences, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Noah Stern
- Department of Paediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada
| | | | - Guido Filler
- Department of Paediatrics, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada. .,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N6A 5W9, Canada. .,Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, N5A 5A5, Canada. .,Paediatric Nephrology, University of Western Ontario, Children's Hospital, London Health Science Centre, 800 Commissioners Road East, London, ON, N6A 5W9, Canada.
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23
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Friedersdorff F, Koch TM, Banuelos-Marco B, Gonzalez R, Fuller T, von Mechow S, Müller D, Lingnau A. Long-Term Follow-Up after Paediatric Kidney Transplantation and Influence Factors on Graft Survival: A Single-Centre Experience of 16 years. Urol Int 2018. [DOI: 10.1159/000487195] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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24
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Charnaya O, Tuchman S, Moudgil A. Results of early treatment for de novo donor-specific antibodies in pediatric kidney transplant recipients in a cross-sectional and longitudinal cohort. Pediatr Transplant 2018; 22. [PMID: 29356221 DOI: 10.1111/petr.13108] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/06/2017] [Indexed: 11/27/2022]
Abstract
The development of dnDSA anti-HLA antibodies has been shown to be a significant risk factor for graft failure. In 2008, we instituted a routine protocol of standardized monitoring and treatment of dnDSA in pediatric kidney transplant recipients. Of 67 first-time pediatric kidney transplant recipients, 26 (38%) developed dnDSA after 1.36 (IQ 1-2.14) years. Coefficient of variance of tacrolimus, a surrogate marker of non-adherence, was found to be the single most important risk factor for dnDSA development. Overall, there was a significant reduction in dnDSA with treatment in 19 (76%) children. No difference in graft survival and estimated glomerular filtration rate was noted between dnDSA negative and those treated for dnDSA. There was an increased risk of hospitalization in those treated for dnDSA. This study suggests that early detection and treatment of dnDSA can help to prevent graft failure and preserve graft function in the short term. Future studies and longer follow-up are needed to fully elucidate the effect of early detection and treatment of dnDSA in pediatric kidney transplant recipients.
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Affiliation(s)
- Olga Charnaya
- Division of Pediatric Nephrology, Children's National Health System, Washington, DC, USA
| | - Shamir Tuchman
- Division of Pediatric Nephrology, Children's National Health System, Washington, DC, USA
| | - Asha Moudgil
- Division of Pediatric Nephrology, Children's National Health System, Washington, DC, USA
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25
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A Retrospective Study on Mycophenolic Acid Drug Interactions: Effect of Prednisone, Sirolimus, and Tacrolimus With MPA. Ther Drug Monit 2017; 39:220-228. [DOI: 10.1097/ftd.0000000000000403] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Filler G, Alvarez-Elías AC, McIntyre C, Medeiros M. The compelling case for therapeutic drug monitoring of mycophenolate mofetil therapy. Pediatr Nephrol 2017; 32:21-29. [PMID: 26921212 DOI: 10.1007/s00467-016-3352-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Revised: 01/25/2016] [Accepted: 01/29/2016] [Indexed: 11/26/2022]
Abstract
We have reviewed current evidence on the therapeutic drug monitoring (TDM) of mycophenolic acid (MPA) in relationship to drug efficacy and safety. The relationship between actual MPA exposure and mycophenolate mofetil (MMF) dose has been shown to be weak in children and adolescents. The TDM of MPA exposure should ideally be performed using full pharmacokinetic profiles or limited sampling strategies. Recent evidence has provided some rationale for using the post-dose trough level as a single measure. In terms of short-term efficacy, there is strong evidence that a MPA area under the time-concentration curve of >30 mg × h/L reduces acute rejection episodes early after renal transplantation, and there is evolving evidence that aiming for the same exposure over the long term may be a viable strategy to reduce the formation of donor-specific antibodies. Strong evidence also supports the existence of important drug interactions and age/developmental dependent differences in drug metabolism that may necessitate the need for TDM of MMF therapy. Based on these findings and given the substantial inter- and intra-patient variability of MPA exposure, it would appear that MMF therapy should be subject to TDM to avoid over- and under-dosing. This may be a viable strategy to reduce treatment-emergent adverse events and to increase the effective pediatric transplant survival rates.
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Affiliation(s)
- Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5 W9, Canada.
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, N5A 5A5, Canada.
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5 W9, Canada.
- Department of Pediatrics, Children's Hospital, London Health Science Centre, Western University, 800 Commissioners Road East, London, ON, N6A 5 W9, Canada.
| | - Ana Catalina Alvarez-Elías
- Department of Pediatrics, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5 W9, Canada
- Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
- Laboratorio de Investigacion en Nefrologia, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico
| | - Christopher McIntyre
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, N6A 5 W9, Canada
| | - Mara Medeiros
- Laboratorio de Investigacion en Nefrologia, Hospital Infantil de Mexico Federico Gomez, Mexico City, Mexico
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, Mexico
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Pharmacokinetics of Mycophenolic Acid and Dose Optimization in Children After Intestinal Transplantation. Ther Drug Monit 2016; 39:37-42. [PMID: 27898598 DOI: 10.1097/ftd.0000000000000363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Mycophenolate mofetil (MMF) or enteric-coated mycophenolate sodium (MPS) is now commonly used in pediatric intestinal transplantation (Tx), but to date, no clear recommendations regarding the dosing regimen have been made in this population. The aim of this study was to determine the MMF/MPS dosage required to achieve an area under the plasma concentration-time curve from 0 to 12 hours (AUC0-12) for mycophenolic acid (MPA) greater than 30 mg·h·L in children after intestinal transplantation. METHODS A pharmacokinetic study was conducted in 8 children (median, 9.4 years; range, 0.75-15.8 years) at a median time of 113 months (range, 1.5-160 months) after intestinal transplantation. RESULTS MMF was initially introduced at a low median starting dose of 687 mg·m·d (range, 310-1414 mg·m·d). One of the 3 patients who received MPS and 2 of the 6 patients who received MMF had an MPA AUC0-12 value below 30 mg.h.L. The median MMF dosage had to be increased by 91% (1319 mg·m·d versus 687 mg·m·d) to reach AUC0-12 values above the defined target level of 30 mg·h·L. CONCLUSIONS When used in combination with tacrolimus and steroids, an initial MMF dose of 600 mg/m twice a day would be recommended to children after intestinal transplantation to achieve MPA exposure similar to those observed in adults and children after the transplantation of other organs. Further studies are required to recommend a suitable dosage for pediatric intestinal transplant recipients who receive MPA.
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Yoo EC, Alvarez-Elías AC, Todorova EK, Filler G. Developmental changes of MPA exposure in children. Pediatr Nephrol 2016; 31:975-82. [PMID: 26743220 DOI: 10.1007/s00467-015-3303-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/02/2015] [Accepted: 12/11/2015] [Indexed: 11/28/2022]
Abstract
BACKGROUND Developmental changes (ontogeny) of drug disposition of Mycophenolate mofetil (MMF) have been understudied. METHODS The charts of 37 pediatric renal transplant recipients (median age 7.3 years, median follow-up 7.8 (IQR 6.6, 14.3 years) who had regular mycophenolic acid (MPA) trough level monitoring in combination with tacrolimus (n = 31) or sirolimus (n = 6) therapy were analyzed retrospectively for their dose-normalized MPA exposure, steroid dose, albumin, hematocrit, and cystatin C estimated glomerular filtration rate (eGFR). Using appropriate univariate and multivariate methods, we determined whether MPA exposure was age dependent when controlling for the confounders. RESULTS Dose-normalized MPA trough levels could be calculated in 2,128 (median 45/patient) instances. Spearman rank correlation analysis revealed that age correlated with dose-normalized MPA trough level for both body weight and body surface area, as well as serum albumin, hematocrit, steroid dose, and eGFR. In the multivariate analysis, serum albumin and steroid dose were not significant, and hematocrit only being significant when the youngest group of patients < 6 years of age was compared. eGFR was the most important confounder, but age dependency remained significant when controlling for all confounders. CONCLUSIONS Small children are at a significantly greater risk for low MPA trough levels than adolescents, highlighting the need for pharmacokinetic monitoring of MPA.
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Affiliation(s)
- Elisa C Yoo
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada, N6A 5W9
| | - Ana Catalina Alvarez-Elías
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada, N6A 5W9.,Universidad Nacional Autónoma de México, Mexico City, Mexico, 04510
| | | | - Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada, N6A 5W9. .,Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, Ontario, Canada, N5A 5A5. .,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada, 5A 5A5. .,Department of Pediatrics, Children's Hospital, London Health Sciences Centre, University of Western Ontario, 800 Commissioners Road East, London, ON, Canada, N6A 5W9.
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29
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Martial LC, Jacobs BAW, Cornelissen EAM, de Haan AFJ, Koch BCP, Burger DM, Aarnoutse RE, Schreuder MF, Brüggemann RJM. Pharmacokinetics and target attainment of mycophenolate in pediatric renal transplant patients. Pediatr Transplant 2016; 20:492-9. [PMID: 26923724 DOI: 10.1111/petr.12695] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/29/2016] [Indexed: 01/23/2023]
Abstract
MPA is an immunosuppressive agent used to prevent graft rejection after renal transplantation. MPA shows considerable inter- and intraindividual variability in exposure in children and has a defined therapeutic window, and TDM is applied to individualize therapy. We aimed to study the exposure to MPA measured as the AUC in pediatric renal transplant patients, to identify factors influencing exposure and to assess target attainment. Children transplanted between 1998 and 2014 in a single center were included. Two groups were identified: Group 1 (AUC <3 wk post-transplantation) and Group 2 (AUC >18 months post-transplantation). Therapeutic targets were set at: AUC0-12h of 30-60 mg h/L. A total of 39 children were included in Group 1 (median age 13.3 yr) vs. 14 in Group 2 (median age 13.4 yr). AUC0-12h was 29.7 mg h/L in Group 1 and 56.6 mg h/L in Group 2, despite a lower dosage in Group 2 (584 and 426 mg/m(2) , respectively). About 46% of patients reached the target AUC0-12h in Group 1. Time since transplantation and serum creatinine were significantly associated with MPA exposure (p < 0.001), explaining 36% of the variability. Individualization of the mycophenolate dose by more intense and more early TDM could improve target attainment.
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Affiliation(s)
- Lisa C Martial
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University, Nijmegen, The Netherlands
| | - Bart A W Jacobs
- Department of Clinical Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | | | - Anton F J de Haan
- Radboud Institute for Health Sciences, Radboud University, Nijmegen, The Netherlands
| | - Birgit C P Koch
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - David M Burger
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University, Nijmegen, The Netherlands
| | - Rob E Aarnoutse
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University, Nijmegen, The Netherlands
| | - Michiel F Schreuder
- Department of Pediatric Nephrology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Roger J M Brüggemann
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, The Netherlands.,Radboud Institute for Health Sciences, Radboud University, Nijmegen, The Netherlands
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Filler G, Todorova EK, Bax K, Alvarez-Elías AC, Huang SHS, Kobrzynski MC. Minimum mycophenolic acid levels are associated with donor-specific antibody formation. Pediatr Transplant 2016; 20:34-8. [PMID: 26589470 DOI: 10.1111/petr.12637] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/16/2015] [Indexed: 12/13/2022]
Abstract
Although de novo DSA are associated with inferior graft survival, there are no effective strategies to prevent their formation. Underexposure to MPA (prodrug: MMF) also contributes to rejection rates early after transplantation, but the effect of this phenomenon on the formation of DSA long-term post-transplantation is unknown. Data are expressed as mean (standard deviation). All available data from 32 renal transplant recipients (age at transplantation 7.5 [4.5] yr) on tacrolimus and MPA immunosuppression with an average follow-up of 9.4 (s.d. 4.6) yr were analyzed. DSA were measured using the Luminex assay (>500 MFI was considered DSA-positive). Tacrolimus and MPA levels were measured with the Abbot Tacro II and EMIT assay, respectively. Among 1964 MPA and 3462 tacrolimus trough levels, the average MPA trough level was 3.2 (1.5) mg/L and the average tacrolimus level was 6.7 (2.8) ng/mL. At last follow-up, only 5/32 patients had undetectable DSA, with 5/32 having no class I antibodies and 6/32 having no class II antibodies. DSA formation was associated with a lower minimum MPA trough level (0.27 [0.23] vs. 0.47 [0.18] mg) and cystatin C eGFR (48 [21] vs. 70 [23] mL/min/1.73 m(2)) for class I DSA formers. The average eGFR of patients without class I DSA was 70 (23) mL/min/1.73 m(2), whereas the average eGFR of patients with class I DSA was 48 (21) mL/min/1.73 m(2) (p = 0.0071). MPA trough levels <1.3 mg/L long-term post-transplantation are associated with the formation of DSA. The association between the formation of DSA and minimum MPA exposure may support a strategy for preventing the formation of DSA.
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Affiliation(s)
- Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | | | - Kevin Bax
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada
| | | | - Shih-Han Susan Huang
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada.,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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31
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Tönshoff B. Should we monitor mycophenolic acid plasma levels in pediatric renal transplantation? Pediatr Transplant 2015; 19:665-6. [PMID: 26435035 DOI: 10.1111/petr.12605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Burkhard Tönshoff
- Department of Pediatrics I, University Children's Hospital, Heidelberg, Germany.
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32
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Todorova EK, Huang SHS, Kobrzynski MC, Filler G. What is the intrapatient variability of mycophenolic acid trough levels? Pediatr Transplant 2015. [PMID: 26201386 DOI: 10.1111/petr.12559] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
TDM of MPA, the active compound of MMF, is rarely used despite its substantial intra- and interpatient variability. Little is known about the utility of long-term MPA TDM. Data are expressed as mean (one standard deviation). All available data from 27 renal transplant recipients (mean age at transplantation: 7.7 [5.0] yr) with an average follow-up of 9.3 (4.6) yr were analyzed. MPA levels were measured using the EMIT. GFR was measured using cystatin C and eGFR was calculated using the Filler formula. Intrapatient CV of the trough level was calculated as the ratio of the mean divided by one standard deviation. Mean cystatin C eGFR was 56.9 (24.4) mL/min/1.73 m(2) . There was a weak but significant correlation between the MPA trough level and the AUC (Spearman r = 0.6592, p < 0.0001). A total of 1964 MPA trough levels (73 [45]/patient) were measured, as compared to 3462 Tac trough levels (144 [71]/patient). The average MPA trough level was 3.01 (1.26) mg/L and the average trough Tac level was 7.3 (1.8) ng/mL. Intrapatient CV was statistically higher (p = 0.00093) for MPA at 0.68 (0.29) when compared to Tac with a CV of 0.46 (0.12). CV did not correlate with eGFR. Intrapatient MPA trough level CV is significantly higher than for Tac, while CV for both MPA and Tac was high. MPA trough level monitoring may be a feasible monitoring option to improve patient exposure and possibly outcomes.
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Affiliation(s)
- Ekaterina K Todorova
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada
| | - Shih-Han S Huang
- Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
| | - Marta C Kobrzynski
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada
| | - Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada.,Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.,Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada
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Dong M, Fukuda T, Cox S, de Vries MT, Hooper DK, Goebel J, Vinks AA. Population pharmacokinetic-pharmacodynamic modelling of mycophenolic acid in paediatric renal transplant recipients in the early post-transplant period. Br J Clin Pharmacol 2015; 78:1102-12. [PMID: 24837828 DOI: 10.1111/bcp.12426] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Accepted: 05/12/2014] [Indexed: 11/30/2022] Open
Abstract
AIM The purpose of this study was to develop a population pharmacokinetic and pharmacodynamic (PK-PD) model for mycophenolic acid (MPA) in paediatric renal transplant recipients in the early post-transplant period. METHODS A total of 214 MPA plasma concentrations-time data points from 24 patients were available for PK model development. In 17 out of a total of 24 patients, inosine monophosphate dehydrogenase (IMPDH) enzyme activity measurements (n = 97) in peripheral blood mononuclear cells were available for PK-PD modelling. The PK-PD model was developed using non-linear mixed effects modelling sequentially by 1) developing a population PK model and 2) incorporating IMPDH activity into a PK-PD model using post hoc Bayesian PK parameter estimates. Covariate analysis included patient demographics, co-medication and clinical laboratory data. Non-parametric bootstrapping and prediction-corrected visual predictive checks were performed to evaluate the final models. RESULTS A two compartment model with a transit compartment absorption best described MPA PK. A non-linear relationship between dose and MPA exposure was observed and was described by a power function in the model. The final population PK parameter estimates (and their 95% confidence intervals) were CL/F, 22 (14.8, 25.2) l h(-1) 70 kg(-1) ; Vc /F, 45.4 (29.6, 55.6) l; Vp /F, 411 (152.6, 1472.6)l; Q/F, 22.4 (16.0, 32.5) l h(-1) ; Ka , 2.5 (1.45, 4.93) h(-1) . Covariate analysis in the PK study identified body weight to be significantly correlated with CL/F. A simplified inhibitory Emax model adequately described the relationship between MPA concentration and IMPDH activity. The final population PK-PD parameter estimates (and their 95% confidence intervals) were: E0 , 3.45 (2.61, 4.56) nmol h(-1) mg(-1) protein and EC50 , 1.73 (1.16, 3.01) mg l(-1) . Emax was fixed to 0. There were two African-American patients in our study cohorts and both had low IMPDH baseline activities (E0 ) compared with Caucasian patients (mean value 2.13 mg l(-1) vs. 3.86 mg l(-1) ). CONCLUSION An integrated population PK-PD model of MPA has been developed in paediatric renal transplant recipients. The current model provides information that will facilitate future studies and may be implemented in a Bayesian algorithm to allow a PK-PD guided therapeutic drug monitoring strategy.
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Affiliation(s)
- Min Dong
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
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Effects of unbound mycophenolic acid on inosine monophosphate dehydrogenase inhibition in pediatric kidney transplant patients. Ther Drug Monit 2015; 36:716-23. [PMID: 24739663 DOI: 10.1097/ftd.0000000000000081] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mycophenolic acid (MPA) is a key immunosuppressive drug that acts through inhibition of inosine monophosphate dehydrogenase (IMPDH). MPA is commonly measured, as part of therapeutic drug monitoring, as the total concentration in plasma. However, it has been postulated that the free (unbound) fraction of MPA (fMPA) is responsible for the immunosuppressive effects. In this study, a sensitive low volume high-performance liquid chromatography (HPLC) assay was developed to measure fMPA concentrations to explore the relationship between fMPA and IMPDH activity. METHODS To obtain fMPA concentrations, plasma samples were filtrated using Centrifree ultrafiltration devices. The ultrafiltrate was analyzed by HPLC using a Kinetex C18 column (2.6 μm, 3.0 × 75 mm). fMPA concentrations were compared with the total MPA concentrations available in 28 pediatric kidney transplant patients at 3 consecutive occasions after transplantation. The relationship between fMPA and IMPDH activity was analyzed using an Emax model. RESULTS The HPLC assay, using 25 μL of the ultrafiltrates, was validated over a range from 2.5 to 1000 μL with good accuracy, precision, and reproducibility. Total and free MPA concentrations were well correlated (R = 0.85, P < 0.0001), although large intraindividual and interindividual variability in the bound MPA fractions was observed. The overall relationship between fMPA concentrations and IMPDH inhibition using the Emax model was comparable with that of total MPA, as previously reported. The model estimated EC50 value (164.5 μL) is in good agreement with reported in vitro EC50 values. CONCLUSIONS This study provides a simple HPLC method for the measurement of fMPA and a pharmacologically reasonable EC50 estimate. The good correlation between the total and free MPA concentrations suggests that routine measurement of fMPA to characterize mycophenolate pharmacokinetic and pharmacodynamic does not seem warranted, although the large variability in the bound fractions of MPA warrants further study.
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Sobiak J, Resztak M, Ostalska-Nowicka D, Zachwieja J, Gąsiorowska K, Piechanowska W, Chrzanowska M. Monitoring of mycophenolate mofetil metabolites in children with nephrotic syndrome and the proposed novel target values of pharmacokinetic parameters. Eur J Pharm Sci 2015; 77:189-96. [PMID: 26102431 DOI: 10.1016/j.ejps.2015.06.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 05/22/2015] [Accepted: 06/19/2015] [Indexed: 11/30/2022]
Abstract
The aim of the study was to estimate target values of mycophenolate mofetil (MMF) pharmacokinetic parameters in children with proteinuric glomerulopathies by calculating the pharmacokinetic parameters of MMF metabolites (mycophenolic acid [MPA], free MPA [fMPA] and MPA glucuronide [MPAG]) and assessing their relation to proteinuria recurrence. One hundred and sixty-eight blood samples were collected from children, aged 3-18 years, diagnosed with nephrotic syndrome or lupus nephritis. MMF metabolites concentrations were examined before drug administration (Ctrough) and up to 12h afterward employing high-performance liquid chromatography. Dose-normalized MPA Ctrough and area under the concentration-time curve from 0 to 12h (AUC12) were within 0.29-6.47 μg/mL/600 mg/m(2) and 9.97-105.52 μg h/mL/600 mg/m(2), respectively. MPA Ctrough was twofold lower (p=0.024) in children with proteinuria recurrence. MPA, fMPA and MPAG concentrations correlated positively to respective AUC12. It may be suggested MMF metabolites monitoring in children with proteinuric glomerulopathies is justified by MPA Ctrough<2 μg/mL in patients at risk of the proteinuria recurrence. Such a recurrence is most probably caused by not sufficient MPA concentration during proteinuric glomerulopathies treatment. MPA Ctrough>3 μg/mL may be considered as an efficient one to avoid proteinuria recurrence. Finally, MPA target AUC12 should exceed 60 μg h/mL to ensure the safe and effective treatment in children with nephrotic syndrome, however, the upper limit is still to be established.
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Affiliation(s)
- Joanna Sobiak
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781 Poznan, Poland.
| | - Matylda Resztak
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781 Poznan, Poland
| | - Danuta Ostalska-Nowicka
- Department of Pediatric Cardiology and Nephrology, Poznan University of Medical Sciences, 27/33 Szpitalna Street, 60-572 Poznan, Poland
| | - Jacek Zachwieja
- Department of Pediatric Cardiology and Nephrology, Poznan University of Medical Sciences, 27/33 Szpitalna Street, 60-572 Poznan, Poland
| | - Karolina Gąsiorowska
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781 Poznan, Poland
| | - Wiktoria Piechanowska
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781 Poznan, Poland
| | - Maria Chrzanowska
- Department of Physical Pharmacy and Pharmacokinetics, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781 Poznan, Poland
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36
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Therapeutic drug monitoring in pediatric renal transplantation. Pediatr Nephrol 2015; 30:253-65. [PMID: 24763544 DOI: 10.1007/s00467-014-2813-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/14/2014] [Accepted: 03/14/2014] [Indexed: 10/25/2022]
Abstract
Finding the balance between clinical efficacy and toxicity of immunosuppressive drugs is a challenge in renal transplantation (RTx), but especially in pediatric RTx patients. Due to the expected longer life-span of pediatric transplant patients and the long-term consequences of drug-induced infectious, malignant and cardiovascular adverse effects, protocols which minimize immunosuppressive therapy make conceptual sense. In this context, therapeutic drug monitoring is a tool which provides support for the individualization of therapy. It has, however, limitations, and specific data in the pediatric cohort are comparatively sparse. There is large heterogeneity among the studies conducted to date in terms of methods, follow-up, endpoints, immunosuppressive regimens and patients. In addition, data from adult studies are not readily transferrable to the pediatric situation. This educational review gives a concise overview on aspects of therapeutic drug monitoring in pediatric RTx.
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Pan H, Gazarian A, Fourier A, Gagnieu MC, Leveneur O, Sobh M, Michallet MC, Buff S, Roger T, Dubernard JM, Michallet M. Short-term pharmacokinetic study of mycophenolate mofetil in neonatal swine. Transplant Proc 2014; 46:3620-8. [PMID: 25498100 DOI: 10.1016/j.transproceed.2014.08.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 08/19/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Mycophenolate mofetil (MMF) is an effective immunosuppressive agent that has been frequently used in laboratory animals including swine; however, the pharmacokinetic properties of MMF in swine have not been studied. This short-term study was designed to evaluate the feasibility and the pharmacokinetic profiles of MMF therapy in neonatal swine. MATERIALS AND METHODS Twelve neonatal pigs were randomized into four groups including one control and three treated groups with oral MMF administered at 0.5, 1, and 2 g/m(2)/d for 4 days, divided by 2 half-doses at 9:00 and 17:00 (except day 4 during which MMF was not administered at 17:00). Blood samples were collected at 9:00 on days 0, 2, 3 and 4 for complete blood count and hepatic/renal function examination; the trough concentration of plasma mycophenolic acid (MPA) was also determined. On days 2 and 4, blood was collected to determine the area under the curve (AUC) of plasma MPA concentration. Animal body-weight growth and manifestations of MMF side-effects such as anorexia, vomiting, and diarrhea were also observed. RESULTS MMF has no acute hepatic/renal toxicity in newborn pigs; however, less body-weight growth was observed in treated groups. In the control group, a spontaneous increase of lymphocyte count was observed; in contrast, MMF therapy with doses of 1 and 2 g/m(2)/d reduced both lymphocyte and monocyte counts of piglets. Oral MMF had high bioavailability in neonatal swine. MPA-AUC0-12h of doses 0.5, 1, and 2 g/m(2)/d was 22.00 ± 3.32, 57.57 ± 34.30, and 140.00 ± 19.70 μg × h/mL, respectively. Neither MPA trough concentration (MPA-C0), nor MPA maximum concentration (MPA-Cmax) or MPA-AUC0-6h had high correlation with MMF-dose. For surveillance of MPA exposure, MPA-C0 had significant correlation with MPA-AUC0-12h (Spearman's ρ = 0.933, AUC0-12h = 17.882 × C0 + 14.479, r(2) = 0.966). CONCLUSION To reach adequate drug exposure and to reduce dose-dependent side effects, an MMF dose of 1 g/m(2)/d is recommended to be used as an initial dose for immunosuppressive therapy in piglets, and MPA-C0 monitoring is the most practical strategy for experimental transplantation study.
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Affiliation(s)
- H Pan
- Department of Transplantation, Hôpital Edouard Herriot, Lyon, France; Université de Lyon, VetAgro Sup, UPSP ICE 2011-03-101 'Interactions Cellules Environnement', Veterinary Campus of Lyon, Marcy l'Etoile, France
| | - A Gazarian
- Hand Surgery Department, Clinique du Parc, Lyon, France
| | - A Fourier
- Laboratory of Pharmacology, Hôpital Edouard Herriot, Lyon, France
| | - M-C Gagnieu
- Laboratory of Pharmacology, Hôpital Edouard Herriot, Lyon, France
| | - O Leveneur
- Institut Claude Bourgelat, VetAgro Sup-Campus Vétérinaire de Lyon, Marcy l'Etoile, France
| | - M Sobh
- Department of Hematology, Centre Hospitalier Lyon-Sud, Pierre Benite, France
| | - M-C Michallet
- Cancer Research Center Lyon (CRCL), UMR INSERM 1052 CNRS 5286, Centre Leon Berard, Lyon, France
| | - S Buff
- Université de Lyon, VetAgro Sup, UPSP ICE 2011-03-101 'Interactions Cellules Environnement', Veterinary Campus of Lyon, Marcy l'Etoile, France
| | - T Roger
- Université de Lyon, VetAgro Sup, UPSP ICE 2011-03-101 'Interactions Cellules Environnement', Veterinary Campus of Lyon, Marcy l'Etoile, France
| | - J-M Dubernard
- Department of Transplantation, Hôpital Edouard Herriot, Lyon, France
| | - M Michallet
- Department of Hematology, Centre Hospitalier Lyon-Sud, Pierre Benite, France.
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Farina A, Delhaye M, Lescuyer P, Dumonceau JM. Bile proteome in health and disease. Compr Physiol 2014; 4:91-108. [PMID: 24692135 DOI: 10.1002/cphy.c130016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The study of bile proteins could improve the understanding of physiological processes involved in the regulation of the hepato-biliary system. Researchers have tried for years to investigate the bile proteome but, until recently, only a few tens of proteins were known. The advent of proteomics, availing of large-scale analytical devices paired with potent bioinformatic resources, lately allowed the identification of thousands of proteins in bile. Nevertheless, the knowledge of their role in the hepato-biliary system still represents almost a "blank page in the book of physiology." In this review, we first guide the reader through the historical phases of the analysis of bile protein content, emphasizing the recent progresses achieved through the use of proteomic techniques. Thereafter, we deeply explore the involvement of bile proteins in health and disease, with a particular focus on the discovery of biomarkers for biliary tract malignancies.
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Affiliation(s)
- Annarita Farina
- Biomedical Proteomics Research Group, Department of Human Protein Sciences, Geneva University, Geneva, Switzerland
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Affiliation(s)
- Guido Filler
- Department of Pediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada, N6A 5W9; Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada, N5A 5A5; Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada, N5A 5A5.
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González-Ramírez R, González-Bañuelos J, Villa MDLS, Jiménez B, García-Roca P, Cruz-Antonio L, Castañeda-Hernández G, Medeiros M. Bioavailability of a generic of the immunosuppressive agent mycophenolate mofetil in pediatric patients. Pediatr Transplant 2014; 18:568-74. [PMID: 24978101 DOI: 10.1111/petr.12311] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/30/2014] [Indexed: 12/18/2022]
Abstract
The use of generic immunosuppressive agents is controversial, especially for the treatment of pediatric patients, as information on the bioavailability of generic immunosuppressants in children is particularly scarce. The aim of the study was to compare the bioavailabilities of two products containing mycophenolate mofetil, the innovator and a generic, in children. Pediatric patients with end-stage renal disease on the waiting list for renal transplantation received a single oral dose of mycophenolate mofetil as either the innovator product (CellCept(®) , Roche) or the generic (Tevacept(®) , Teva Pharmaceuticals). A nine point pharmacokinetic profile was obtained. Mycophenolic acid concentration was quantitated in plasma by HPLC, plasma concentration-against-time curves were constructed, and bioavailability parameters were determined. Pharmaceutical quality analysis of both formulations, including drug content and dissolution profile, was also performed. There were no statistically significant differences between formulations in bioavailability parameters. Interindividual variability was very important, but individual values of AUC, an indicator of the extent of drug absorption, were within the same range for both formulations. The two formulations exhibited similar drug content and dissolution profiles, as well as comparable mycophenolic acid plasma levels in an end-stage renal failure population.
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Affiliation(s)
- Rodrigo González-Ramírez
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico City, Mexico
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Affiliation(s)
- Guido Filler
- Department of Paediatrics, Schulich School of Medicine & Dentistry, London, ON, Canada; Department of Pathology and Laboratory Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada; Department of Medicine, Schulich School of Medicine & Dentistry, University of Western Ontario, London, ON, Canada.
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Zhao W, Leroux S, Jacqz-Aigrain E. Dosage individualization in children: integration of pharmacometrics in clinical practice. World J Pediatr 2014; 10:197-203. [PMID: 25124969 DOI: 10.1007/s12519-014-0493-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 06/18/2014] [Indexed: 12/21/2022]
Abstract
BACKGROUND Children are in a continuous and dynamically changing state of growth and development. A thorough understanding of developmental pharmacokinetics (PK) and pharmacodynamics (PD) is required to optimize drug therapy in children. DATA SOURCES Based on recent publications and the experience of our group, we present an outline on integrating pharmacometrics in pediatric clinical practice to develop evidence-based personalized pharmacotherapy. RESULTS Antibiotics in septic neonates and immunosuppressants in pediatric transplant recipients are provided as proof-of-concept to demonstrate the utility of pharmacometrics in clinical practice. Dosage individualization based on developmental PK-PD model has potential benefits of improving the efficacy and safety of drug therapy in children. CONCLUSION The pharmacometric technique should be better developed and used in clinical practice to personalize drug therapy in children in order to decrease variability of drug exposure and associated risks of overdose or underdose.
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Affiliation(s)
- Wei Zhao
- Department of Clinical Pharmacy, School of Pharmaceutical Sciences, Shandong University, Jinan, 250012, China,
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Abstract
INTRODUCTION To discuss the significance of the recent observational case series from the Swiss Toxicological Information Centre (STIC). Mycophenolic acid (MPA) and its prodrug mycophenolate mofetil are immunosuppressive agents that are frequently prescribed in renal transplant recipients, and their safety profiles must be established. AREAS COVERED This case series and systemic literature analysis consists of 15 cases of MPA overdose from the STIC and a systemic analysis of the literature over the past 18 years. This study focuses on acute overdosing, the effects of which are presumably mild. In contrast, the effects of long-term overdosing may be much more severe. Substantial underreporting is likely. The pharmacokinetic monitoring of MPA is rarely performed, which is both striking and does not coincide with findings in academic literature. The scant data on pharmacokinetic monitoring presented demonstrated that MPA has a short terminal half-life, which suggests that decontamination and activated charcoal treatment in acute overdose may not be necessary. EXPERT OPINION The case series and systematic literature analysis of acute mycophenolate overdose represent an important contribution toward increasing the safety of MPA therapy.
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Affiliation(s)
- Guido Filler
- University of Western Ontario, Children's Hospital, Schulich School of Medicine & Dentistry, London Health Sciences Centre, Department of Paediatrics , 800 Commissioners Road East, London, ON N6A 5W9 , Canada
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Abstract
Solid organ transplantation has transformed the lives of many children and adults by providing treatment for patients with organ failure who would have otherwise succumbed to their disease. The first successful transplant in 1954 was a kidney transplant between identical twins, which circumvented the problem of rejection from MHC incompatibility. Further progress in solid organ transplantation was enabled by the discovery of immunosuppressive agents such as corticosteroids and azathioprine in the 1950s and ciclosporin in 1970. Today, solid organ transplantation is a conventional treatment with improved patient and allograft survival rates. However, the challenge that lies ahead is to extend allograft survival time while simultaneously reducing the side effects of immunosuppression. This is particularly important for children who have irreversible organ failure and may require multiple transplants. Pediatric transplant teams also need to improve patient quality of life at a time of physical, emotional and psychosocial development. This review will elaborate on the long-term outcomes of children after kidney, liver, heart, lung and intestinal transplantation. As mortality rates after transplantation have declined, there has emerged an increased focus on reducing longer-term morbidity with improved outcomes in optimizing cardiovascular risk, renal impairment, growth and quality of life. Data were obtained from a review of the literature and particularly from national registries and databases such as the North American Pediatric Renal Trials and Collaborative Studies for the kidney, SPLIT for liver, International Society for Heart and Lung Transplantation and UNOS for intestinal transplantation.
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Affiliation(s)
- Jon Jin Kim
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, England, United Kingdom
| | - Stephen D Marks
- Department of Pediatric Nephrology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, England, United Kingdom
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UGT1A9, UGT2B7, and MRP2 genotypes can predict mycophenolic acid pharmacokinetic variability in pediatric kidney transplant recipients. Ther Drug Monit 2013; 34:671-9. [PMID: 23131697 DOI: 10.1097/ftd.0b013e3182708f84] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mycophenolic acid (MPA) exposure in pediatric patients with kidney transplant receiving body surface area (BSA)-based dosing exhibits large variability. Several genetic variants in glucuronosyltransferases (UGTs) and of multidrug resistance-associated protein 2 (MRP2) have independently been suggested to predict MPA exposure in adult patients with varying results. Here, the combined contribution of these genetic variants to MPA pharmacokinetic variability was investigated in pediatric renal transplant recipients who were on mycophenolic mofetil maintenance therapy. METHODS MPA and MPA-glucuronide concentrations from 32 patients were quantified by high-performance liquid chromatography. MPA exposure (AUC) was estimated using a 4-point abbreviated sampling strategy (predose/trough and 20 minutes, 1 hour, and 3 hours after dose) using a validated pediatric Bayesian estimator. Genotyping was performed for all of the following single nucleotide polymorphisms (SNPs): UGT1A8 830G>A(*3), UGT1A9 98T>C(*3), UGT1A9-440C>T, UGT1A9-2152C>T, UGT1A9-275T>A, UGT2B7-900A>G, and MRP2-24T>C. RESULTS Recipients heterozygous for MRP2-24T>C who also had UGT1A9-440C>T or UGT2B7-900A>G (n = 4), and MRP2-24T>C-negative recipients having both UGT1A9-440C>T and UGT2B7-900A>G (n = 5) showed a 2.2 and 1.7 times higher dose-dependent and BSA-normalized MPA-AUC compared with carriers of no or only 1 UGT-SNP (P < 0.001 and P = 0.01, respectively) (n = 7). Dose-dependent and BSA-normalized predose MPA concentrations were 3.0 and 2.4 times higher, respectively (P < 0.001). Interindividual variability in peak concentrations could be explained by the presence of the UGT1A9-440C>T genotype (P < 0.05). CONCLUSION Our preliminary study demonstrates that combined UGT1A9-440C>T, UGT2B7-900A>G, and MRP2-24T>C polymorphisms can be important predictors of interindividual variability in MPA exposure in the pediatric population.
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Barau C, Furlan V, Debray D, Taburet AM, Barrail-Tran A. Population pharmacokinetics of mycophenolic acid and dose optimization with limited sampling strategy in liver transplant children. Br J Clin Pharmacol 2013; 74:515-24. [PMID: 22329639 DOI: 10.1111/j.1365-2125.2012.04213.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
AIMS The aims were to estimate the mycophenolic acid (MPA) population pharmacokinetic parameters in paediatric liver transplant recipients, to identify the factors affecting MPA pharmacokinetics and to develop a limited sampling strategy to estimate individual MPA AUC(0,12 h). METHODS Twenty-eight children, 1.1 to 18.0 years old, received oral mycophenolate mofetil (MMF) therapy combined with either tacrolimus (n= 23) or ciclosporin (n= 5). The population parameters were estimated from a model-building set of 16 intensive pharmacokinetic datasets obtained from 16 children. The data were analyzed by nonlinear mixed effect modelling, using a one compartment model with first order absorption and first order elimination and random effects on the absorption rate (k(a)), the apparent volume of distribution (V/F) and apparent clearance (CL/F). RESULTS Two covariates, time since transplantation (≤ and >6 months) and age affected MPA pharmacokinetics. k(a), estimated at 1.7 h(-1) at age 8.7 years, exhibited large interindividual variability (308%). V/F, estimated at 64.7 l, increased about 2.3 times in children during the immediate post transplantation period. This increase was due to the increase in the unbound MPA fraction caused by the low albumin concentration. CL/F was estimated at 12.7 l h(-1). To estimate individual AUC(0,12 h), the pharmacokinetic parameters obtained with the final model, including covariates, were coded in Adapt II(®) software, using the Bayesian approach. The AUC(0,12 h) estimated from concentrations measured 0, 1 and 4 h after administration of MMF did not differ from reference values. CONCLUSIONS This study allowed the estimation of the population pharmacokinetic MPA parameters. A simple sampling procedure is suggested to help to optimize pediatric patient care.
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Affiliation(s)
- Caroline Barau
- Department of Clinical Pharmacy, Assistance Publique - Hôpitaux de Paris, Hôpitaux Universitaires Paris-Sud, Le Kremlin Bicêtre, France
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Downing HJ, Pirmohamed M, Beresford MW, Smyth RL. Paediatric use of mycophenolate mofetil. Br J Clin Pharmacol 2013; 75:45-59. [PMID: 22519685 PMCID: PMC3555046 DOI: 10.1111/j.1365-2125.2012.04305.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 04/16/2012] [Indexed: 01/14/2023] Open
Abstract
A number of medications do not have a licence, or label, for use in the paediatric age group nor for the specific indication for which they are being used in children. Over recent years, mycophenolate mofetil has increasingly been used off-label (i.e. off-licence) in adults for a number of indications, including autoimmune conditions; progressively, this wider use has been extended to children. This review summarizes current use of mycophenolate mofetil (MMF) in children, looking at how MMF works, the pharmacokinetics, the clinical conditions for which it is used, the advantages it has when compared with other immunosuppressants and the unresolved issues remaining with use in children. The review aims to focus on off-label use in children so as to identify areas that require further research and investigation. The overall commercial value of MMF is limited because it has now come off patent in adults. Given the increasing knowledge of the pharmacodynamics, pharmacokinetics and pharmacogenomics demonstrating the clinical benefits of MMF, new, formal, investigator-led studies, including trials focusing on the use of MMF in children, would be of immense value.
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Affiliation(s)
- Heather J Downing
- Department of Women's and Children's Health, Institute of Translational Medicine, The University of Liverpool, Alder Hey Children's NHS Foundation TrustEaton Road, Liverpool L12 2AP, UK
| | - Munir Pirmohamed
- Department of Pharmacology and Therapeutics, The University of LiverpoolAshton Street, Liverpool L69 3GE, UK
| | - Michael W Beresford
- Department of Women's and Children's Health, Institute of Translational Medicine, The University of Liverpool, Alder Hey Children's NHS Foundation TrustEaton Road, Liverpool L12 2AP, UK
| | - Rosalind L Smyth
- Department of Women's and Children's Health, Institute of Translational Medicine, The University of Liverpool, Alder Hey Children's NHS Foundation TrustEaton Road, Liverpool L12 2AP, UK
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