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Heida A, Jager NGL, Aarnoutse RE, de Winter BCM, de Jong H, Keizer RJ, Cornelissen EAM, Ter Heine R. Model-informed dose optimization of mycophenolic acid in pediatric kidney transplant patients. Eur J Clin Pharmacol 2024; 80:1761-1771. [PMID: 39153087 PMCID: PMC11458656 DOI: 10.1007/s00228-024-03743-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Accepted: 08/09/2024] [Indexed: 08/19/2024]
Abstract
PURPOSE We aimed to develop and evaluate a population PK model of mycophenolic acid (MPA) in pediatric kidney transplant patients to aid MPA dose optimization. METHODS Data were collected from pediatric kidney transplant recipients from a Dutch academic hospital (Radboudumc, the Netherlands). Pharmacokinetic model-building and model-validation analyses were performed using NONMEM. Subsequently, we externally evaluated the final model using data from another academic hospital. The final model was used to develop an optimized dosing regimen. RESULTS Thirty pediatric patients were included of whom 266 measured MPA plasma concentrations, including 20 full pharmacokinetic (PK) curves and 24 limited sampling curves, were available. A two-compartment model with a transition compartment for Erlang-type absorption best described the data. The final population PK parameter estimates were Ktr (1.48 h-1; 95% CI, 1.15-1.84), CL/F (16.0 L h-1; 95% CI, 10.3-20.4), Vc/F (24.9 L; 95% CI, 93.0-6.71E25), Vp/F (1590 L; 95% CI, 651-2994), and Q/F (36.2 L h-1; 95% CI, 9.63-74.7). The performance of the PK model in the external population was adequate. An optimized initial dose scheme based on bodyweight was developed. With the licensed initial dose, 35% of patients were predicted to achieve the target AUC, compared to 42% using the optimized scheme. CONCLUSION We have successfully developed a pharmacokinetic model for MPA in pediatric renal transplant patients. The optimized dosing regimen is expected to result in better target attainment early in treatment. It can be used in combination with model-informed follow-up dosing to further individualize the dose when PK samples become available.
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Affiliation(s)
- Astrid Heida
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Nynke G L Jager
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rob E Aarnoutse
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Brenda C M de Winter
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Huib de Jong
- The Erasmus MC Transplant Institute, Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | - Elisabeth A M Cornelissen
- Department of Pediatric Nephrology, Radboud University Medical Center, Amalia Children's Hospital, Nijmegen, The Netherlands
| | - Rob Ter Heine
- Department of Pharmacy, Radboud Institute for Medical Innovation, Radboud University Medical Center, Nijmegen, The Netherlands
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Park HJ, Hong KT, Han N, Kim IW, Oh JM, Kang HJ. Body Surface Area-Based Dosing of Mycophenolate Mofetil in Pediatric Hematopoietic Stem Cell Transplant Recipients: A Prospective Population Pharmacokinetic Study. Pharmaceutics 2023; 15:2741. [PMID: 38140082 PMCID: PMC10748085 DOI: 10.3390/pharmaceutics15122741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/03/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023] Open
Abstract
Mycophenolate mofetil (MMF) is commonly used for acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). However, limited population pharmacokinetic (PPK) data are available for pediatric HSCT patients. This study aimed to develop a PPK model and recommend optimal oral MMF dosage in pediatric HSCT patients. This prospective study involved pediatric HSCT patients at a tertiary academic institution. Patients received oral MMF 15-20 mg/kg twice daily for aGVHD prophylaxis and treatment. The PPK analysis was conducted using a nonlinear mixed-effects modeling method. Simulation was performed considering different body surface areas (BSAs) (0.5 m2, 1.0 m2, 1.5 m2) and dosing (400 mg/m2, 600 mg/m2, 900 mg/m2 twice daily). Based on the simulation, an optimal dosage of oral MMF was suggested. A total of 20 patients and 80 samples were included in the PPK model development. A one-compartment model with first-order absorption adequately described the pharmacokinetics of mycophenolic acid (MPA). BSA was a statistically significant covariate on Vd/F. Simulation suggested the optimal dosage of oral MMF as 900 mg/m2 twice daily, respectively. A reliable PPK model was developed with good predictive performance. This model-informed optimal MMF dosage in pediatric HSCT patients can provide valuable dosing guidance in real-world clinical practice.
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Affiliation(s)
- Hyun Jin Park
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea; (H.J.P.); (N.H.); (I.-W.K.)
| | - Kyung Taek Hong
- Department of Pediatrics, Seoul National University College of Medicine, Seoul National University Cancer Research Institute, Seoul National University Children’s Hospital, Seoul 03080, Republic of Korea;
| | - Nayoung Han
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea; (H.J.P.); (N.H.); (I.-W.K.)
- College of Pharmacy, Jeju National University, Jeju 63243, Republic of Korea
| | - In-Wha Kim
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea; (H.J.P.); (N.H.); (I.-W.K.)
| | - Jung Mi Oh
- College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 08826, Republic of Korea; (H.J.P.); (N.H.); (I.-W.K.)
| | - Hyoung Jin Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul National University Cancer Research Institute, Seoul National University Children’s Hospital, Seoul 03080, Republic of Korea;
- Wide River Institute of Immunology, Hongcheon 25159, Republic of Korea
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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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Rong Y, Kiang T. Clinical Evidence on the Purported Pharmacokinetic Interactions between Corticosteroids and Mycophenolic Acid. Clin Pharmacokinet 2023; 62:157-207. [PMID: 36848031 DOI: 10.1007/s40262-023-01212-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2023] [Indexed: 03/01/2023]
Abstract
Corticosteroids (steroids) are commonly used concurrently with mycophenolic acid (MPA) as the first-line immunosuppression therapy for the prevention of rejection in solid organ transplantations. Steroids are also commonly administered with MPA in various autoimmune disorders such as systemic lupus erythematosus and idiopathic nephrotic syndrome. Despite various review articles having suggested the presence of pharmacokinetic interactions between MPA and steroids, definitive data have not yet been demonstrated. The aim of this Current Opinion is to critically evaluate the available clinical data and propose the optimal study design for characterising the MPA-steroid pharmacokinetic interactions. The PubMed and Embase databases were searched for relevant clinical articles in English as of September 29, 2022, where a total of 8 papers have been identified as supporting and 22 as non-supporting the purported drug interaction. To objectively evaluate the data, novel assessment criteria to effectively diagnose the interaction based on known MPA pharmacology were formulated, including the availability of independent control groups, prednisolone concentrations, MPA metabolite data, unbound MPA concentrations, and the characterisations of entero-hepatic recirculation and MPA renal clearance. Overall, the majority of the identified corticosteroid data were pertaining to prednisone or prednisolone. Our assessment indicated that no conclusive mechanistic data supporting the interaction are available in the current clinical literature, and further studies are required to quantify the effects/mechanisms of steroid-tapering or withdrawal on MPA pharmacokinetics. This current opinion provides justification for further translational investigations, as this particular drug interaction has the potential to exert significant adverse outcomes in patients prescribed MPA.
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Affiliation(s)
- Yan Rong
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Katz Group Centre for Pharmacy and Health Research, Room 3-142D, 11361-87 Avenue, Edmonton, AB, T6G 2E1, Canada
| | - Tony Kiang
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Katz Group Centre for Pharmacy and Health Research, Room 3-142D, 11361-87 Avenue, Edmonton, AB, T6G 2E1, Canada.
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Nanga TM, Woillard JB, Rousseau A, Marquet P, Prémaud A. Population Pharmacokinetics And Bayesian Estimation of Mycophenolate Mofetil In Patients With Autoimmune Hepatitis. Br J Clin Pharmacol 2022; 88:4732-4741. [PMID: 35514220 DOI: 10.1111/bcp.15389] [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: 10/25/2021] [Revised: 03/15/2022] [Accepted: 04/25/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Mycophenolate mofetil (MMF) is the most widely used second-line agent in auto-immune hepatitis (AIH). Individual dose adjustment of MMF may avoid adverse outcomes while maximizing efficacy. The aim of the present study was to develop population pharmacokinetic (popPK) models and Maximum A-Posteriori Bayesian estimators (MAP-BEs) to estimate MPA inter-dose area under the curve (AUC0-12h ) in AIH patients administered MMF using nonlinear mixed effect modelling. METHODS We analyzed 50 MPA PK profiles from 34 different patients, together with some demographic, clinical, and laboratory test data. The median number of plasma samples per profile, immediately preceding and following the morning MMF dose, was 7 [4 - 10]. PopPK modeling was performed using parametric, top-down, nonlinear mixed effect modelling with NONMEM 7.3. MAP-BEs were developed based on the best popPK model and the best limited sampling strategy (LSS) selected among several. RESULTS The pharmacokinetic data were best described by a 2-compartment model, Erlang distribution to describe the absorption phase, and a proportional error. The mean (RSE) of popPK parameter estimates of clearance, intercompartmental clearance, central volume and absorption rate with the final model were: 21.6 L.h-1 (11%), 22.7 L.h-1 (19%), 35.9 L (21%) and 8.7 h-1 (9%), respectively. The peripheral volume was fixed to 300 L. The best MAP-BE relied on the LSS at 0.33, 1 and 3 hours after mycophenolate mofetil dose administration and was very accurate (bias=5.6%) and precise (RMSE<20%). CONCLUSION The precise and accurate Bayesian estimator developed in this study for AIH patients on MMF can be used to improve the therapeutic management of these patients.
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Affiliation(s)
- Tom M Nanga
- Pharmacology & Transplantation, UMR1248, INSERM, University of Limoges, Limoges, France
| | - Jean-Baptiste Woillard
- Pharmacology & Transplantation, UMR1248, INSERM, University of Limoges, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, University Hospital of Limoges, Limoges, France
| | - Annick Rousseau
- Pharmacology & Transplantation, UMR1248, INSERM, University of Limoges, Limoges, France
| | - Pierre Marquet
- Pharmacology & Transplantation, UMR1248, INSERM, University of Limoges, Limoges, France.,Department of Pharmacology, Toxicology and Pharmacovigilance, University Hospital of Limoges, Limoges, France
| | - Aurélie Prémaud
- Pharmacology & Transplantation, UMR1248, INSERM, University of Limoges, Limoges, France
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Beaulieu Q, Zhang D, Melki I, Baudouin V, Goldwirst L, Woillard JB, Jacqz-Aigrain E. Pharmacokinetics of mycophenolic acid and external evaluation of two limited sampling strategies of drug exposure in patients with juvenile systematic lupus erythematosus. Eur J Clin Pharmacol 2022; 78:1003-1010. [PMID: 35294622 DOI: 10.1007/s00228-022-03295-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 02/14/2022] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Mycophenolate mofetil (MMF), a pro-drug of mycophenolic acid (MPA), has become a major therapeutic option in juvenile systemic lupus erythematosus (jSLE). Monitoring MPA exposure using area under curve (AUC) has proved its value to increase efficacy and safety in solid organ transplantation both in children and adults, but additional data are required in patients with autoimmune diseases. In order to facilitate MMF therapeutic drug monitoring (TDM) in children, Bayesian estimators (BE) of MPA AUC0-12 h using limited sampling strategies (LSS) have been developed. Our aim was to conduct an external validation of these LSS using rich pharmacokinetics and compare their predictive performance. METHODS Pharmacokinetic blood samples were collected from jSLE treated by MMF and MPA plasma concentrations were determined using high-performance liquid chromatography system with ultraviolet detection (HPLC-UV). Individual AUC0-12 h at steady state was calculated using the trapezoid rule and compared with two LSS: (1) ISBA, a two-stage Bayesian approach developed for jSLE and (2) ADAPT, a non-linear mixed effects model with a parametric maximum likelihood approach developed with data from renal transplanted adults. RESULTS We received 41 rich pediatric PK at steady state from jSLE and calculated individual AUC0-12 h. The external validation MPA AUC0-12 h was conducted by selecting the concentration-time points adapted to ISBA and ADAPT: (1) ISBA showed good accuracy (bias: - 0.8 mg h/L), (2) ADAPT resulted in a bias of 6.7 mg L/h. The corresponding relative root mean square prediction error (RSME) was 23% and 43% respectively. CONCLUSION According to our external validation of two LSS of drug exposure, the ISBA model is recommended for Bayesian estimation of MPA AUC0-12 h in jSLE. In the literature focusing on MMF TDM, an efficacy cut-off for MPA AUC0-12 h between 30 and 45 mg h/L is proposed in jSLE but this requires additional validation.
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Affiliation(s)
- Quentin Beaulieu
- Paediatric Pharmacology, Department of Biological Pharmacology, Saint-Louis University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Daolun Zhang
- Paediatric Pharmacology, Department of Biological Pharmacology, Saint-Louis University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Isabelle Melki
- General Pediatrics, Infectious Disease and Internal Medicine Department, Robert Debre University Hospital, Reference Center for Rheumatic, AutoImmune and Systemic Diseases in Children (RAISE), AP-HP, Paris, France.,Pediatric Hematology-Immunology and Rheumatology Department, Necker-Enfants Malades University Hospital, Reference center for Rheumatic, AutoImmune and Systemic Diseases in Children (RAISE), AP-HP, Paris, France.,Laboratory of Neurogenetics and Neuroinflammation, Imagine Institute, Paris, France
| | - Véronique Baudouin
- Department of Pediatric Nephrology, Robert Debré University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Lauriane Goldwirst
- Paediatric Pharmacology, Department of Biological Pharmacology, Saint-Louis University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France
| | - Jean-Baptiste Woillard
- IPPRITT, INSERM, U1248, Limoges, France.,IPPRITT, University of Limoges, Limoges, France.,Department of Pharmacology and Toxicology, CHU Limoges, Limoges, France
| | - Evelyne Jacqz-Aigrain
- Paediatric Pharmacology, Department of Biological Pharmacology, Saint-Louis University Hospital, Assistance Publique - Hôpitaux de Paris, Paris, France. .,University of Paris, Paris, France. .,Department of Biological Pharmacology, Saint-Louis University Hospital, Assistance Publique - Hôpitaux de Paris, FranceHôpital Saint-Louis, Assistance Publique Hôpitaux de Paris, 1 avenue Charles Vellefaux, Paris, 75010, France.
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Rong Y, Patel V, Kiang TKL. Recent lessons learned from population pharmacokinetic studies of mycophenolic acid: physiological, genomic, and drug interactions leading to the prediction of drug effects. Expert Opin Drug Metab Toxicol 2022; 17:1369-1406. [PMID: 35000505 DOI: 10.1080/17425255.2021.2027906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Mycophenolic acid (MPA) is a widely used immunosuppressant in transplantation and autoimmune disease. Highly variable pharmacokinetics have been observed with MPA, but the exact mechanisms remain largely unknown. AREAS COVERED The current review provided a critical, comprehensive update of recently published population pharmacokinetic/dynamic models of MPA (n=16 papers identified from PubMed and Embase, inclusive from January 2017 to August 2021), with specific emphases on the intrinsic and extrinsic factors influencing the pharmacology of MPA. The significance of the identified covariates, potential mechanisms, and comparisons to historical literature have been provided. EXPERT OPINION While select covariates affecting the population pharmacokinetics of MPA are consistently observed and mechanistically supported, some variables have not been regularly reported and/or lacked mechanistic explanation. Very few pharmacodynamic models were available, pointing to the need to extrapolate pharmacokinetic findings. Ideal models of MPA should consist of: i) utilizing optimal sampling points to allow the characterizations of absorption, re-absorption, and elimination phases; ii) characterizing unbound/total MPA, MPA metabolites, plasma/urinary concentrations, and genetic polymorphisms to facilitate mechanistic interpretations; and iii) incorporating actual outcomes and pharmacodynamic data to establish clinical relevance. We anticipate the field will continue to expand in the next 5 to 10 years.
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Affiliation(s)
- Yan Rong
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Vrunda Patel
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Tony K L Kiang
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada
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Job KM, Roberts JK, Enioutina EY, IIIamola SM, Kumar SS, Rashid J, Ward RM, Fukuda T, Sherbotie J, Sherwin CM. Treatment optimization of maintenance immunosuppressive agents in pediatric renal transplant recipients. Expert Opin Drug Metab Toxicol 2021; 17:747-765. [PMID: 34121566 PMCID: PMC10726690 DOI: 10.1080/17425255.2021.1943356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 06/11/2021] [Indexed: 10/21/2022]
Abstract
Introduction: Graft survival in pediatric kidney transplant patients has increased significantly within the last three decades, correlating with the discovery and utilization of new immunosuppressants as well as improvements in patient care. Despite these developments in graft survival for patients, there is still improvement needed, particularly in long-term care in pediatric patients receiving grafts from deceased donor patients. Maintenance immunosuppressive therapies have narrow therapeutic indices and are associated with high inter-individual and intra-individual variability.Areas covered: In this review, we examine the impact of pharmacokinetic variability on renal transplantation and its association with age, genetic polymorphisms, drug-drug interactions, drug-disease interactions, renal insufficiency, route of administration, and branded versus generic drug formulation. Pharmacodynamics are outlined in terms of the mechanism of action for each immunosuppressant, potential adverse effects, and the utility of pharmacodynamic biomarkers.Expert opinion: Acquiring abetter quantitative understanding of immunosuppressant pharmacokinetics and pharmacodynamic components should help clinicians implement treatment regimens to maintain the balance between therapeutic efficacy and drug-related toxicity.
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Affiliation(s)
- Kathleen M Job
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Jessica K Roberts
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Elena Y Enioutina
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Sílvia M IIIamola
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Shaun S Kumar
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Jahidur Rashid
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
| | - Robert M Ward
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah, Salt Lake City, UT, USA
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Tsuyoshi Fukuda
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Joseph Sherbotie
- Department of Pediatrics, School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Catherine M Sherwin
- Department of Experimental and Clinical Pharmacology, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
- Department of Pediatrics, Boonshoft School of Medicine, Dayton Children’s Hospital, Wright State University, Dayton, OH, USA
- Department of Pharmacotherapy, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
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Gao X, Wu L, Tsai RYL, Ma J, Liu X, Chow DSL, Liang D, Xie H. Pharmacokinetic Model Analysis of Supralingual, Oral and Intravenous Deliveries of Mycophenolic Acid. Pharmaceutics 2021; 13:pharmaceutics13040574. [PMID: 33920640 PMCID: PMC8072905 DOI: 10.3390/pharmaceutics13040574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 01/20/2023] Open
Abstract
Mycophenolic acid (MPA) is commonly used for organ rejection prophylaxis via oral administration in the clinic. Recent studies have shown that MPA also has anticancer activities. To explore new therapeutic options for oral precancerous/cancerous lesions, MPA was designed to release topically on the dorsal tongue surface via a mucoadhesive patch. The objective of this study was to establish the pharmacokinetic (PK) and tongue tissue distribution of mucoadhesive MPA patch formulation after supralingual administration in rats and also compare the PK differences between oral, intravenous, and supralingual administration of MPA. Blood samples were collected from Sprague Dawley rats before and after a single intravenous bolus injection, a single oral dose, or a mucoadhesive patch administration on the dorsal tongue surface for 4 h, all with a dose of 0.5 mg/kg of MPA. Plots of MPA plasma concentration versus time were obtained. As multiple peaks were found in all three curves, the enterohepatic recycling (EHR) model in the Phoenix software was adapted to describe their PK parameters with an individual PK analysis method. The mean half-lives of intravenous and oral administrations were 10.5 h and 7.4 h, respectively. The estimated bioavailability after oral and supralingual administration was 72.4% and 7.6%, respectively. There was a 0.5 h lag-time presented after supralingual administration. The results suggest that the systemic plasma MPA concentrations were much lower in rats receiving supralingual administration compared to those receiving doses from the other two routes, and the amount of MPA accumulated in the tongue after patch application showed a sustained drug release pattern. Studies on the dynamic of drug retention in the tongue after supralingual administration showed that ~3.8% of the dose was accumulated inside of tongue right after the patch removal, ~0.11% of the dose remained after 20 h, and ~20.6% of MPA was not released from the patches 4 h after application. The data demonstrate that supralingual application of an MPA patch can deliver a high amount of drug at the site of administration with little systemic circulation exposure, hence lowering the potential gastrointestinal side effects associated with oral administration. Thus, supralingual administration is a potential alternative route for treating oral lesions.
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Affiliation(s)
- Xiuqing Gao
- Department of Pharmaceutical Science, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (X.G.); (J.M.); (D.L.)
| | - Lei Wu
- Department of Pharmcological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, USA; (L.W.); (D.S.-L.C.)
| | - Robert Y. L. Tsai
- Department of Translational Medical Sciences, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA;
| | - Jing Ma
- Department of Pharmaceutical Science, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (X.G.); (J.M.); (D.L.)
| | - Xiaohua Liu
- Department of Biomedical Sciences, Baylor College of Dentistry, Dallas, TX 75246, USA;
| | - Diana S.-L. Chow
- Department of Pharmcological & Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX 77204, USA; (L.W.); (D.S.-L.C.)
| | - Dong Liang
- Department of Pharmaceutical Science, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (X.G.); (J.M.); (D.L.)
| | - Huan Xie
- Department of Pharmaceutical Science, College of Pharmacy and Health Sciences, Texas Southern University, Houston, TX 77004, USA; (X.G.); (J.M.); (D.L.)
- Correspondence: ; Tel.: +1-713-775-6235
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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: 92] [Impact Index Per Article: 30.7] [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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11
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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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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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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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Reséndiz-Galván JE, Romano-Aguilar M, Medellín-Garibay SE, Milán-Segovia RDC, Niño-Moreno PDC, Jung-Cook H, Chevaile-Ramos JA, Romano-Moreno S. Population pharmacokinetics of mycophenolic acid in adult kidney transplant patients under prednisone and tacrolimus regimen. Eur J Pharm Sci 2020; 150:105370. [DOI: 10.1016/j.ejps.2020.105370] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 12/25/2022]
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Romano-Aguilar M, Reséndiz-Galván JE, Medellín-Garibay SE, Milán-Segovia RDC, Martínez-Martínez MU, Abud-Mendoza C, Romano-Moreno S. Population pharmacokinetics of mycophenolic acid in Mexican patients with lupus nephritis. Lupus 2020; 29:1067-1077. [DOI: 10.1177/0961203320931567] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BackgroundMycophenolic acid (MPA) is an effective oral immunosuppressive drug used to treat lupus nephritis (LN), which exhibits large pharmacokinetic variability. This study aimed to characterize MPA pharmacokinetic behaviour in Mexican LN patients and to develop a population pharmacokinetic model which identified factors that influence MPA pharmacokinetic variability.MethodsBlood samples from LN patients treated with mycophenolate mofetil (MMF) were collected pre dose and up to six hours post dose. MPA concentrations were determined by a validated ultra-performance liquid chromatography tandem mass spectrometry technique. Patients were genotyped for polymorphisms in enzymes (UGT1A8, 1A9 and 2B7) and transporters (ABCC2 and SLCO1B3). The anthropometric, clinical, genetic and co-medication characteristics of each patient were considered as potential covariates to explain the variability.ResultsA total of 294 MPA concentrations from 40 LN patients were included in the development of the model. The data were analysed using NONMEM software and were best described by a two-compartment linear model. MPA CL, Vc, Vp, Ka and Q were 15.4 L/h, 22.86 L, 768 L, 1.28 h−1and 20.3 L/h, respectively. Creatinine clearance and prednisone co-administration proved to have influence on clearance, while body weight influenced Vc. The model was internally validated, proving to be stable. MMF dosing guidelines were obtained through stochastic simulations performed with the final model.ConclusionsThis is the first MPA population pharmacokinetic model to have found that co-administration of prednisone results in a considerable increase on clearance. Therefore, this and the other covariates should be taken into account when prescribing MMF in order to optimize the immunosuppressant therapy in patients with LN.
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Affiliation(s)
- Melissa Romano-Aguilar
- Pharmacy Laboratory, Faculty of Chemical Sciences, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico
| | - Juan Eduardo Reséndiz-Galván
- Pharmacy Laboratory, Faculty of Chemical Sciences, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico
| | | | - Rosa del Carmen Milán-Segovia
- Pharmacy Laboratory, Faculty of Chemical Sciences, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico
| | | | - Carlos Abud-Mendoza
- Rheumatology and Immunology Unit, Central Hospital ‘Dr. Ignacio Morones Prieto’, San Luis Potosi, Mexico
| | - Silvia Romano-Moreno
- Pharmacy Laboratory, Faculty of Chemical Sciences, Autonomous University of San Luis Potosi, San Luis Potosi, Mexico
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16
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Almardini R, Taybeh EO, Alsous MM, Hawwa AF, McKeever K, Horne R, McElnay JC. A multiple methods approach to determine adherence with prescribed mycophenolate in children with kidney transplant. Br J Clin Pharmacol 2019; 85:1434-1442. [PMID: 30845359 DOI: 10.1111/bcp.13911] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 02/07/2019] [Accepted: 02/09/2019] [Indexed: 12/22/2022] Open
Abstract
AIMS The aim of this study was, to use a multiple methods approach, including, for the first time, dried blood spot (DBS) sampling with population pharmacokinetic interpretation, to assess adherence to mycophenolate in children with kidney transplant. A second aim was to identify patient/parental factors that influenced adherence and to link adherence behaviour to clinical outcomes. METHODS A convenience sample of 33 children with kidney transplant (age ≤ 18 years) who had been prescribed mycophenolate for at least 3 months were recruited from participating outpatient clinics in the UK and Jordan. Medication adherence was determined via self-report questionnaires, medication refill data from dispensing records, and via mycophenolic acid concentrations in plasma and DBS samples obtained from children during a clinic visit. RESULTS Through triangulation of results from the different methodological approaches a total of 12 children (36.4%) were deemed to be nonadherent with their prescribed mycophenolate treatment. Logistic regression analysis indicated that nonadherence was significantly associated with the presence of mycophenolate side effects. Poor adherence was positively linked to measures of poor clinical outcomes (hospitalisation and the need for kidney biopsy). CONCLUSIONS Despite the imperative regarding medication adherence to help prevent organ rejection, a significant proportion of children are not fully adherent with their therapy. Side-effects appear to be an important factor leading to nonadherence. Measurement of mycophenolate in DBS samples, coupled with the use of population pharmacokinetics modelling, was a convenient direct approach to assessing adherence in children with kidney transplant and has the potential to be introduced into routine practice.
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Affiliation(s)
- Reham Almardini
- Department of Pediatric Nephrology, King Hussien Medical Center, Amman, Jordan
| | - Esra' O Taybeh
- Department of Applied Pharmaceutical Sciences, School of Pharmacy, Isra University, Amman, Jordan.,Clinical and Practice Research Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Mervat M Alsous
- Department of Pharmacy Practice, School of Pharmacy, Yarmouk University, Irbid, Jordan
| | - Ahmed F Hawwa
- Clinical and Practice Research Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
| | - Karl McKeever
- Department of Paediatric Nephrology, Royal Belfast Hospital for Sick Children, Belfast, UK
| | - Rob Horne
- Centre for Behavioural Medicine, UCL School of Pharmacy, University College London, London, UK
| | - James C McElnay
- Clinical and Practice Research Group, School of Pharmacy, Queen's University Belfast, Belfast, UK
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17
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Population pharmacokinetics and Bayesian estimation of mycophenolic acid concentrations in Chinese adult renal transplant recipients. Acta Pharmacol Sin 2017; 38:1566-1579. [PMID: 28836585 DOI: 10.1038/aps.2017.115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 05/10/2017] [Indexed: 12/19/2022] Open
Abstract
Mycophenolate mofetil (MMF) is an important immunosuppressant used in renal transplantation, and mycophenolic acid (MPA) is the active component released from the ester prodrug MMF. The objective of this study was to investigate the population pharmacokinetics of mycophenolic acid (MPA) following oral administration of MMF in Chinese adult renal transplant recipients and to identify factors that explain MPA pharmacokinetic variability. Pharmacokinetic data for MPA and covariate information were retrospectively collected from 118 patients (79 patients were assigned to the group for building the population pharmacokinetic model, while 39 patients were assigned to the validation group). Population pharmacokinetic data analysis was performed using the NONMEM software. The pharmacokinetics of MPA was best described by a two-compartment model with a first-order absorption rate with no lag time. Body weight and serum creatinine level were positively correlated with apparent clearance (CL/F). The polymorphism in uridine diphosphate glucuronosyltransferase gene, UGT2B7, significantly explained the interindividual variability in the initial volume of distribution (V1/F). The estimated population parameters (and interindividual variability) were CL/F 18.3 L/h (34.2%) and V1/F 27.9 L (21.3%). The interoccasion variability was 13.7%. These population pharmacokinetic data have significant clinical value for the individualization of MMF therapy in Chinese adult renal transplant patients.
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18
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Cai W, Ye C, Sun X, Qin K, Qin Y, Zhao D, Wu F, Hu Y, Li H, Tan L. Limited sampling strategy for predicting area under the concentration-time curve for mycophenolic Acid in Chinese adults receiving mycophenolate mofetil and tacrolimus early after renal transplantation. Ther Drug Monit 2016; 37:304-10. [PMID: 25525761 DOI: 10.1097/ftd.0000000000000165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The objective of the study was to investigate the pharmacokinetics of mycophenolate mofetil (MMF) in Chinese adults early after renal transplantation by an enzyme multiplied immunoassay technique and to establish a limited sampling strategy to predict the area under the concentration-time curve for plasma levels of mycophenolic acid (MPA-AUC). METHODS Fifty-eight recipients who underwent renal transplantation with an organ donated after cardiac death used a triple immunosuppressant strategy of MMF, tacrolimus, and prednisone. On the seventh day posttransplantation, plasma samples were collected at 0 hours (pre-dose) and at 0.5, 1, 1.5, 2, 4, 6, 8, 10, and 12 hours postdose (C0h, C0.5h, C1h, C1.5h, C2h, C4h, C6h, C8h, C10h, and C12h, respectively). Enzyme multiplied immunoassay technique was used to measure mycophenolic acid concentration, and model equations were generated by multiple stepwise regression analysis to determine MPA-AUC0-12h. RESULTS The 3-point equation obtained by multiple linear regression analysis was MPA-AUC = 7.951 + 4.04C6h + 1.893C2h + 4.542C10h (adjusted r = 0.863); the 4-point equation was MPA-AUC = 4.272 + 4.074C6h + 1.896C2h + 4.680C10h + 0.859C0.5h (adjusted r = 0.918). The % mean prediction error, % mean absolute error, and % root mean squared prediction error for the best-fit formula using C6h, C2h, C10h, and C0.5h were -0.2%, 8.7%, and 14.2%, respectively. CONCLUSIONS In Chinese adults receiving MMF and tacrolimus early after renal transplantation, the best equation for predicting MPA-AUC0-12h is 4.272 + 4.074C6h + 1.896C2h + 4.680C10h + 0.859C0.5h.
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Affiliation(s)
- Wene Cai
- *Guangxi Key Laboratory of Transplant Medicine, Institute of Transplant Medicine, Nanning; and †Department of Diagnosis, Administration of Old Officer of Beiji Temple, Beijing, China
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19
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Abd Rahman AN, Tett SE, Staatz CE. How accurate and precise are limited sampling strategies in estimating exposure to mycophenolic acid in people with autoimmune disease? Clin Pharmacokinet 2014; 53:227-245. [PMID: 24327238 DOI: 10.1007/s40262-013-0124-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Mycophenolic acid (MPA) is a potent immunosuppressant agent, which is increasingly being used in the treatment of patients with various autoimmune diseases. Dosing to achieve a specific target MPA area under the concentration-time curve from 0 to 12 h post-dose (AUC12) is likely to lead to better treatment outcomes in patients with autoimmune disease than a standard fixed-dose strategy. This review summarizes the available published data around concentration monitoring strategies for MPA in patients with autoimmune disease and examines the accuracy and precision of methods reported to date using limited concentration-time points to estimate MPA AUC12. A total of 13 studies were identified that assessed the correlation between single time points and MPA AUC12 and/or examined the predictive performance of limited sampling strategies in estimating MPA AUC12. The majority of studies investigated mycophenolate mofetil (MMF) rather than the enteric-coated mycophenolate sodium (EC-MPS) formulation of MPA. Correlations between MPA trough concentrations and MPA AUC12 estimated by full concentration-time profiling ranged from 0.13 to 0.94 across ten studies, with the highest associations (r (2) = 0.90-0.94) observed in lupus nephritis patients. Correlations were generally higher in autoimmune disease patients compared with renal allograft recipients and higher after MMF compared with EC-MPS intake. Four studies investigated use of a limited sampling strategy to predict MPA AUC12 determined by full concentration-time profiling. Three studies used a limited sampling strategy consisting of a maximum combination of three sampling time points with the latest sample drawn 3-6 h after MMF intake, whereas the remaining study tested all combinations of sampling times. MPA AUC12 was best predicted when three samples were taken at pre-dose and at 1 and 3 h post-dose with a mean bias and imprecision of 0.8 and 22.6 % for multiple linear regression analysis and of -5.5 and 23.0 % for maximum a posteriori (MAP) Bayesian analysis. Although mean bias was less when data were analysed using multiple linear regression, MAP Bayesian analysis is preferable because of its flexibility with respect to sample timing. Estimation of MPA AUC12 following EC-MPS administration using a limited sampling strategy with samples drawn within 3 h post-dose resulted in biased and imprecise results, likely due to a longer time to reach a peak MPA concentration (t max) with this formulation and more variable pharmacokinetic profiles. Inclusion of later sampling time points that capture enterohepatic recirculation and t max improved the predictive performance of strategies to predict EC-MPS exposure. Given the considerable pharmacokinetic variability associated with mycophenolate therapy, limited sampling strategies may potentially help in individualizing patient dosing. However, a compromise needs to be made between the predictive performance of the strategy and its clinical feasibility. An opportunity exists to combine research efforts globally to create an open-source database for MPA (AUC, concentrations and outcomes) that can be used and prospectively evaluated for AUC target-controlled dosing of MPA in autoimmune diseases.
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Affiliation(s)
- Azrin N Abd Rahman
- School of Pharmacy, Pharmacy Australia Centre of Excellence, University of Queensland, 20 Cornwall St, Woolloongabba, Brisbane, QLD, 4102, Australia.,School of Pharmacy, International Islamic University of Malaysia, Kuantan, Pahang, Malaysia
| | - Susan E Tett
- School of Pharmacy, Pharmacy Australia Centre of Excellence, University of Queensland, 20 Cornwall St, Woolloongabba, Brisbane, QLD, 4102, Australia
| | - Christine E Staatz
- School of Pharmacy, Pharmacy Australia Centre of Excellence, University of Queensland, 20 Cornwall St, Woolloongabba, Brisbane, QLD, 4102, Australia.
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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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Pharmacokinetic modeling of enterohepatic circulation of mycophenolic acid in renal transplant recipients. Kidney Int 2014; 85:1434-43. [DOI: 10.1038/ki.2013.517] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 10/11/2013] [Accepted: 10/17/2013] [Indexed: 11/09/2022]
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Abd Rahman AN, Tett SE, Staatz CE. Clinical Pharmacokinetics and Pharmacodynamics of Mycophenolate in Patients with Autoimmune Disease. Clin Pharmacokinet 2013; 52:303-31. [DOI: 10.1007/s40262-013-0039-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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23
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Yau WP, Vathsala A, Lou HX, Zhou S, Chan E. Mechanism-Based Enterohepatic Circulation Model of Mycophenolic Acid and Its Glucuronide Metabolite: Assessment of Impact of Cyclosporine Dose in Asian Renal Transplant Patients. J Clin Pharmacol 2013; 49:684-99. [DOI: 10.1177/0091270009332813] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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24
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Zhao W, Fakhoury M, Deschênes G, Roussey G, Brochard K, Niaudet P, Tsimaratos M, André JL, Cloarec S, Cochat P, Bensman A, Azougagh S, Jacqz-Aigrain E. Population Pharmacokinetics and Pharmacogenetics of Mycophenolic Acid Following Administration of Mycophenolate Mofetil in De Novo Pediatric Renal-Transplant Patients. J Clin Pharmacol 2013; 50:1280-91. [DOI: 10.1177/0091270009357429] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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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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Honarbakhsh N, Rouini MR, Lesan-Pezeshki M, Javadi MR, Karimzadeh I, Mohebbi N, Gholami K. Mycophenolic Acid pharmacokinetics early after kidney transplant. EXP CLIN TRANSPLANT 2012; 11:112-7. [PMID: 23176542 DOI: 10.6002/ect.2012.0094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
OBJECTIVES To determine the mycophenolic acid pharmacokinetic profile early after transplant in Iranian kidney graft recipients. MATERIALS AND METHODS A cross-sectional study was performed during 6 months in 31 patients who recently had kidney transplant and received fixed doses of mycophenolate mofetil (2 g/d). The plasma levels of mycophenolic acid were determined by high performance liquid chromatography. RESULTS The mean first mycophenolic acid peak level was 10 ± 5 mg/L. The mean mycophenolic acid area under the curve was 26 ± 19 mgh/L and apparent clearance was 57 ± 55 L/h. The mycophenolic acid area under the curve values of only 8 patients (26%) were within the therapeutic range (30-60 mgh/L). The first, second, and third mycophenolic acid peak levels correlated significantly with mycophenolic acid area under the curve (P < .05). Mycophenolic acid concentration at 10 hours had the highest correlation with mycophenolic acid area under the curve (r=0.962; P < .05). No statistically significant differences were evident in the mean mycophenolic acid area under the curve between men and women. CONCLUSIONS There was a high degree of variation between different patients in mycophenolic acid pharmacokinetics early after kidney transplant.
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Affiliation(s)
- Nazanin Honarbakhsh
- Research Center for Rational Use of Drugs, Tehran University of Medical Sciences, Tehran, Iran
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Staatz CE, Tett SE. Maximum a posteriori Bayesian estimation of mycophenolic Acid area under the concentration-time curve: is this clinically useful for dosage prediction yet? Clin Pharmacokinet 2012; 50:759-72. [PMID: 22087863 DOI: 10.2165/11596380-000000000-00000] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This review seeks to summarize the available data about Bayesian estimation of area under the plasma concentration-time curve (AUC) and dosage prediction for mycophenolic acid (MPA) and evaluate whether sufficient evidence is available for routine use of Bayesian dosage prediction in clinical practice. A literature search identified 14 studies that assessed the predictive performance of maximum a posteriori Bayesian estimation of MPA AUC and one report that retrospectively evaluated how closely dosage recommendations based on Bayesian forecasting achieved targeted MPA exposure. Studies to date have mostly been undertaken in renal transplant recipients, with limited investigation in patients treated with MPA for autoimmune disease or haematopoietic stem cell transplantation. All of these studies have involved use of the mycophenolate mofetil (MMF) formulation of MPA, rather than the enteric-coated mycophenolate sodium (EC-MPS) formulation. Bias associated with estimation of MPA AUC using Bayesian forecasting was generally less than 10%. However some difficulties with imprecision was evident, with values ranging from 4% to 34% (based on estimation involving two or more concentration measurements). Evaluation of whether MPA dosing decisions based on Bayesian forecasting (by the free website service https://pharmaco.chu-limoges.fr) achieved target drug exposure has only been undertaken once. When MMF dosage recommendations were applied by clinicians, a higher proportion (72-80%) of subsequent estimated MPA AUC values were within the 30-60 mg · h/L target range, compared with when dosage recommendations were not followed (only 39-57% within target range). Such findings provide evidence that Bayesian dosage prediction is clinically useful for achieving target MPA AUC. This study, however, was retrospective and focussed only on adult renal transplant recipients. Furthermore, in this study, Bayesian-generated AUC estimations and dosage predictions were not compared with a later full measured AUC but rather with a further AUC estimate based on a second Bayesian analysis. This study also provided some evidence that a useful monitoring schedule for MPA AUC following adult renal transplant would be every 2 weeks during the first month post-transplant, every 1-3 months between months 1 and 12, and each year thereafter. It will be interesting to see further validations in different patient groups using the free website service. In summary, the predictive performance of Bayesian estimation of MPA, comparing estimated with measured AUC values, has been reported in several studies. However, the next step of predicting dosages based on these Bayesian-estimated AUCs, and prospectively determining how closely these predicted dosages give drug exposure matching targeted AUCs, remains largely unaddressed. Further prospective studies are required, particularly in non-renal transplant patients and with the EC-MPS formulation. Other important questions remain to be answered, such as: do Bayesian forecasting methods devised to date use the best population pharmacokinetic models or most accurate algorithms; are the methods simple to use for routine clinical practice; do the algorithms actually improve dosage estimations beyond empirical recommendations in all groups that receive MPA therapy; and, importantly, do the dosage predictions, when followed, improve patient health outcomes?
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Baudouin V, Alberti C, Lapeyraque AL, Bensman A, André JL, Broux F, Cailliez M, Decramer S, Niaudet P, Deschênes G, Jacqz-Aigrain E, Loirat C. Mycophenolate mofetil for steroid-dependent nephrotic syndrome: a phase II Bayesian trial. Pediatr Nephrol 2012; 27:389-96. [PMID: 21947272 DOI: 10.1007/s00467-011-2006-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/30/2011] [Accepted: 08/31/2011] [Indexed: 10/17/2022]
Abstract
Mycophenolate mofetil (MMF) has emerged as a new therapeutic option in steroid-dependent nephrotic syndrome (SDNS). We conducted a phase II Bayesian trial of MMF in children with SDNS. Phase II trials, usually single-arm studies, investigate the effect of new treatments. Standard Fleming's procedure relies on observed results (relapse rate during the trial), whereas Bayesian approach combines observed results with prior information (expected relapse rate according to prior studies and clinical experience). All patients were required to have received prior alkylating-agent treatment. Sixty-seven percent of them had also received levamisole. Patients received MMF (1,200 mg/m(2)/day) and prednisone according to a defined schedule [reduction of alternate-day (e.o.d) dose to 50% of pre-MMF dose at 3 months, 25% at 6 months]. Twenty-four children (median age 6.0 years, 2.8-14.4) entered the study and 23 completed it. Bayesian analysis showed that adding four patients would not change significance of results, allowing stopping inclusions. Four patients relapsed during the first 6 months (estimated probability 17.6%, 95% credibility interval: 5.4-35.0%) and two at months 8 and 11.5. In the 19 patients free of relapse during the first 6 months, median (Q1-Q3) prednisone maintenance dose decreased from 25 (10-44) to 9 (7.5-11.2) mg/m(2) e.o.d (p < 0.001) and cumulative dose from 459 (382-689) to 264 (196-306) mg/m(2)/month (p < 0.001) before and on MMF respectively. Pre-MMF patient characteristics and MMF pharmacokinetics did not differ between patients with or without relapse. MMF reduces relapse rate and steroid dose in children with SDNS and should be proposed before cyclosporine and cyclophosphamide.
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Affiliation(s)
- Véronique Baudouin
- Assistance Publique-Hôpitaux de Paris, Hôpital Robert Debré, Pediatric Nephrology Department, Université Paris 7, 48 Boulevard Sérurier, 75019, Paris, France
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Optimal sampling strategy development methodology using maximum a posteriori Bayesian estimation. Ther Drug Monit 2011; 33:133-46. [PMID: 21383653 DOI: 10.1097/ftd.0b013e31820f40f8] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Maximum a posteriori Bayesian (MAPB) pharmacokinetic parameter estimation is an accurate and flexible method of estimating individual pharmacokinetic parameters using individual blood concentrations and prior information. In the past decade, many studies have developed optimal sampling strategies to estimate pharmacokinetic parameters as accurately as possible using either multiple regression analysis or MAPB estimation. This has been done for many drugs, especially immunosuppressants and anticancer agents. Methods of development for optimal sampling strategies (OSS) are diverse and heterogeneous. This review provides a comprehensive overview of OSS development methodology using MAPB pharmacokinetic parameter estimation, determines the transferability of published OSSs, and compares sampling strategies determined by MAPB estimation and multiple regression analysis. OSS development has the following components: 1) prior distributions; 2) reference value determination; 3) optimal sampling time identification; and 4) validation of the OSS. Published OSSs often lack all data necessary for the OSS to be clinically transferable. MAPB estimation is similar to multiple regression analysis in terms of predictive performance but superior in flexibility.
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Sherwin CMT, Fukuda T, Brunner HI, Goebel J, Vinks AA. The evolution of population pharmacokinetic models to describe the enterohepatic recycling of mycophenolic acid in solid organ transplantation and autoimmune disease. Clin Pharmacokinet 2011; 50:1-24. [PMID: 21142265 DOI: 10.2165/11536640-000000000-00000] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
With the increasing use of mycophenolic acid (MPA) as an immunosuppressant in solid organ transplantation and in treating autoimmune diseases such as systemic lupus erythematosus, the need for strategies to optimize therapy with this agent has become increasingly apparent. This need is largely based on MPA's significant between-subject and between-occasion (within-subject) pharmacokinetic variability. While there is a strong relationship between MPA exposure and effect, the relationship between drug dose, plasma concentration and exposure (area under the concentration-time curve [AUC]) is very complex and remains to be completely defined. Population pharmacokinetic models using various approaches have been proposed over the past 10 years to further evaluate the pharmacokinetic and pharmacodynamic behaviour of MPA. These models have evolved from simple one-compartment linear iterations to complex multi-compartment versions that try to include various factors, which may influence MPA's pharmacokinetic variability, such as enterohepatic recycling and pharmacogenetic polymorphisms. There have been major advances in the understanding of the roles transport mechanisms, metabolizing and other enzymes, drug-drug interactions and pharmacogenetic polymorphisms play in MPA's pharmacokinetic variability. Given these advances, the usefulness of empirical-based models and the limitations of nonlinear mixed-effects modelling in developing mechanism-based models need to be considered and discussed. If the goal is to individualize MPA dosing, it needs to be determined whether factors which may contribute significantly to variability can be utilized in the population pharmacokinetic models. Some pharmacokinetic models developed to date show promise in being able to describe the impact of physiological processes such as enterohepatic recycling. Most studies have historically been based on retrospective data or poorly designed studies which do not take these factors into consideration. Modelling typically has been undertaken using non-controlled therapeutic drug monitoring data, which do not have the information content to support the development of complex mechanistic models. Only a few recent modelling approaches have moved away from empiricism and have included mechanisms considered important, such as enterohepatic recycling. It is recognized that well thought-out sampling schedules allow for better evaluation of the pharmacokinetic data. It is not possible to undertake complex absorption modelling with very few samples being obtained during the absorption phase (which has often been the case). It is important to utilize robust AUC monitoring which is now being propagated in the latest consensus guideline on MPA therapeutic drug monitoring. This review aims to explore the biological factors that contribute to the clinical pharmacokinetics of MPA and how these have been introduced in the development of population pharmacokinetic models. An overview of the processes involved in the enterohepatic recycling of MPA will be provided. This will summarize the components that complicate absorption and recycling to influence MPA exposure such as biotransformation, transport, bile physiology and gut flora. Already published population pharmacokinetic models will be examined, and the evolution of these models away from empirical approaches to more mechanism-based models will be discussed.
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Affiliation(s)
- Catherine M T Sherwin
- Division of Clinical Pharmacology, Cincinnati Childrens Hospital Medical Center, Cincinnati, Ohio 45229-3039, USA
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Developmental pharmacogenetics of immunosuppressants in pediatric organ transplantation. Ther Drug Monit 2011; 32:688-99. [PMID: 21068645 DOI: 10.1097/ftd.0b013e3181f6502d] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cyclosporine, tacrolimus, sirolimus, and mycophenolate mofetil are the primary immunosuppressants used on pediatric organ transplantation. Therapeutic drug monitoring is used in daily practice, because their clinical use is hampered by a narrow therapeutic index and large variability. Tailoring immunosuppressive therapy to the individual patient to optimize efficacy and minimize toxicity is therefore essential. Because research in pharmacogenetics already identified polymorphisms impacting their pharmacokinetic parameters in adults, developmental pharmacogenetics of immunosuppressants holds promises for optimizing dosage regimens and improving clinical outcome in children. In this review, we focus on the impact of age and pharmacogenetics on these immunosuppressants in children undergoing organ transplantation.
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Zeng L, Blair EYL, Nath CE, Shaw PJ, Earl JW, Stephen K, Montgomery K, Coakley JC, Hodson E, Stormon M, McLachlan AJ. Population pharmacokinetics of mycophenolic acid in children and young people undergoing blood or marrow and solid organ transplantation. Br J Clin Pharmacol 2011; 70:567-79. [PMID: 20840448 DOI: 10.1111/j.1365-2125.2010.03734.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIMS To characterize the population pharmacokinetics of mycophenolic acid (MPA) and evaluate dose regimens using a simulation approach and accepted therapeutic drug monitoring targets in children and young people undergoing blood or marrow, kidney and liver transplantation. METHODS MPA concentration-time data were collected using an age specific sampling protocol over 12h. Some patients provided randomly timed but accurately recorded blood samples. Total and unbound MPA were measured by HPLC. NONMEM was employed to analyze MPA pharmacokinetic data. Simulations (n= 1000) were conducted to assess the suitability of the MPA dose regimens to maintain total MPA AUC(0,12h) within the range 30 and 60mg l(-1) h associated with optimal outcome. RESULTS A two-compartment pharmacokinetic model with first-order elimination best described MPA concentration-time data. Population mean estimates of MPA clearance, inter-compartmental clearance, volumes of distribution in the central and peripheral compartments, absorption rate constant and bioavailability were 6.42 l h(-1) , 3.74 l h(-1) , 7.24 l, 16.8l, 0.39h(-1) and 0.48, respectively. Inclusion of bodyweight and concomitant ciclosporin reduced the inter-individual variability in CL from 54.3% to 31.6%. Children with a bodyweight of 10kg receiving standard MPA dose regimens achieve an MPA AUC below the target range suggesting they may be at a greater risk of acute rejection. CONCLUSIONS The population pharmacokinetic model for MPA can be used to explore dosing guidelines for safe and effective immunotherapy in children and young people undergoing transplantation.
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Affiliation(s)
- Lihua Zeng
- Faculty of Pharmacy Department of Paediatrics and Child Health, University of Sydney, Sydney
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Saint-Marcoux F, Guigonis V, Decramer S, Gandia P, Ranchin B, Parant F, Bessenay L, Libert F, Harambat J, Bouchet S, Broux F, Compagnon P, Marquet P. Development of a Bayesian estimator for the therapeutic drug monitoring of mycophenolate mofetil in children with idiopathic nephrotic syndrome. Pharmacol Res 2011; 63:423-31. [PMID: 21272643 DOI: 10.1016/j.phrs.2011.01.009] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 01/13/2011] [Accepted: 01/14/2011] [Indexed: 11/24/2022]
Abstract
The use of mycophenolate mofetil (MMF) in children with idiopathic nephrotic syndrome (INS) is increasing. However, the clinical benefit of its monitoring has been scarcely studied, and little is known about its pharmacokinetics in this context. The objectives of the present study were: (i) to study and model the pharmacokinetics of mycophenolic acid (MPA; the active moiety of MMF) in paediatric patients with INS given MMF, at all stages of the disease; (ii) to develop a Bayesian estimator (MAP-BE) for individual inter-dose area under the concentration-time curve (AUC) prediction in this population, using a limited blood sampling strategy (LSS). Full-pharmacokinetic (PK) profiles of MPA collected in paediatric inpatients with INS already treated with a maintenance immunosuppressive therapy based on MMF (with no calcineurin inhibitors; CNI) were studied. A classical iterative two-stage (ITS) method was applied to model the data and develop MAP-BEs using a one-compartment open model where the absorption is described by a double gamma law allowing the description of a potential enterohepatic recirculation. The performance of the MAP-BE developed for individual exposure assessment was evaluated by the bias and precision of predicted AUCs with respect to measured, trapezoidal AUCs (reference value), and by the proportion of predicted AUCs with absolute error >20%. These PK tools were tested in an independent group of patients. Sixty PK profiles of MPA from children receiving MMF in association to corticosteroids or given alone were included in the study. Forty-five of these PK profiles were used to develop a PK model and a MAP-BE, and 15 for their validation. In the building group, the PK model fitted accurately the PK profiles of MPA: mean residual error of modelled vs. reference AUC was m±SD=-0.015±0.092 (range: -0.153 to 0.204). The MAP-BE which allowed the estimation of MPA AUC on the basis of a 20 min-60 min-180 min LSS was then developed. In the independent group of patients, its mean residual error vs. reference AUCs was m±SD=-0.036±0.145 (range: -0.205 to 0.189). Thus, a PK model and its derived MAP-BE for MMF (without any associated CNI) when given to children with INS have been developed. Clinical trials using these PK tools could test the potential impact of the therapeutic drug monitoring of MMF based on the AUC on the clinical evolution of INS.
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Abstract
Therapeutic drug monitoring (TDM) is central to optimize drug efficacy in children, because the pharmacokinetics and pharmacodynamics of most drugs differ greatly between children and adults. Many factors should be analyzed to implement TDM in the pediatric population, including a validated pharmacological parameter and an analytical method adapted to children as limited sampling volumes and high sensitivity are required. The use of population approaches, new analytical methods such as saliva and dried blood spots, and pharmacodynamic monitoring give attractive options to improve TDM, individualize therapy in order to optimize efficacy and reduce adverse drug reactions.
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Affiliation(s)
- Wei Zhao
- Department of Pediatric Pharmacology and Pharmacogenetics, Clinical Investigation Center, CIC Inserm 9202, French network of Pediatric Investigation Centers, Hôpital Robert Debré, 48 Boulevard Sérurier, 75935 Paris, France
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Raggi M, Siebert S, Abendroth D, Steimer W, Friess H, Thorban S. Neither Mycophenolate Acyl-Glucuronide Levels nor Their Areas Under the Curve Are Responsible for the Gastrointestinal Side Effects in Kidney Transplant Recipients Receiving EC-MPA: A Prospective Trial. Transplant Proc 2010; 42:4049-52. [DOI: 10.1016/j.transproceed.2010.09.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 09/09/2010] [Indexed: 10/18/2022]
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Zhao W, Elie V, Baudouin V, Bensman A, André JL, Brochard K, Broux F, Cailliez M, Loirat C, Jacqz-Aigrain E. Population pharmacokinetics and Bayesian estimator of mycophenolic acid in children with idiopathic nephrotic syndrome. Br J Clin Pharmacol 2010; 69:358-66. [PMID: 20406220 DOI: 10.1111/j.1365-2125.2010.03615.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
AIMS To develop a population pharmacokinetic model for mycophenolic acid (MPA) in children with idiopathic nephrotic syndrome (INS) treated with mycophenolate mofetil (MMF), identify covariates that explain variability and determine the Bayesian estimator of the area under the concentration-time curve over 12 h (AUC(0-12)). METHODS The pharmacokinetic model of MMF was described from 23 patients aged 7.4 +/- 3.9 years (range 2.9-14.9) using nonlinear mixed-effects modelling (NONMEM) software. A two-compartment model with lag-time and first-order absorption and elimination was developed. The final model was validated using visual predictive check. Bayesian estimator was validated using circular permutation method. RESULTS The population pharmacokinetic parameters were apparent oral clearance 9.7 l h(-1), apparent central volume of distribution 22.3 l, apparent peripheral volume of distribution 250 l, inter-compartment clearance 18.8 l h(-1), absorption rate constant 5.16 h(-1), lag time 0.215 h. The covariate analysis identified body weight and serum albumin as individual factors influencing the apparent oral clearance. Accurate Bayesian estimation of AUC(0-12) was obtained using the combination of three MPA concentrations measured just before (T(0)), 1 and 4 h (T(1) and T(4)) after drug intake with a small error of 0.298 microg h(-1) ml(-1) between estimated and reference AUC(0-12). CONCLUSIONS The population pharmacokinetic model of MPA was developed in children with INS. A three-point (T(0), T(1) and T(4)h) Bayesian estimator of AUC(0-12) was developed and might be used to investigate the relation between MPA pharmacokinetic and pharmacodynamics in children with INS and determine if there is any indication to monitor MPA exposure in order to improve patient outcome based on individual AUC-controlled MMF dosing.
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Affiliation(s)
- Wei Zhao
- Department of Paediatric Pharmacology and Pharmacogenetics, Clinical Investigation Centre INSERM, Hôpital Robert Debré, Paris, France
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Urschel S, Altamirano-Diaz LA, West LJ. Immunosuppression armamentarium in 2010: mechanistic and clinical considerations. Pediatr Clin North Am 2010; 57:433-57, table of contents. [PMID: 20371046 DOI: 10.1016/j.pcl.2010.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Effective immunosuppression is the key to successful organ transplantation, with success being defined as minimal rejection risk with concomitant minimal drug toxicities. Despite the general recognition of this fact, a paucity of appropriate clinical trials in children has contributed to lack of standardization of clinical management regimens, resulting in an extensive diversity of favored approaches. Nonetheless, although consensus has not been reached on the ideal approach to immunosuppression in pediatric transplantation, new drug therapies have contributed to a continuing improvement in graft and patient survival. Future clinical research must focus on diminishing the extensive burden of toxicities of these therapeutic agents in children.
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Affiliation(s)
- Simon Urschel
- Cardiac Transplant Research, University of Alberta, Alberta Diabetes Institute, Edmonton, AB T6G 2E1, Canada
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Bruchet NK, Ensom MHH. Limited sampling strategies for mycophenolic acid in solid organ transplantation: a systematic review. Expert Opin Drug Metab Toxicol 2009; 5:1079-97. [PMID: 19689217 DOI: 10.1517/17425250903114182] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Mycophenolic acid (MPA) is the active metabolite of mycophenolate mofetil, a widely used immunosuppressant. Numerous studies have developed limited sampling strategies (LSSs) to predict MPA AUC in solid organ transplant recipients. OBJECTIVES To systematically review and assess quality of literature pertaining to MPA LSSs, evaluate clinical implications and provide suggestions for future research. METHODS Literature searches of MEDLINE (1966 - May 2009) and EMBASE (1980 - May 2009) for English articles in solid organ transplantation, along with manual review of article references were conducted. Included articles were categorized according to criteria adapted from levels of evidence of the US Preventative Services Task Force. RESULTS Of a total of 29 studies identified, 20 were in kidney, 4 in heart, 4 in liver and 1 in lung transplantation and 7 were in pediatrics. A total of 14 studies were deemed to be Level I evidence studies, 3 were Level II-1, 1 was Level II-2 and 11 were Level III. CONCLUSIONS Although various LSSs that are well correlated to MPA AUC while being relatively unbiased and precise to predict MPA AUC have been developed, further research is needed to determine validity of these LSSs in a variety of patient populations and to determine if these LSSs improve patient outcomes.
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Models for the prediction of mycophenolic acid area under the curve using a limited-sampling strategy and an enzyme multiplied immunoassay technique in Chinese patients undergoing liver transplantation. Clin Ther 2009; 30:2387-401. [PMID: 19167597 DOI: 10.1016/j.clinthera.2008.12.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/24/2008] [Indexed: 01/15/2023]
Abstract
BACKGROUND An enzyme multiplied immunoassay technique (EMIT) provides convenient and accurate measurements of mycophenolic acid (MPA) concentrations for determination of immunosuppression during treatment with mycophenolate mofetil (MMF). No abbreviated model for estimating the full 12-hour MPA AUC using an EMIT assay in liver transplant recipients has been described previously. OBJECTIVE This study was conducted to determine the best model for predicting the MPA AUC using the EMIT method and a limited-sampling strategy in Chinese patients undergoing liver transplantation. METHODS The study enrolled consecutive liver transplant patients who were receiving MMF 1 g BID along with tacrolimus. A complete MPA pharmacokinetic profile was obtained for each patient on a single day, 7 to 14 days after transplantation. The EMIT method was used to determine MPA concentrations before dosing and at 0.5, 1, 1.5, 2, 4, 6, 8, 10, and 12 hours after dosing on the sampling day. Multiple linear regression analysis was used to evaluate potential models for estimating the full 12-hour MPA AUC. The accuracy and robustness of the models were evaluated using bootstrap analysis. Prediction error and prediction bias were calculated. Agreement between the estimated MPA AUC(0-12) and the full 12-hour MPA AUC was investigated using Bland-Altman analysis. RESULTS The study enrolled 48 Chinese liver transplant recipients (45 male, 3 female) with a mean (SD) age of 50 (12) years, mean weight of 64 (12) kg, and mean height of 169 (6) cm. Twenty-four models that included blood sampling at 1 through 4 time points were developed (r(2) = 0.015-0.950). Four models with the highest r(2) values were selected; the lack of significant differences from the original dataset on bootstrap analysis indicated acceptable accuracy and robustness. The best model for predicting the MPA AUC(0-12) employed concentrations at 1, 2, 4, and 8 hours; 40 of 48 (83.3%) MPA AUC(0-12) values estimated using this model were within 15% of the full 12-hour MPA AUC. This model had a minimal mean prediction error (mean [SD], 0.27% [1.79%]) and mean absolute prediction error (8.83% [1.24%]). On Bland-Altman analysis, this model also had the best agreement between the estimated MAP AUC(0-12) and the full 12-hour MPA AUC, with a mean error of 9.02 mg . h/L. CONCLUSIONS In this small group of Chinese liver transplant patients receiving MMF and concomitant tacrolimus, models for estimating the MPA AUC(0-12) were developed using the EMIT method and a limited-sampling strategy. The best model for prediction of the full 12-hour MPA AUC was 4.46 + 0.81 . C1 + 1.78 . C(2)+2.51.C(4)+4.94.C8.
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Irtan S, Azougagh S, Monchaud C, Popon M, Baudouin V, Jacqz-Aigrain E. Comparison of high-performance liquid chromatography and enzyme-multiplied immunoassay technique to monitor mycophenolic acid in paediatric renal recipients. Pediatr Nephrol 2008; 23:1859-65. [PMID: 18594872 DOI: 10.1007/s00467-008-0877-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 04/16/2008] [Accepted: 04/18/2008] [Indexed: 11/30/2022]
Abstract
Therapeutic drug monitoring (TDM) of mycophenolate mofetil (MMF) is recommended to guide immunosuppression. High-performance liquid chromatography with ultraviolet (HPLC-UV) or the enzyme-multiplied immunoassay technique (EMIT), used to measure mycophenolic acid (MPA) were compared in an exclusive paediatric renal transplant population. Twenty patients were included as part of the pharmacokinetics study of MMF, and 88 additional samples were drawn for TDM. Agreement between HPLC-UV and EMIT was assessed by the Bland-Altman method. With the two methods, pre-dose concentrations were not normally distributed. After logarithmic transformation, their mean was 0.79 +/- 1.16 microg ml(-1) and their mean difference was 0.34 +/- 0.16 microg ml(-1) [95% confidence interval (95%CI 0.30-0.38 microg ml(-1), with antilogarithmic values of these limits of 1.34-1.46 microg ml(-1)). Area under the curve (AUC)(HPLC) and AUC(EMIT) were normally distributed. Their mean was 52.42 +/- 25.91 mg x h/l and their mean difference was 15.22 +/- 8 mg x h/l (95%CI 11.99-18.45 mg x h/l), the Bland-Altman plot showing a bias proportional to the mean. Our data showed the absence of agreement between the HPLC and EMIT methods, with an average positive bias of 15% with the EMIT. Further studies are required to determine which method is best appropriate for TDM of MMF in children.
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Affiliation(s)
- Sabine Irtan
- Department of Paediatric Pharmacology and Pharmacogenetics, Hôpital Robert Debré, 75019, Paris, France
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Does the Evidence Support the Use of Mycophenolate Mofetil Therapeutic Drug Monitoring in Clinical Practice? A Systematic Review. Transplantation 2008; 85:1675-85. [DOI: 10.1097/tp.0b013e3181744199] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Hao C, Erzheng C, Anwei M, Zhicheng Y, Baiyong S, Xiaxing D, Weixia Z, Chenghong P, Hongwei L. Validation of limited sampling strategy for the estimation of mycophenolic acid exposure in Chinese adult liver transplant recipients. Liver Transpl 2007; 13:1684-93. [PMID: 18044788 DOI: 10.1002/lt.21293] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mycophenolate mofetil (MMF) is indicated as immunosuppressive therapy in liver transplantation. The abbreviated models for the estimation of mycophenolic acid (MPA) area under the concentration-time curve (AUC) have been established by limited sampling strategies (LSSs) in adult liver transplant recipients. In the current study, the performance of the abbreviated models to predict MPA exposure was validated in an independent group of patients. A total of 30 MPA pharmacokinetic profiles from 30 liver transplant recipients receiving MMF in combination with tacrolimus were used to compare 8 models' performance with a full 10 time-point MPA-AUC. Linear regression analysis and Bland-Altman analysis were used to compare the estimated MPA-AUC0-12h from each model against the measured MPA-AUC0-12h. A wide range of agreement was shown when estimated MPA-AUC0-12h was compared with measured MPA-AUC0-12h, and the range of coefficient of determination (r2) was from 0.479 to 0.936. The model based on MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h had the best ability to predict measured MPA-AUC0-12h, with the best coefficient of determination (r2=0.936), the excellent prediction bias (2.18%), the best prediction precision (5.11%), and the best prediction variation (2SD=+/-7.88 mg.h/L). However, the model based on MPA pharmacokinetic sampling time points C1h, C2h, and C4h was more suitable when concerned with clinical convenience, which had shorter sampling interval, an excellent coefficient of determination (r2=0.795), an excellent prediction bias (3.48%), an acceptable prediction precision (14.37%), and a good prediction variation (2SD=+/-13.23 mg.h/L). Measured MPA-AUC0-12h could be best predicted by using MPA pharmacokinetic parameters C1h, C2h, C6h, and C8h. The model based on MPA pharmacokinetic parameters C1h, C2h, and C4h was more feasible in clinical application.
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Affiliation(s)
- Chen Hao
- Center of Organ Transplantation, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China.
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Lobritto SJ, Rosenthal P, Bouw R, Leung M, Snell P, Mamelok RD. Pharmacokinetics of mycophenolate mofetil in stable pediatric liver transplant recipients receiving mycophenolate mofetil and cyclosporine. Liver Transpl 2007; 13:1570-5. [PMID: 17969194 DOI: 10.1002/lt.21274] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
There are few pharmacokinetic data for mycophenolate mofetil (MMF) when used in combination with cyclosporine (CsA) in pediatric liver transplant recipients. The aim of this study was to assess the pharmacokinetics of MMF in stable pediatric liver transplant patients and estimate the dose of MMF required to provide a mycophenolic acid (MPA) exposure similar to that observed in adult liver transplant recipients receiving the recommended dose of MMF (target area under the plasma concentration-time curve from 0 to 12 hours [AUC(0-12)] for MPA of 29 mug.hour/mL in the immediate posttransplantation period and 58 microg x hour/mL after 6 months). A 12-hour pharmacokinetic profile was collected for 8 pediatric patients (mean age 20.9 months) on stable doses of MMF and CsA who had received a liver transplant > or = 6 months prior to entry and who had started on MMF within 2 weeks of transplantation. Mean MMF dosage was 285 mg/m(2) (range, 200-424 mg/m(2)). Of 8 patients, 7 had a MPA AUC(0-12) (range, 11.0-37.2 microg x hour/mL) well below the target. One patient had an AUC(0-12) > or = 58 microg x hour/mL but was considered an outlier and was excluded from analyses. Mean MPA AUC(0-12) and maximum plasma concentration values were 22.7 +/- 10.5 microg x hour/mL and 7.23 +/- 3.27 microg/mL, respectively; values normalized to 600 mg/m(2) (the approved pediatric dose in renal transplantation) were 47.0 +/- 21.8 microg x hour/mL and 14.5 +/- 4.21 microg/mL. In conclusion, assuming that MPA exhibits linear pharmacokinetics, when used in combination with CsA, a MMF dose of 740 mg/m(2) twice daily would be recommended in pediatric liver transplant recipients to achieve MPA exposures similar to those observed in adult liver transplant recipients. This finding should be confirmed by a prospective trial.
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Affiliation(s)
- Steven J Lobritto
- Center for Liver Disease and Transplantation, Columbia University, New York, NY 10032, USA.
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Carlucci F, Anzini M, Rovini M, Cattaneo D, Merlini S, Tabucchi A. Development of a CE method for the determination of mycophenolic acid in human plasma: A comparison with HPLC. Electrophoresis 2007; 28:3908-14. [DOI: 10.1002/elps.200700190] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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45
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Wang CX, Meng FH, Chen LZ, Ren B, Li SX, Fei JG, Qiu J, Deng SX, Li J, Chen SY. Population pharmacokinetics of mycophenolic acid in senile Chinese kidney transplant recipients. Transplant Proc 2007; 39:1392-5. [PMID: 17580146 DOI: 10.1016/j.transproceed.2007.02.082] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2006] [Accepted: 02/05/2007] [Indexed: 11/23/2022]
Abstract
To explore the pharmacokinetic characteristics of mycophenolic acid (MPA) among elderly Chinese kidney transplant recipients, we enrolled 24 patients over 60 years old (65.6 +/- 3.6) as the (Gs) group and 24 patients of 39.6 +/- 14.3 years old as a control group (Ga). Venous blood samples were taken at 0 (predose), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 10, and 12 hours after the morning dose of mycophenolate mofetil at 10 to 12 weeks posttransplant. Plasma MPA concentrations were measured by a validated high-performance liquid chromatography method. Within 6-month posttransplant follow-up, there had not been an acute rejection episode when five elderly and one other adult experienced severe adverse events (SAEs), such as pneumonia and leukocytopenia. MPA area under the curve (AUC) in Gs was significantly lower than that among Ga (P < .05), while there was no significant difference in predose, peak concentrations, or peak times (P > .05). The concentration-time curve of Gs showed a bipeak pattern in five patients (20.8%) during the early stage (2 to 4 hours postdose). AUC in the subgroup of Gs with SAEs (n = 5) was significantly higher than that of elderly subjects without SAEs (n = 19) (P = .042). When Gs were subdivided at a cutting AUC point of 25 mug/mL, the SAE incidence was significantly higher in the subgroup with a higher AUC than than those with the lower AUC (P = .047). Through multiple stepwise regression, we obtained a minimal model to estimate MPA AUC of elderly recipients: AUC = 3.0410 + 9.8588 x C(0) + 0.5963 x C(0.5) + 2.5612 x C(3) (R(2) = .893).
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Affiliation(s)
- C X Wang
- Organ Transplant Center, First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
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Shaw LM, Figurski M, Milone MC, Trofe J, Bloom RD. Therapeutic drug monitoring of mycophenolic acid. Clin J Am Soc Nephrol 2007; 2:1062-72. [PMID: 17702714 DOI: 10.2215/cjn.03861106] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Leslie M Shaw
- Department of Pathology & Laboratory Medicine, University of Pennsylvania Medical Center, Philadelphia, PA 19104, USA.
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van Hest RM, Hesselink DA, Vulto AG, Mathot RAA, van Gelder T. Individualization of mycophenolate mofetil dose in renal transplant recipients. Expert Opin Pharmacother 2007; 7:361-76. [PMID: 16503809 DOI: 10.1517/14656566.7.4.361] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The immunosuppressive agent mycophenolate mofetil has been successfully used over the past 10 years to prevent acute allograft rejection after renal transplantation. It has mainly been administered as a fixed dose of mycophenolate mofetil 1000 mg b.i.d. The pharmacokinetics of mycophenolic acid, the active moiety of the prodrug mycophenolate mofetil, show large between-patient variability, and exposure to mycophenolic acid correlates with the risk for acute rejection. This suggests that already excellent clinical results can be further improved by mycophenolate mofetil dose individualization. This review discusses different arguments in favour of individualization of mycophenolate mofetil dose, as well as strategies for managing mycophenolate mofetil therapy individualization, including pharmacokinetic and pharmacodynamic monitoring and dose individualization based on pharmacogenetic information. It is expected that pharmacokinetic monitoring of mycophenolic acid will offer the most effective and feasible tool for mycophenolate mofetil dose individualization.
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Affiliation(s)
- Reinier M van Hest
- Department of Hospital Pharmacy, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands.
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48
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Staatz CE, Tett SE. Clinical pharmacokinetics and pharmacodynamics of mycophenolate in solid organ transplant recipients. Clin Pharmacokinet 2007; 46:13-58. [PMID: 17201457 DOI: 10.2165/00003088-200746010-00002] [Citation(s) in RCA: 427] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This review aims to provide an extensive overview of the literature on the clinical pharmacokinetics of mycophenolate in solid organ transplantation and a briefer summary of current pharmacodynamic information. Strategies are suggested for further optimisation of mycophenolate therapy and areas where additional research is warranted are highlighted. Mycophenolate has gained widespread acceptance as the antimetabolite immunosuppressant of choice in organ transplant regimens. Mycophenolic acid (MPA) is the active drug moiety. Currently, two mycophenolate compounds are available, mycophenolate mofetil and enteric-coated (EC) mycophenolate sodium. MPA is a potent, selective and reversible inhibitor of inosine monophosphate dehydrogenase (IMPDH), leading to eventual arrest of T- and B-lymphocyte proliferation. Mycophenolate mofetil and EC-mycophenolate sodium are essentially completely hydrolysed to MPA by esterases in the gut wall, blood, liver and tissue. Oral bioavailability of MPA, subsequent to mycophenolate mofetil administration, ranges from 80.7% to 94%. EC-mycophenolate sodium has an absolute bioavailability of MPA of approximately 72%. MPA binds 97-99% to serum albumin in patients with normal renal and liver function. It is metabolised in the liver, gastrointestinal tract and kidney by uridine diphosphate gluconosyltransferases (UGTs). 7-O-MPA-glucuronide (MPAG) is the major metabolite of MPA. MPAG is usually present in the plasma at 20- to 100-fold higher concentrations than MPA, but it is not pharmacologically active. At least three minor metabolites are also formed, of which an acyl-glucuronide has pharmacological potency comparable to MPA. MPAG is excreted into the urine via active tubular secretion and into the bile by multi-drug resistance protein 2 (MRP-2). MPAG is de-conjugated back to MPA by gut bacteria and then reabsorbed in the colon. Mycophenolate mofetil and EC-mycophenolate sodium display linear pharmacokinetics. Following mycophenolate mofetil administration, MPA maximum concentration usually occurs in 1-2 hours. EC-mycophenolate sodium exhibits a median lag time in absorption of MPA from 0.25 to 1.25 hours. A secondary peak in the concentration-time profile of MPA, due to enterohepatic recirculation, often appears 6-12 hours after dosing. This contributes approximately 40% to the area under the plasma concentration-time curve (AUC). The mean elimination half-life of MPA ranges from 9 to 17 hours. MPA displays large between- and within-subject pharmacokinetic variability. Dose-normalised MPA AUC can vary more than 10-fold. Total MPA concentrations should be interpreted with caution in patients with severe renal impairment, liver disease and hypoalbuminaemia. In such individuals, MPA and MPAG plasma protein binding may be altered, changing the fraction of free MPA available. Apparent oral clearance (CL/F) of total MPA appears to increase in proportion to the increased free fraction, with a reduction in total MPA AUC. However, there may be little change in the MPA free concentration. Ciclosporin inhibits biliary excretion of MPAG by MRP-2, reducing enterohepatic recirculation of MPA. Exposure to MPA when mycophenolate mofetil is given in combination with ciclosporin is approximately 30-40% lower than when given alone or with tacrolimus or sirolimus. High dosages of corticosteroids may induce expression of UGT, reducing exposure to MPA. Other co-medications can interfere with the absorption, enterohepatic recycling and metabolism of mycophenolate. Most pharmacokinetic investigations of MPA have involved mycophenolate mofetil rather than EC-mycophenolate sodium therapy. In population pharmacokinetic studies, MPA CL/F in adults ranges from 14.1 to 34.9 L/h (ciclosporin co-therapy) and from 11.9 to 25.4 L/h (tacrolimus co-therapy). Patient bodyweight, serum albumin concentration and immunosuppressant co-therapy have a significant influence on CL/F. The majority of pharmacodynamic data on MPA have been obtained in patients receiving mycophenolate mofetil therapy in the first year after kidney transplantation. Low MPA AUC is associated with increased incidence of biopsy-proven acute rejection. Gastrointestinal adverse events may be dose related. Leukopenia and anaemia have been associated with high MPA AUC, trough concentration and metabolite concentrations in some, but not all, studies. High free MPA exposure has been identified as a risk factor for leukopenia in some investigations. Targeting a total MPA AUC from 0 to 12 hours (AUC12) of 30-60 mg.hr/L is likely to minimise the risk of acute rejection and may reduce toxicity. IMPDH monitoring is in the early experimental stage. Individualisation of mycophenolate therapy should lead to improved patient outcomes. MPA AUC12 appears to be the most useful exposure measure for such individualisation. Limited sampling strategies and Bayesian forecasting are practical means of estimating MPA AUC12 without full concentration-time profiling. Target concentration intervention may be particularly useful in the first few months post-transplant and prior to major changes in anti-rejection therapy. In patients with impaired renal or hepatic function or hypoalbuminaemia, free drug measurement could be valuable in further interpretation of MPA exposure.
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Affiliation(s)
- Christine E Staatz
- School of Pharmacy, University of Queensland, Brisbane, Queensland, Australia.
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van Hest RM, van Gelder T, Bouw R, Goggin T, Gordon R, Mamelok RD, Mathot RA. Time-dependent clearance of mycophenolic acid in renal transplant recipients. Br J Clin Pharmacol 2007; 63:741-52. [PMID: 17214827 PMCID: PMC2000600 DOI: 10.1111/j.1365-2125.2006.02841.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIMS Pharmacokinetic studies of the immunosuppressive compound mycophenolic acid (MPA) have shown a structural decrease in clearance (CL) over time after renal transplantation. The aim of this study was to characterize the time-dependent CL of MPA by means of a population pharmacokinetic meta-analysis, and to test whether it can be described by covariate effects. METHODS One thousand eight hundred and ninety-four MPA concentration-time profiles from 468 renal transplant patients (range 1-9 profiles per patient) were analyzed retrospectively by nonlinear mixed effect modelling. Sampling occasions ranged from day 1-10 years after transplantation. RESULTS The pharmacokinetics of MPA were described by a two-compartment model with time-lagged first order absorption, and a first-order term for time-dependent CL. The model predicted the mean CL to decrease from 35 l h(-1) (CV = 44%) in the first week after transplantation to 17 l h(-1) (CV = 38%) after 6 months. In a covariate model without a term for time-dependent CL, changes during the first 6 months after transplantation in creatinine clearance from 19 to 71 ml min(-1), in albumin concentration from 35 to 40 g l(-1), in haemoglobin from 9.7 to 12 g dl(-1) and in cyclosporin predose concentration from 225 to 100 ng ml(-1) corresponded with a decrease of CL from 32 to 19 l h(-1). Creatinine clearance, albumin concentration, haemoglobin and cyclosporin predose concentration explained, respectively, 19%, 12%, 4% and 3% of the within-patient variability in MPA CL. CONCLUSIONS By monitoring creatinine clearance, albumin concentration, haemoglobin and cyclosporin predose concentration, changes in MPA exposure over time can be predicted. Such information can be used to optimize therapy with mycophenolate mofetil.
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Affiliation(s)
- Reinier M van Hest
- Department of Hospital Pharmacy, Erasmus Medical Center, Rotterdam, The Netherlands.
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Ting LSL, Villeneuve E, Ensom MHH. Beyond cyclosporine: a systematic review of limited sampling strategies for other immunosuppressants. Ther Drug Monit 2006; 28:419-30. [PMID: 16778729 DOI: 10.1097/01.ftd.0000211810.19935.44] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Therapeutic drug monitoring has gained much attention in the management of immunosuppressive therapy. Area under the plasma drug concentration-time curve (AUC) is the pharmacokinetic (PK) parameter most commonly used to assess total exposure to a drug. However, estimation of AUC requires multiple blood samples throughout the dosing period, which is often inconvenient and expensive. Limited sampling strategies (LSSs) are therefore developed to estimate AUC and other PK parameters accurately and precisely while minimizing the number of blood samples needed. This greatly reduces costs, labor and inconvenience for both patients and clinical staff. In the therapeutic management of solid organ transplantation, LSSs for cyclosporine are commonplace and have been extensively reviewed. Thus, this systematic review paper focuses on other immunosuppressive agents and categorizes the 24 pertinent citations according to the U.S. Preventive Services Task Force rating scale. Thirteen articles (3 level I, 1 level II-1, 2 level II-2, and 7 level III) involved LSSs for mycophenolate, 7 citations (1 level I and 6 level III) for tacrolimus (TAC), and 3 citations (all level III) for other drugs (sirolimus) or multiple drugs. The 2 main approaches to establishing LSSs, multiple regression and Bayesian analyses, are also reviewed. Important elements to consider for future LSS studies, including proper validation of LSSs, convenient sampling times, and application of LSSs to the appropriate patient population and drug formulation are discussed. Limited sampling strategies are a useful tool to help clinicians make decisions on drug therapy. However, patients' pathophysiology, environmental and genetic factors, and pharmacologic response to therapy, in conjunction with PK profiling tools such as LSSs, should be considered collectively for optimal therapy management.
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Affiliation(s)
- Lillian S L Ting
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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