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Aims: We propose using glomerular filtration rate (GFR) as the physiological basis for distinguishing components of renal clearance. Methods: Gentamicin, amikacin and vancomycin are thought to be predominantly excreted by the kidneys. A mixed‐effects joint model of the pharmacokinetics of these drugs was developed, with a wide dispersion of weight, age and serum creatinine. A dataset created from 18 sources resulted in 27,338 drug concentrations from 9,901 patients. Body size and composition, maturation and renal function were used to describe differences in drug clearance and volume of distribution. Results: This study demonstrates that GFR is a predictor of two distinct components of renal elimination clearance: (1) GFR clearance associated with normal GFR and (2) non‐GFR clearance not associated with normal GFR. All three drugs had GFR clearance estimated as a drug‐specific percentage of normal GFR (gentamicin 39%, amikacin 90% and vancomycin 57%). The total clearance (sum of GFR and non‐GFR clearance), standardized to 70 kg total body mass, 176 cm, male, renal function 1, was 5.58 L/h (95% confidence interval [CI] 5.50‐5.69) (gentamicin), 7.77 L/h (95% CI 7.26‐8.19) (amikacin) and 4.70 L/h (95% CI 4.61‐4.80) (vancomycin). Conclusions: GFR provides a physiological basis for renal drug elimination. It has been used to distinguish two elimination components. This physiological approach has been applied to describe clearance and volume of distribution from premature neonates to elderly adults with a wide dispersion of size, body composition and renal function. Dose individualization has been implemented using target concentration intervention. [ABSTRACT FROM AUTHOR]

Aims: Azathioprine (AZA) and 6‐mercaptopurine are prescribed in acute lymphoblastic leukaemia (ALL) and inflammatory bowel diseases (IBD). Metabolism to active 6‐thioguanine (6TGN) and 6‐methylmercaptopurine nucleotides (6MMPN) is variable but therapeutic drug monitoring (TDM) remains debatable. This study reports on factors impacting on red blood cell (RBC) metabolites concentrations in children to facilitate TDM interpretation. Methods: The first paediatric TDM samples received during year 2021 were analysed, whatever indication and thiopurine drug. Target concentration ranges were 200–500, <6000 pmol/8 × 108 RBC for 6TGN and 6MMPN. Results: Children (n = 492) had IBD (64.8%), ALL (22.6%) or another autoimmune disease (12.6%): mean ages at TDM were 7.5 in ALL and 13.7 years in IBD (P <.0001). ALL received 6‐mercaptopurine (mean dose 1.7 mg/kg/d with methotrexate), IBD received AZA (1.9 mg/kg/d with anti‐inflammatory drugs and/or monoclonal antibodies). Median 6TGN and 6MMPN concentrations were 213.7 [interquartile range: 142.5; 309.6] and 1144.6 [419.4; 3574.3] pmol/8 × 108 RBC, 38.8% of patients were in the recommended therapeutic range for both compounds. Aminotransferases and blood tests were abnormal in 57/260 patients: 8.1% patients had high alanine aminotransaminase, 3.4% of patients had abnormal blood count. Factors associated with increased 6TGN were age at TDM and thiopurine methyltransferase genotype in ALL and AZA dose in IBD. The impact of associated treatment in IBD patients was also significant. Conclusion: TDM allowed identification of children who do not reach target levels or remain over treated. Including TDM in follow‐up may help physicians to adjust dosage with the aim of reducing adverse effects and improve treatment outcome. [ABSTRACT FROM AUTHOR]

Introduction: Mycophenolic acid (MPA), the active metabolite of mycophenolate mofetil (MMF), is widely used in the treatment of systemic lupus erythematosus (SLE). It has been shown that its therapeutic drug monitoring based on the area under the curve (AUC) improves treatment efficacy. MPA exhibits a complex bimodal absorption, and a double gamma distribution model has been already proposed in the past to accurately describe this phenomenon. These previous population pharmacokinetics models (POPPK) have been developed using iterative two stage Bayesian (IT2B) or non-parametric adaptive grid (NPAG) methods. However, non-linear mixed effect (NLME) approaches based on stochastic approximation expectation–maximization (SAEM) algorithms have never been published so far for this particular model. The objectives of this study were (i) to implement the double absorption gamma model in Monolix, (ii) to compare different absorption models to describe the pharmacokinetics of MMF, and (iii) to develop a limited sampling strategy (LSS) to estimate AUC in pediatric SLE patients. Material and methods: A data splitting of full pharmacokinetic profiles sampled in 67 children extracted either from the expert system ISBA (n = 34) or the hospital Saint Louis (n = 33) was performed into train (75%) and test (25%) sets. A POPPK was developed for MPA in the train set using a NLME and the SAEM algorithm and different absorption models were implemented and compared (first order, transit, or simple and double gamma). The best limited sampling strategy was then determined in the test set using a maximum-a-posteriori Bayesian method to estimate individual PK parameters and AUC based on three blood samples compared to the reference AUC calculated using the trapezoidal rule applied on all samples and performances were assessed in the test set. Results: Mean patient age and dose was 13 years old (5–18) and 18.1 mg/kg (7.9–47.6), respectively. MPA concentrations (764) from 107 occasions were included in the analysis. A double gamma absorption with a first-order elimination from the central compartment best fitted the data. The optimal LSS with samples at 30 min, 2 h, and 3 h post-dose exhibited good performances in the test set (mean bias − 0.32% and RMSE 21.0%). Conclusion: The POPPK developed in this study adequately estimated the MPA AUC in pediatric patients with SLE based on three samples. The double absorption gamma model developed with the SAEM algorithm showed very accurate fit and reduced computation time. [ABSTRACT FROM AUTHOR]

The safety and efficacy of pharmacotherapy in children, particularly preterms, neonates and infants, is limited by a paucity of good‐quality data from prospective clinical drug trials. A specific challenge is the establishment of valid biomarkers. OMICs technologies may support these efforts by complementary information about targeted and nontargeted molecules through systematic characterization and quantitation of biological samples. OMICs technologies comprise at least genomics, epigenomics, transcriptomics, proteomics, metabolomics and microbiomics in addition to the patient's phenotype. OMICs technologies are in part hypothesis‐generating, allowing an in depth understanding of disease pathophysiology and pharmacological mechanisms. Application of OMICs technologies in paediatrics faces major challenges before routine adoption. First, developmental processes need to be considered, including a subdivision into specific age groups as developmental changes clearly impact OMICs data. Second, compared to the adult population, the number of patients is limited as are the type and amount of necessary biomaterial, especially in neonates and preterms. Thus, advanced trial designs and biostatistical methods, noninvasive biomarkers, innovative biobanking concepts including data and samples from healthy children, as well as analytical approaches (eg liquid biopsies) should be addressed to overcome these obstacles. The ultimate goal is to link OMICs technologies with innovative analysis tools, such as artificial intelligence at an early stage. The use of OMICs data based on a feasible approach will contribute to the identification complex phenotypes and subpopulations of patients to improve the development of medicines for children with potential economic advantages. [ABSTRACT FROM AUTHOR]

Thiopurine drugs azathioprine (AZA) and 6-mercaptopurine (6-MP) are used extensively in pediatric and adult patients with inflammatory and neoplastic diseases. They are metabolized to 6-thioguanine nucleotides (6-TGN) or to 6-methyl-mercaptopurine nucleotides (6-MMPN). The balance between 6-TGN and 6-MMPN is highly variable and monitoring is recommended, but its benefit in outcome gives rise to conflicting results, potentially increased by differences in quantifying 6-MP metabolism. Our aim was to report (1) the HPLC-UV procedure used in our laboratory to quantify red blood cells (RBCs) with 6-TGN and 6-MMPN (as its derivate: 6-MMP(d)) in patients treated with thiopurines and (2) additional tests, sometimes confirmatory, to improve method standardization. The comparison of two methods to count RBCs shows that metabolite concentrations were slightly lower in the washed and resuspended RBCs than in whole blood. Perchloric acid (0.7 M), dithiothreitol (DTT, final 0.013 M sample concentration) and 60 min hydrolysis were selected for acid hydrolysis. (3) Monitoring data from 83 patients receiving AZA or 6-MP showed that at steady state, only 53/183 (29%) had 6-TGN and 6-MMPN in the recommended therapeutic range. Our method is discussed in light of the technical conditions and sample stability data from 17 publications identified since the first analytical report in 1987. Monitoring data demonstrate, if required, that inter-patient variability in 6-TGN and 6-MMPN concentrations is high in samples from treated patients. [ABSTRACT FROM AUTHOR]

Introduction: Vancomycin is one of the antibiotics most used in neonates. Continuous infusion has many advantages over intermittent infusions, but no consensus has been achieved regarding the optimal initial dose. The objectives of this study were: to develop a Machine learning (ML) algorithm based on pharmacokinetic profiles obtained by Monte Carlo simulations using a population pharmacokinetic model (POPPK) from the literature, in order to derive the best vancomycin initial dose in preterm and term neonates, and to compare ML performances with those of an literature equation (LE) derived from a POPPK previously published. Materials and methods: The parameters of a previously published POPPK model of vancomycin in children and neonates were used in the mrgsolve R package to simulate 1900 PK profiles. ML algorithms were developed from these simulations using Xgboost, GLMNET and MARS in parallel, benchmarked and used to calculate the ML first dose. Performances were evaluated in a second simulation set and in an external set of 82 real patients and compared to those of a LE. Results: The Xgboost algorithm yielded numerically best performances and target attainment rates: 46.9% in the second simulation set of 400–600 AUC/MIC ratio vs. 41.4% for the LE model (p = 0.0018); and 35.3% vs. 28% in real patients (p = 0.401), respectively). The Xgboost model resulted in less AUC/MIC > 600, thus decreasing the risk of nephrotoxicity. Conclusion: The Xgboost algorithm developed to estimate the initial dose of vancomycin in term or preterm infants has better performances than a previous validated LE and should be evaluated prospectively. [ABSTRACT FROM AUTHOR]

Background and Objective: Vancomycin is frequently used to treat Gram-positive bacterial infections in neonates. However, there is still no consensus on the optimal initial dosing regimen. This study aimed to assess the performance of pharmacokinetic model-based virtual trials to predict the dose–exposure relationship of vancomycin in neonates. Methods: The PubMed database was searched for clinical trials of vancomycin in neonates that reported the percentage of target attainment. Monte Carlo simulations were performed using nonlinear mixed-effect modeling to predict the dose–exposure relationship, and the differences in outcomes between virtual trials and real-world data in clinical studies were calculated. Results: A total of 11 studies with 14 dosing groups were identified from the literature to evaluate dose–exposure relationships. For the ten dosing groups where the surrogate marker for exposure was the trough concentration, the mean ± standard deviation (SD) for the target attainment between original studies and virtual trials was 3.0 ± 7.3%. Deviations between − 10 and 10% accounted for 80% of the included dosing groups. For the other four dosing groups where the surrogate marker for exposure was concentration during continuous infusion, all deviations were between − 10 and 10%, and the mean ± SD value was 2.9 ± 4.5%. Conclusion: The pharmacokinetic model-based virtual trials of vancomycin exhibited good predictive performance for dose–exposure relationships in neonates. These results might be used to assist the optimization of dosing regimens in neonatal practice, avoiding the need for trial and error. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: Nowadays, real-world data can be used to improve currently available dosing guidelines and to support regulatory approval of drugs for use in neonates by overcoming practical and ethical hurdles. This proof-of-concept study aimed to assess the population pharmacokinetics of azlocillin in neonates using real-world data, to make subsequent dose recommendations and to test these in neonates with early-onset sepsis (EOS).Methods: This prospective, open-label, investigator-initiated study of azlocillin in neonates with EOS was conducted using an adaptive two-step design. First, a maturational pharmacokinetic-pharmacodynamic model of azlocillin was developed, using an empirical dosing regimen combined with opportunistic samples resulting from waste material. Second, a Phase II clinical trial (ClinicalTrials.gov: NCT03932123) of this newly developed model-based dosing regimen of azlocillin was conducted to assure optimized target attainment [free drug concentration above MIC during 70% of the dosing interval ('70% fT>MIC')] and to investigate the tolerance and safety in neonates.Results: A one-compartment model with first-order elimination, using 167 azlocillin concentrations from 95 neonates (31.7-41.6 weeks postmenstrual age), incorporating current weight and renal maturation, fitted the data best. For the second step, 45 neonates (30.3-41.3 weeks postmenstrual age) were subsequently included to investigate target attainment, tolerance and safety of the pharmacokinetic-pharmacodynamic model-based dose regimen (100 mg/kg q8h). Forty-three (95.6%) neonates reached their pharmacokinetic target and only two neonates experienced adverse events (feeding intolerance and abnormal liver function), possibly related to azlocillin.Conclusions: Target attainment, tolerance and safety of azlocillin was shown in neonates with EOS using a pharmacokinetic-pharmacodynamic model developed with real-world data. [ABSTRACT FROM AUTHOR]

Aims: The aim of the study was to evaluate the suitability of the current caffeine dosing regimen for the Chinese population using modelling and simulation approach. Methods: Pharmacokinetic samples were collected from 99 Chinese newborns with premature apnoea. The median (range) of gestational age and postmenstrual age were 28.3 (25.0–33.4) weeks and 31.1 (26.4–38.0) weeks, respectively. Newborns were receiving caffeine citrate at a loading dose of 20 mg/kg/d and a maintenance dose of 5–10 mg/kg/d. Caffeine concentrations and CYP1A2 polymorphisms were investigated. Population pharmacokinetic modelling of caffeine in Chinese preterm newborn on a population‐wide scale was conducted using NONMEM. Results: A 1‐compartment model with first‐order elimination was used to describe population pharmacokinetic. With current weight implemented using 0.75 allometric scaling, clearance (CL) was positively related to current weight and postmenstrual age, but a negative relationship was observed with serum creatinine concentration. Eight genotypes of CYP1A2 were tested and none of them had a significant impact on caffeine pharmacokinetic parameters. Interindividual variability of CL and volume of distribution was 7.70 and 65.9%. The median (range) of 95% confidence intervals of CL were 0.0128 (0.0128–0.0131) L/h/kg. Monte Carlo simulation demonstrated that 80% (loading dose) and 98% (maintenance dose) of premature infants treated with a labelled dosing regimen attained the concentration target range of 5–20 mg/L. Conclusion: A population PK model of caffeine was developed in Chinese newborns. Body weight‐implemented allometric scaling, postmenstrual age and serum creatinine concentration markedly affected caffeine clearance. The labelled dosing regimen is suitable for Chinese premature infants. [ABSTRACT FROM AUTHOR]

What is known and objectives: Thiopurines are cornerstone drugs in the treatment of acute lymphoblastic leukaemia (ALL), but their use can be complicated by the incidence of life‐threatening leucopenia. Case description: We describe a case of a 6‐year‐old Chinese boy with B‐ALL receiving extremely low dose of 6‐mercaptopurine (only 4% of recommended dose) during the ALL maintenance therapy phase. What is new and conclusion: Complex pharmacogenetic tests and TDM should be recommended in children with complicated ALL to highlight the large individual variability in the responses to 6‐MP exposure and the associated adverse effects. [ABSTRACT FROM AUTHOR]

Purpose: To assess ceftriaxone population pharmacokinetics in a large pediatric population and describe the proper dose for establishing an optimized antibiotic regimen. Methods: From pediatric patients using ceftriaxone, blood samples were obtained and the concentration was measured using high-performance liquid chromatography ultraviolet detection. The NONMEM software program was used for population pharmacokinetic analysis, for which data from 99 pediatric patients (2 to 12 years old) was collected and 175 blood concentrations were obtained. Results: The best fit with the data was shown by the one-compartment model with first-order elimination. According to covariate analysis, weight had a significant impact on the clearance of ceftriaxone. Using Monte Carlo simulation, in a pediatric population with community-acquired pneumonia, a dose regimen of 100 mg/kg every 24 h produced satisfactory target attainment rates while remaining within the required minimum inhibitory concentration (2 mg/L). Conclusion: Population pharmacokinetics of ceftriaxone was evaluated in children and an optimum dosing regimen was constructed on the basis of the pharmacokinetics-pharmacodynamics model-based approach. [ABSTRACT FROM AUTHOR]

Aims: Chinese children are more susceptible to the development of thiopurine‐induced leukopenia compared with Caucasian populations. The aim of our study was to establish a 6‐mercaptopurine (6‐MP) dose–concentration–response relationship through exploration of pharmacogenetic factors involved in the thiopurine‐induced toxicities in Chinese paediatric patients afflicted by acute lymphoblastic leukaemia (ALL). Methods: Blood samples were obtained from ALL children treated with 6‐MP. We determined the metabolite steady‐state concentrations of 6‐MP in red blood cells (RBCs) by using high‐performance liquid chromatography. Pharmacogenetic analysis was carried out on patients' genomic DNA using the MassArray genotyping platform. Results: Sixty children afflicted by ALL who received 6‐MP treatment were enrolled in this study. The median concentration of 6‐thioguanine in patients afflicted by leukopenia was 235.83 pmol/8 × 108 RBCs, which was significantly higher than for patients unafflicted by leukopenia (178.90 pmol/8 × 108 RBCs; P = 0.029). We determined the population special target 6‐thioguanine threshold to have equalled 197.50 pmol/8 × 108 RBCs to predict leukopenia risk in Chinese paediatric patients afflicted by ALL. Among 36 candidate single nucleotide polymorphisms, our results indicated that NUDT15 (rs116855232) and IMPDH1 (rs2278293) were correlated with a 5.50‐fold and 5.80‐fold higher risk of leukopenia, respectively. MTHFR rs1801133 variants were found to have had a 4.46‐fold significantly higher risk of hepatotoxicity vs wild‐type genotype. Conclusion: Our findings support the idea that predetermination of genotypes and monitoring of thiopurine metabolism for Chinese paediatric patients afflicted by ALL is necessary to effectively predict the efficacy of treatments and to minimize the adverse effects of 6‐MP maintenance therapy. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the population pharmacokinetics of cefoperazone in children and establish an evidence-based dosing regimen using a developmental pharmacokinetic-pharmacodynamic approach in order to optimize cefoperazone treatment.Methods: A model-based, open-label, opportunistic-sampling pharmacokinetic study was conducted in China. Blood samples from 99 cefoperazone-treated children were collected and quantified by HPLC/MS. NONMEM software was used for population pharmacokinetic-pharmacodynamic analysis. This study was registered at ClinicalTrials.gov (NCT03113344).Results: A two-compartment model with first-order elimination agreed well with the experimental data. Covariate analysis showed that current body weight had a significant effect on the pharmacokinetics of cefoperazone. Monte Carlo simulation showed that for bacteria for which cefoperazone has an MIC of 0.5 mg/L, 78.1% of hypothetical children treated with '40 mg/kg/day, q8h, IV drip 3 h' would reach the pharmacodynamic target. For bacteria for which cefoperazone has an MIC of 8 mg/L, 88.4% of hypothetical children treated with 80 mg/kg/day (continuous infusion) would reach the treatment goal. A 160 mg/kg/day (continuous infusion) regimen can cover bacteria for which cefoperazone has an MIC of 16 mg/L. Nevertheless, even if using the maximum reported dose of 160 mg/kg/day (continuous infusion), the ratio of hypothetical children reaching the treatment target was only 9.9% for bacteria for which cefoperazone has an MIC of 32 mg/L.Conclusions: For cefoperazone, population pharmacokinetics were evaluated in children and an appropriate dosing regimen was developed based on developmental pharmacokinetics-pharmacodynamics. The dose indicated in the instructions (20-160 mg/kg/day) can basically cover the clinically common bacteria for which cefoperazone has an MIC of ≤16 mg/L. However, for bacteria for which the MIC is >16 mg/L, cefoperazone is not a preferred choice. [ABSTRACT FROM AUTHOR]

Background: Vancomycin has been used in clinical practice for over 50 years; however, validated, pharmacokinetic (PK) data relating clinical outcomes to different dosing regimens in neonates are lacking. Coagulase negative staphylococci (CoNS) are the most commonly isolated organisms in neonatal, late-onset sepsis (LOS). Optimised use to maximise efficacy while minimising toxicity and resistance selection is imperative to ensure vancomycin's continued efficacy.Methods: NeoVanc is a European, open-label, Phase IIb, randomised, controlled, non-inferiority trial comparing an optimised vancomycin regimen to a standard vancomycin regimen when treating LOS known/suspected to be caused by Gram-positive organisms (excluding Staphylococcus aureus) in infants aged ≤ 90 days. Three hundred infants will be recruited and randomised in a 1:1 ratio. Infants can be recruited if they have culture confirmed (a positive culture from a normally sterile site and at least one clinical/laboratory criterion) or clinical sepsis (presence of any ≥ 3 clinical/laboratory criteria) in the 24 h before randomisation. The optimised regimen consists of a vancomycin loading dose (25 mg/kg) followed by 5 ± 1 days of 15 mg/kg q12h or q8h, dependent on postmenstrual age (PMA). The standard regimen is a 10 ± 2 day vancomycin course at 15 mg/kg q24h, q12h or q8h, dependent on PMA. The primary endpoint is a successful outcome at the test of cure visit (10 ± 1 days after the end of vancomycin therapy). A successful outcome consists of the patient being alive, having successfully completed study vancomycin therapy and having not had a clinical/microbiological relapse/new infection requiring treatment with vancomycin or other anti-staphylococcal antibiotic for > 24 h. Secondary endpoints include clinical/microbiological relapse/new infection at the short-term follow-up visit (30 ± 5 days after the initiation of vancomycin), evaluation of safety (renal/hearing), vancomycin PK and assessment of a host biomarker panel over the course of vancomycin therapy.Discussion: Based on previous pre-clinical data and a large meta-analysis of neonatal, PK/pharmacodynamic data, NeoVanc was set up to provide evidence on whether a loading dose followed by a short vancomycin course is non-inferior, regarding efficacy, when compared to a standard, longer course. If non-inferiority is demonstrated, this would support adoption of the optimised regimen as a way of safely reducing vancomycin exposure when treating neonatal, Gram-positive LOS.Trial Registration: ClinicalTrials.gov, NCT02790996. Registered on 7 April 2016. EudraCT, 2015-000203-89. Entered on 18 July 2016. [ABSTRACT FROM AUTHOR]

Background: Clinical trials are conducted during pregnancy to evaluate benefits and risks of medicines for mother and child. The safety of maternal treatments is a key issue for healthcare professionals and parents.Objective: To analyse offspring data reported in clinical trials in pregnant women with diabetes, HIV infection or hypertension (three of the most common diseases in women of childbearing potential) and either treated prior to pregnancy for these chronic diseases or diagnosed and treated during pregnancy.Methods: PubMed and Embase (1 January 1997 to 31 December 2017) were searched for drug trials in pregnant women with diabetes, HIV infection or hypertension. Titles and abstracts were screened, followed by a full-text review of eligible articles. Inclusion criteria were interventional clinical trials in pregnant women treated with medication and full text in English. Trial characteristics, maternal and offspring data were extracted. Data were summarised by disease and study. Twelve key items were considered for the offspring.Results: Overall, 196 articles reporting 132 clinical trials (diabetes n=55; HIV n=59; hypertension n=18) were included. Key offspring data were frequently not reported, for example, number of births (diabetes: 22/55, 40%; HIV: 14/59, 24%; hypertension: 10/18, 56%). Congenital malformations were often not reported with sufficient detail (diabetes: 40/55, 73%; HIV: 39/59, 66%; hypertension: 17/18, 94%). Similar observations were made for other key items (eg, fetal losses, neonatal deaths).Conclusion: Under-reporting of key data for the offspring was frequent in publications of clinical trials in pregnant women with diabetes, HIV infection or hypertension making the assessment of the benefit-risk ratio of treatment options during pregnancy difficult.Trial Registration Number: CRD42017057024. [ABSTRACT FROM AUTHOR]

Glomerular diseases are leading causes of end‐stage renal disease in children. Tacrolimus is frequently used off‐label in the treatment of glomerular diseases. The effectiveness, safety and pharmacokinetic data of tacrolimus in the treatment of glomerular diseases in children are reviewed in this paper to provide evidence to support its rational use in clinical practice. The remission rates in previously published studies were different. In 19 clinical trials on children with nephrotic syndrome, the overall remission rate was 52.6‐97.6%. In four clinical trials on children with lupus nephritis, the overall remission rate was 81.8‐89.5%. In a pilot study with paediatric Henoch‐Schönlein purpura nephritis patients, the overall remission rate was 100.0%. Infection, nephrotoxicity, gastrointestinal symptoms and hypertension are the most common adverse events. Body weight, age, CYP3A5 genotype, cystatin‐C and daily dose of tacrolimus may have significant effects on the pharmacokinetics of tacrolimus in children with glomerular disease. More prospective controlled trials with long follow‐up are needed to demonstrate definitely the effectiveness, safety and pharmacokinetics of tacrolimus in children with glomerular diseases. [ABSTRACT FROM AUTHOR]

Objectives: In the absence of consensus, the present meta-analysis was performed to determine an optimal dosing regimen of vancomycin for neonates.Methods: A 'meta-model' with 4894 concentrations from 1631 neonates was built using NONMEM, and Monte Carlo simulations were performed to design an optimal intermittent infusion, aiming to reach a target AUC0-24 of 400 mg·h/L at steady-state in at least 80% of neonates.Results: A two-compartment model best fitted the data. Current weight, postmenstrual age (PMA) and serum creatinine were the significant covariates for CL. After model validation, simulations showed that a loading dose (25 mg/kg) and a maintenance dose (15 mg/kg q12h if <35 weeks PMA and 15 mg/kg q8h if ≥35 weeks PMA) achieved the AUC0-24 target earlier than a standard 'Blue Book' dosage regimen in >89% of the treated patients.Conclusions: The results of a population meta-analysis of vancomycin data have been used to develop a new dosing regimen for neonatal use and to assist in the design of the model-based, multinational European trial, NeoVanc. [ABSTRACT FROM AUTHOR]

Background: Eye drop treatment routinely used to obtain mydriasis prior to fundoscopy in neonates requires repeated instillations of mydriatic agents that can lead to systemic side effects. Objectives: The aim of this study was to compare the mydriatic efficacy and tolerance of administration of phenylephrine and tropicamide via the ophthalmic insert Mydriasert® versus standard eye drop treatment in neonates. Methods: In this prospective, single-blinded, noninferiority study, 80 hospitalized neonates (age < 18 months) requiring bilateral fundus examination were randomized to receive eye drops (repeated instillations of 2.5% phenylephrine and 0.5% tropicamide) or the insert. The primary outcome was mydriasis suitable for fundoscopy 75 min after mydriatic agent introduction (T75). Results: Mydriasis was successfully achieved in both eyes at T75 in 97.5% (n = 39/40) of the insert group patients versus 90% (n = 36/40) receiving eye drops (between-group difference 7.5%, demonstrating noninferiority). Mydriasis remained stable in 60.0% of patients (n = 24/40) in the insert group versus 15% (n = 6/40) in the eye drop group (p < 0.0001). The insert group required fewer nursing interventions than the eye drop group (p = 0.0001). Mean blood pressure were significantly higher in the insert versus the eye drop group (p < 0.0001 and p = 0.0003, respectively); mean heart rate was not significantly different between the groups (p = 0.37). In the insert group, 2 patients reported an adverse event (bradycardia, n = 1, and gastroesophageal reflux, n = 1; both appeared to be related to neonate pathology). Conclusions: The degree of mydriasis achieved with Mydriasert® was noninferior to that obtained with eye drops. The insert appears to be safe to use in neonates without a history of increased vagal tone or gastrointestinal reflux. [ABSTRACT FROM AUTHOR]

Beta cell function, measured as the average C-peptide response to a mixed meal (CP SB AVE sb ), is commonly used to assess the effectiveness of immune therapy in recent-onset type 1 diabetes. A similar pattern for CP SB EST sb was also observed, although CP SB EST sb was significantly higher than CP SB AVE sb at 3, 6 and 12 months. [Extracted from the article]

Objectives: Early target attainment is the key factor influencing the outcome of antimicrobial therapy. The objective of the present study was to evaluate the relationship between azithromycin concentrations during the first 24-48 h of therapy and the clinical outcome in order to optimize antimicrobial therapy.Methods: All children with lower respiratory tract infections receiving intravenous azithromycin monotherapy were included. The relationship between azithromycin trough concentrations during the first 24-48 h and the effectiveness and safety was explored.Results: Data from 44 children [mean (SD) age = 5.25 (3.72) years] were available for final analysis. Children with trough concentrations >0.25 mg/L (n = 8) had a more significant improvement in antibacterial efficacy in terms of decreased C-reactive protein (P = 0.006) and the percentage of neutrophils (P = 0.043) compared with children with trough concentrations ≤0.25 mg/L (n = 36). No drug-related adverse events were shown to have a causal association with azithromycin therapy.Conclusions: Our study showed the clinical benefits of early target attainment of azithromycin therapy. A target trough concentration of 0.25 mg/L in the first 24-48 h of hospitalization was required to ensure better antibacterial efficacy. [ABSTRACT FROM AUTHOR]

Abstract: Growth and maturation changes are mainly responsible for differences in drug pharmacokinetics and pharmacodynamics observed between adults and children, especially neonates. Ontogeny of drug‐metabolizing enzymes and transporters plays an important role in drugs interindividual pharmacokinetic variability but data are limited in both term and preterm neonates. This study aimed to characterize mRNA expression of the main drug‐metabolizing enzymes and transport proteins involved in drug disposition, using umbilical cord blood (UCB), according to gender, gestational age, and genetic background. A large panel of genes was quantified as follows: cytochrome P450 system (n = 12), UGT family (n = 6), TPMT and transporters (n = 3), in 56 samples of UCB of twin neonates. Gene expression was measured using real‐time reverse transcription polymerase chain reaction with 18S rRNA as the endogenous control for normalization of data. Relative expression of the samples was expressed using the 2−ΔΔCt method for comparison of gene expression levels. Twenty genes were expressed in UCB at birth with variable levels of expression and tissue‐specific gene expression when compared to data on the fetal liver. Gestational age, gender, and genetic background influenced the expression of the genes tested. Easily accessible UCB samples will enable further studies to evaluate the influence of covariates. This suggests that these covariates need to be considered when assessing substrate drugs disposition mediated by these metabolizing enzymes and transporters in the neonatal population. [ABSTRACT FROM AUTHOR]

Background: Tacrolimus is used off-label in the treatment of Henoch-Schönlein purpura nephritis (HSPN) in children, with limited evidence-based data. Based on clinical empirical experience and mechanism of action, tacrolimus might be promoted as treatment for childhood HSPN. The objectives of this pilot study were to assess its effectiveness and safety, and to explore the potential impact of CYP3A5 genotype.Methods: Children with HSPN receiving tacrolimus as empirical treatment were included in this prospective, observational study. Effectiveness was classified as complete remission, partial remission or non-response. General safety data analyses during and after study drug exposure included adverse events, reasons for discontinuation, deaths, laboratory data and vital signs. Trough concentration was determined using high-performance liquid chromatography with tandem mass spectrometry. Pharmacogenetic analysis was performed on the CYP3A5 gene.Results: A total of 20 patients with a mean age of 7.5 (SD 2.1) years participated in the whole process of the study. Twelve patients reached complete remission and eight patients reached partial remission at the end of 6-month treatment. No patients discontinued tacrolimus treatment due to adverse events, and no drug-related adverse events were shown to have a causal association with tacrolimus therapy. Dose-adjusted trough concentration was significantly higher in children with CYP3A5*1 allele as compared with patients with CYP3A5*3/*3 genotype (170.7±100.9 vs 79.8±47.4 (ng/mL)/(mg/kg)).Conclusion: This pilot study showed that tacrolimus might be an effective and well-tolerated drug for the treatment of HSPN in children. CYP3A5 polymorphism had a significant impact on tacrolimus concentration. [ABSTRACT FROM AUTHOR]

Aims: Nephrotic syndrome (NS) is the most common clinical manifestation of glomerular disease in children. Currently, tacrolimus (TAC) is widely used in children with NS. However, pharmacokinetic data in children with nephrotic syndrome is limited. This study was intended to evaluate the population pharmacokinetics (PPK) of TAC in paediatric NS and to optimize dosing regimen. Methods: Blood samples from NS children treated with TAC were collected and the blood concentrations of TAC were detected using HPLC‐MS/MS. A PPK model was developed using NONMEM software. Pharmacogenetic analysis was carried out in the CYP3A5 gene. Results: The data from 28 children were used for PPK analysis. A one‐compartment model and first‐order elimination were accorded with the TAC data in paediatric NS. A covariate analysis showed that body weight and CYP3A5 genotype significantly affected TAC pharmacokinetics. Monte Carlo simulation indicated that NS children with CYP3A5*3/*3 receiving 0.10 mg kg−1 dose−1 twice daily and NS children with CYP3A5*1 receiving 0.25 mg kg−1 dose−1 twice daily TAC could achieve the target concentrations of 5–10 ng ml−1. Conclusion: The PPK of TAC was estimated in children with NS and a CYP3A5 genotype‐based dosing regimen was set up based on simulations. [ABSTRACT FROM AUTHOR]

Objectives: Parental consent for the participation of their neonate in neonatal research is influenced by the quality of the information delivered and the interaction between parents and investigators. Failure to provide important information may lead to difficulties in the decision making process of parents. This Delphi survey aims to establish a consensus between parent representatives of neonatal associations and healthcare professionals concerning the information deemed essential by both parties in order to improve the recruitment of neonates into clinical trials. Method: This study was conducted in Europe among parent representatives and healthcare professionals. In this 3-phase study, 96 items were defined by the Scientific Committee (CS), composed of 11 clinicians (from 8 countries) and 1 parent representative of the European network of neonatal associations. Then the Committee of Experts (CE) composed of 16 clinicians were matched by country with 16 national parent representatives and evaluated these items in two rounds. The importance of each item was evaluated by each member of the CE on a scale between 1 and 9 based on their personal experience. Results: Fifty eight items reached the second and final level of consensus. In contrast to clinicians, parent representatives preferred to be informed about the study by the physician in charge of their child. They also favoured additional support during the informed consent process and stated that both parents need to agree and sign. Conclusion: The set of 58 items on which parents and clinicians reached consensus will be helpful to healthcare professionals seeking parental consent for the inclusion of a neonate in a clinical trial. Providing parents with information about the trial by the investigator in the presence of the patient’s neonatologist, developing closer contacts with parents and informing them of the available support by parents associations may be helpful for parents. [ABSTRACT FROM AUTHOR]

Background: Post-transplant diabetes mellitus (PTDM) is a major complication of immunosuppressive therapy, with many risk factors reported in adults with renal transplantation. The objective of this study was to investigate potential non-genetic and genetic risk factors of PTDM in children with renal transplantation treated with tacrolimus.Methods: A national database was screened for patients developing PTDM within 4 years following tacrolimus introduction. PTDM was defined as glucose disorder requiring anti-diabetic treatment. PTDM patients were matched to “non-PTDM” control transplanted children according to age, gender, and duration of post-transplant follow-up. Patients were genotyped for six selected genetic variants in POR*28 (rs1057868), PPARa (rs4253728), CYP3A5 (rs776746), VDR (rs2228570 and rs731236), and ABCB1 (rs1045642) genes, implicated in glucose homeostasis and tacrolimus disposition.Results: Among the 98 children with renal transplantation enrolled in this multicentre study, 18 developed PTDM. None of the clinical and biological parameters was significant between PTDM and control patients. Homozygous carriers of POR*28 or wild-type ABCB1 (rs1045642) gene variants were more frequent in PTDM than in control patients with differences close to significance (p = 0.114 and p = 0.066 respectively). A genetic score based on these variants demonstrated that POR*28/*28 and ABCB1 CC or CT genotype carriers were at a significantly higher risk of developing PTDM after renal transplantation.Conclusion: Identification of PTDM risk factors should allow clinicians to allocate the best immunosuppressant for each patient with renal transplantation, and improve care for patients who are at a higher risk. [ABSTRACT FROM AUTHOR]

Background Multicenter neonatal clinical trials aim to provide evidence-based drug evaluation, but recruiting neonates requires collaboration, standard procedures, and trained neonatologists. Methods A questionnaire based on a previous Delphi study was sent to European neonatal intensive care units (NICUs) to collect their research experience and identify areas for improvement. Results Of 247 NICUs,79 (32%) responded: 69 were level III units and 10 were level II units. In level III centers, 62% had medical staff dedicated to research and 65% conducted regular in-house audits. Similarities were observed in the median number of trials peryear(level II: 2; level III: 5), Good Clinical Practice training (level II: 78%; level III: 66%), and standard operating procedures (level II: 63%; level III: 71%). Most NICUs had access to scientific advice for trial design, conduct, data management, and regulatory aspects. Involvement of patient advocacy groups was more common in level II units (level II: 75%; level III: 59%). A "quality" score of 34 "quality" research items was calculated for all centers (mean: 23.2 ± 6.2; range: 6-34). Conclusion Research experience and processes vary across Europe. Harmonizing research practices and setting standards will allow building a European neonatal network for effective, safe, and quality neonatal drug development. [ABSTRACT FROM AUTHOR]

Aims: Although substantial progress has been made in understanding of ontogeny of drug metabolism, there is still a gap of knowledge in developmental pharmacogenetics in neonates. We hypothesized that both age and pharmacogenetics might explain the developmental pattern of CYP2C19. We conducted a population pharmacokinetic–pharmacogenetic study to quantify the developmental pharmacogenetics of CYP2C19 in neonates and young infants using omeprazole as a probe drug. Methods: Pharmacokinetic samples were collected from 51 Caucasian neonates and young infants, who were receiving omeprazole treatment. Population pharmacokinetic–pharmacogenetic analysis of omeprazole and its metabolites was performed using NONMEM. Results: Data fitted a one‐compartment parent and metabolite model with first‐order absorption and elimination. CYP2C19 and CYP3A4 are predominantly involved in the metabolism of omeprazole despite their relatively low activities compared to adults. The clearance of omeprazole converted to 5‐hydroxy‐omeprazole (CLOMZ‐M1) increases with postnatal age. In CYP2C19 poor and intermediate metabolizers, model‐predicted CLOMZ‐M1 are 12.5% (5–95% percentile: 3–14.9%) and 44.9% (5–95% percentile: 29.9–72.6%) of the value in extensive/ultrarapid metabolizer, respectively. Model‐predicted absorption rate constant of omeprazole is 6.93 (5–95% percentile: 3.01–14.61) times higher in ABCB1 homozygous mutant patients, 1.86 (5–95% percentile: 0.86–3.47) times higher in ABCB1 heterozygous patients than that in ABCB1 homozygous wild‐type patients. Conclusions: Developmental pharmacogenetics of CYP2C19 was quantitatively described in neonates and young infants using omeprazole as a probe drug. Our findings emphasize the importance of semiphysiological developmental pharmacokinetic modelling approach when evaluating developmental pharmacogenetics of drugs with multiple routes of biotransformation. [ABSTRACT FROM AUTHOR]

As more new drugs are discovered, traditional designs come at their limits. Ten years after the adoption of the European Paediatric Regulation, we performed a systematic review on the US National Library of Medicine and Excerpta Medica database of sequential trials involving newborns. Out of 326 identified scientific reports, 21 trials were included. They enrolled 2832 patients, of whom 2099 were analyzed: the median number of neonates included per trial was 48 (IQR 22-87), median gestational age was 28.7 (IQR 27.9-30.9) weeks. Eighteen trials used sequential techniques to determine sample size, while 3 used continual reassessment methods for dose-finding. In 16 studies reporting sufficient data, the sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674) with respect to a traditional trial. When the number of neonates finally included in the analysis was considered, the difference became significant: 35 (57%) patients (IQR 10 to 136.5, p = 0.0033).Conclusion: Sequential trial designs have not been frequently used in Neonatology. They might potentially be able to reduce the number of patients in drug trials, although this is not always the case. What is known: • In evaluating rare diseases in fragile populations, traditional designs come at their limits. About 20% of pediatric trials are discontinued, mainly because of recruitment problems. What is new: • Sequential trials involving newborns were infrequently used and only a few (n = 21) are available for analysis. • The sequential design allowed to non-significantly reduce the number of enrolled neonates by a median of 24 (31%) patients (IQR - 4.75 to 136.5, p = 0.0674). [ABSTRACT FROM AUTHOR]

Aims: Inflammation and organ failure have been reported to have an impact on cytochrome P450 (CYP) 3A‐mediated clearance of midazolam in critically ill children. Our aim was to evaluate a previously developed population pharmacokinetic model both in critically ill children and other populations, in order to allow the model to be used to guide dosing in clinical practice. Methods: The model was evaluated externally in 136 individuals, including (pre)term neonates, infants, children and adults (body weight 0.77–90 kg, C‐reactive protein level 0.1–341 mg l–1 and 0–4 failing organs) using graphical and numerical diagnostics. Results: The pharmacokinetic model predicted midazolam clearance and plasma concentrations without bias in postoperative or critically ill paediatric patients and term neonates [median prediction error (MPE) <30%]. Using the model for extrapolation resulted in well‐predicted clearance values in critically ill and healthy adults (MPE <30%), while clearance in preterm neonates was over predicted (MPE >180%). Conclusion: The recently published pharmacokinetic model for midazolam, quantifying the influence of maturation, inflammation and organ failure in children, yields unbiased clearance predictions and can therefore be used for dosing instructions in term neonates, children and adults with varying levels of critical illness, including healthy adults, but not for extrapolation to preterm neonates. [ABSTRACT FROM AUTHOR]

Background: Progress in immunosuppression has reduced acute rejection, graft loss and mortality after renal transplantation. Adverse drug reactions are well described in adults but few data are available in children. Our objectives were to analyse the adverse events reported in the first 3 years post-transplantation in children receiving tacrolimus or cyclosporine-based immunosuppression and compare them with the information of the Summary of Product Characteristics.Methods: This retrospective study included all children who underwent a renal transplant at Hospital Robert Debré between 2002 and 2015. Initial immunosuppression was based on induction, calcineurin inhibitor, mycophenolate mofetil and corticosteroids. Adverse events were collected from medical records and coded using the Medical Dictionary for Regulatory Activities and the implications of tacrolimus and cyclosporine analysed. Statistical analyses were performed using SAS 9.4.Results: One hundred and twenty-five children were included. During the observation period [2.7 years (0.6–4.3)], 105 patients received tacrolimus and 39 received cyclosporine. The incidence rate for gastrointestinal disorders was 0.128 and 0.056 by patient-years of exposure (p < 0.05), under tacrolimus and cyclosporine schedules. For neutropenia, it was 0.064 and 0.014 (p < 0.05). The frequencies of toxic nephropathy and gastrointestinal pain were higher than those in the Summary of Product Characteristics of tacrolimus (> 20%) and cyclosporine (> 10%). Cosmetic events for cyclosporine and neutropenia for tacrolimus were frequently observed (18 and 14.3%, respectively), although uncommon in the Summary of Product Characteristics.Conclusions: The exposure-adjusted incidence rate of gastrointestinal disorders and neutropenia was higher in children under the tacrolimus schedule. Our findings contribute to the evaluation of the benefit-risk balance of immunosuppressive therapy following paediatric renal transplantation. [ABSTRACT FROM AUTHOR]

Background: Polycystic ovary syndrome (PCOS) is more frequently observed in type 1 diabetes mellitus (T1DM) adult women than in nondiabetic women. No such prevalence has yet been studied in adolescent girls with T1DM. Aim: The aim of this study was to evaluate the prevalence of PCOS in adolescent girls with T1DM and to determine the clinical and hormonal features associated with the disorder. Methods: A cross-sectional study of 53 adolescent girls (gynecological age >2 years) referred for routine evaluation for T1DM was conducted. We diagnosed PCOS using the National Institutes of Health (NIH) and Rotterdam criteria. Results: 26.4 and 47.9% of adolescents had PCOS according to NIH (NIH-PCOS) and Rotterdam (Rotterdam-PCOS) criteria. 66.7% of NIH-PCOS adolescents had a complete phenotype associated with hyperandrogenism, oligomenorrhea, and polycystic ovarian morphology, unlike only 33.3% of the Rotterdam-PCOS adolescents. A family history of type 2 diabetes mellitus (T2DM) was more frequent in PCOS than in non-PCOS girls, whichever criteria were used. Late pubertal development and a T1DM diagnosis close to puberty were factors associated with NIH-PCOS. Conclusion: Adolescents with T1DM had a high prevalence of PCOS. More differences between PCOS and non-PCOS patients were found using the NIH criteria, suggesting that clinical characteristics might be more accurate for diagnosing PCOS in girls with T1DM. A family history of T2DM is associated with a high risk of PCOS. [ABSTRACT FROM AUTHOR]

Aim The objectives of this study were to characterize age-related changes in lamivudine pharmacokinetics in children and evaluate lamivudine exposure, followed by dose recommendations for subgroups in which target steady state area under the daily plasma concentration-time curve (AUC0-24h) is not reached. Methods Population pharmacokinetic modelling was performed in NONMEM using data from two model-building datasets and two external datasets [ n = 180 (age 0.4-18 years, body weight 3.4-60.5 kg); 2061 samples (median 12 per child); daily oral dose 60-300 mg (3.9-17.6 mg kg-1)]. Steady state AUC0-24h was calculated per individual (adult target 8.9 mg·h l-1). Results A two-compartment model with sequential zero order and first order absorption best described the data. Apparent clearance and central volume of distribution (% RSE) were 13.2 l h-1 (4.2%) and 38.9 l (7.0%) for a median individual of 16.6 kg, respectively. Bodyweight was identified as covariate on apparent clearance and volume of distribution using power functions (exponents 0.506 (20.2%) and 0.489 (32.3%), respectively). The external evaluation supported the predictive ability of the final model. In 94.5% and 35.8% of the children with a body weight >14 kg and <14 kg, respectively, the target AUC0-24h was reached. Conclusion Bodyweight best predicted the developmental changes in apparent lamivudine clearance and volume of distribution. For children aged 5 months-18 years with a body weight <14 kg, the dose should be increased from 8 to 10 mg kg-1 day-1 if the adult target for AUC0-24h is aimed for. In order to identify whether bodyweight influences bioavailability, clearance and/or volume of distribution, future analysis including data on intravenously administered lamivudine is needed. [ABSTRACT FROM AUTHOR]

Background: Despite specific initiatives and identified needs, most neonatal drugs are still used off-label, with variable dosage administrations and schedules. In high risk preterm and term neonates, drug evaluation is challenging and randomized controlled trials (RCT) are difficult to conduct and even more is the use of a placebo, required in the absence of a reference validated drug to be used as comparator. Methods: We analyzed the complete ClinicalTrials.gov registry 1) to describe neonatal RCT involving a placebo, 2) to report on the medical context and ethical aspects of placebo use. Results: Placebo versus drug RCT (n = 146), either prevention trials (n = 57, 39%) or therapeutic interventions (n = 89, 61%), represent more than a third of neonatal trials registered in the National Institute of Health clinical trial database (USA) since 1999. They mainly concerned preterm infants, evaluating complications of prematurity. Most trials were conducted in the USA, were single centered, and funded by non-profit organizations. For the three top drug trials evaluating steroids (n = 13, 9.6%), erythropoietin (EPO, n = 10, 6.8%) and nitric oxide (NO, n = 9, 6.2%), the objectives of the trial and follow-up were analyzed in more details. Conclusion: Although a matter of debate, the use of placebo should be promoted in neonates to evaluate a potential new treatment, in the absence of reference drug. Analysis of the trials evaluating steroids showed that long-term follow-up of exposed patients, although required by international guidelines, is frequently missing and should be planned to collect additional information and optimize drug evaluation in these high-risk patients. [ABSTRACT FROM AUTHOR]

Objective: Proton pump inhibitors are frequently administered on clinical symptoms in neonates but benefit remains controversial. Clinical trials validating omeprazole dosage in neonates are limited. The objective of this trial was to determine the minimum effective dose (MED) of omeprazole to treat pathological acid reflux in neonates using reflux index as surrogate marker. Design: Double blind dose-finding trial with continual reassessment method of individual dose administration using a Bayesian approach, aiming to select drug dose as close as possible to the predefined target level of efficacy (with a credibility interval of 95%). Setting: Neonatal Intensive Care unit of the Robert Debré University Hospital in Paris, France. Patients: Neonates with a postmenstrual age ≥ 35 weeks and a pathologic 24-hour intra-esophageal pH monitoring defined by a reflux index ≥ 5% over 24 hours were considered for participation. Recruitment was stratified to 3 groups according to gestational age at birth. Intervention: Five preselected doses of oral omeprazole from 1 to 3 mg/kg/day. Main outcome measures: Primary outcome, measured at 35 weeks postmenstrual age or more, was a reflux index <5% during the 24-h pH monitoring registered 72±24 hours after omeprazole initiation. Results: Fifty-four neonates with a reflux index ranging from 5.06 to 27.7% were included. Median age was 37.5 days and median postmenstrual age was 36 weeks. In neonates born at less than 32 weeks of GA (n = 30), the MED was 2.5mg/kg/day with an estimated mean posterior probability of success of 97.7% (95% credibility interval: 90.3–99.7%). The MED was 1mg/kg/day for neonates born at more than 32 GA (n = 24). Conclusions: Omeprazole is extensively prescribed on clinical symptoms but efficacy is not demonstrated while safety concerns do exist. When treatment is required, the daily dose needs to be validated in preterm and term neonates. Optimal doses of omeprazole to increase gastric pH and decrease reflux index below 5% over 24 hours, determined using an adaptive Bayesian design differ among neonates. Both gestational and postnatal ages account for these differences but their differential impact on omeprazole doses remains to be determined. [ABSTRACT FROM AUTHOR]

Background/Aims: To evaluate the efficacy and safety of a triptorelin pamoate (11.25 mg) 3-month formulation in the management of central precocious puberty (CPP) (TP Study) and to retrospectively compare it with a triptorelin acetate (11.25 mg) 3-month formulation (TA Study). Methods: We conducted two phase III, multicentre, single-stage, non-comparative, open-label studies. In the TP Study, patients with CPP received an intramuscular injection of triptorelin pamoate 11.25 mg at baseline and 3 months after baseline. Hormonal changes as well as safety and efficacy endpoints were measured at baseline, 3 months, and 6 months. Results: The baseline characteristics of the 37 patients in the TP Study were similar to those of the TA Study population. A suppressed luteinising hormone (LH) response (LH peak 빝 3 IU/l) to the gonadotrophin-releasing hormone test at 3 months (primary endpoint) occurred in 83.8 and 82.8% of the cases in the TP and the TA Study, respectively. At 6 months, a suppressed LH response occurred in 86.5 and 96.8% of the cases in the TP and the TA Study, respectively. Pubertal development was slowed in both studies. Adverse events were mild to moderate and resolved without sequelae in the TP Study. Conclusion: Triptorelin pamoate 11.25 mg administered at 3-month intervals is an effective and well-tolerated treatment in patients with CPP. The efficacy and safety profiles appear similar to those reported in the literature for triptorelin acetate 11.25 mg. [ABSTRACT FROM AUTHOR]

Aim Term and preterm neonates are at high risk for serious adverse drug reactions (ADRs). Methods A descriptive study of reports registered in the French pharmacovigilance database from 1986 to 2012 were obtained. All reports concerning neonates (≤1 month of life) with direct drug exposure were retrieved. Characteristics of the reports, including reported ADR(s), drug(s) and the causality assessment using the French causality assessment method, were described. Results A total of 1688 reports were analyzed and more than half of them were classified as serious ( n = 995). Median age at ADR occurrence was 9 days. Overall, 3127 ADRs were described in these reports in relation to 2238 suspect/interacting drugs. The most commonly reported system organ classes (SOCs) were injury, poisoning and procedural complications (16%), general disorders and administration site conditions (12.5%) and blood and lymphatic system disorders (12%). In the majority of ADRs reported (73%), infants fully recovered and less than 4% of neonates deceased as a consequence of the reported ADR. One out of five ADRs was associated with drug administration errors. Therapeutic classes commonly incriminated were anti-infectives, nervous system and alimentary tract drugs. Substances most frequently related to serious ADRs were zidovudine, ibuprofen and nevirapine. Among the 10 most frequently encountered drug−ADR pairs, two substances were mainly implicated, zidovudine in haematological adverse reactions and phytomenadione in maladministrations. Conclusions Anti-infective drugs, mainly antiretroviral therapy, account for the majority of ADRs reported in neonates. The specific issue of drug maladministration and medication errors remains to be addressed in neonates. [ABSTRACT FROM AUTHOR]

Background and Objective: The use of an opportunistic (also called scavenged) sampling strategy in a prospective pharmacokinetic study combined with population pharmacokinetic modelling has been proposed as an alternative strategy to conventional methods for accomplishing pharmacokinetic studies in neonates. However, the reliability of this approach in this particular paediatric population has not been evaluated. The objective of the present study was to evaluate the performance of an opportunistic sampling strategy for a population pharmacokinetic estimation, as well as dose prediction, and compare this strategy with a predetermined pharmacokinetic sampling approach.Methods: Three population pharmacokinetic models were derived for ciprofloxacin from opportunistic blood samples (SC model), predetermined (i.e. scheduled) samples (TR model) and all samples (full model used to previously characterize ciprofloxacin pharmacokinetics), using NONMEM software. The predictive performance of developed models was evaluated in an independent group of patients.Results: Pharmacokinetic data from 60 newborns were obtained with a total of 430 samples available for analysis; 265 collected at predetermined times and 165 that were scavenged from those obtained as part of clinical care. All datasets were fit using a two-compartment model with first-order elimination. The SC model could identify the most significant covariates and provided reasonable estimates of population pharmacokinetic parameters (clearance and steady-state volume of distribution) compared with the TR and full models. Their predictive performances were further confirmed in an external validation by Bayesian estimation, and showed similar results. Monte Carlo simulation based on area under the concentration-time curve from zero to 24 h (AUC24)/minimum inhibitory concentration (MIC) using either the SC or the TR model gave similar dose prediction for ciprofloxacin.Conclusion: Blood samples scavenged in the course of caring for neonates can be used to estimate ciprofloxacin pharmacokinetic parameters and therapeutic dose requirements. [ABSTRACT FROM AUTHOR]

Aim Children with haematological malignancy represent an identified subgroup of the paediatric population with specific pharmacokinetic parameters. In these patients, inadequate empirical antibacterial therapy may result in infection-related morbidity and increased mortality, making optimization of the dosing regimen essential. As paediatric data are limited, our aim was to evaluate the population pharmacokinetics of teicoplanin in order to define the appropriate dosing regimen in this high risk population. Methods The current dose of teicoplanin was evaluated in children with haematological malignancy. Population pharmacokinetics of teicoplanin were analyzed using nonmem software. The dosing regimen was optimized based on the final model. Results Eighty-five children (age range 0.5 to 16.9 years) were included. Therapeutic drug monitoring and opportunistic samples ( n = 143) were available for analysis. With the current recommended dose of 10 mg kg-1 day-1, 41 children (48%) had sub-therapeutic steady-state trough concentrations ( Css,min<10 mg l-1). A two compartment pharmacokinetic model with first order elimination was developed. Systematic covariate analysis identified that bodyweight (size) and creatinine clearance significantly influenced teicoplanin clearance. The model was validated internally. Its predictive performance was further confirmed in an external validation. In order to reach the target AUC of 750 mg l-1 h 18 mg kg-1 was required for infants, 14 mg kg-1 for children and 12 mg kg-1 for adolescents. A patient-tailored dose regimen was further developed and reduced variability in AUC and Css,min values compared with the mg kg-1 basis dose, making the modelling approach an important tool for dosing individualization. Conclusions This first population pharmacokinetic study of teicoplanin in children with haematological malignancy provided evidence-based support to individualize teicoplanin therapy in this vulnerable population. [ABSTRACT FROM AUTHOR]

In neonates, vancomycin, a narrow-spectrum antibiotic, is the first choice of treatment of late-onset sepsis predominantly caused by Gram-positive bacteria (coagulase-negative staphylococci and enterococci). Although it has been used for >50 years, prescribing the right dose and dosing regimen remains a challenge in neonatal intensive care units for many reasons including high pharmacokinetic variability, increase in the minimal inhibition concentration against staphylococci, lack of consensus on dosing regimen and way of administration (continuous or intermittent), duration of treatment, use of therapeutic drug monitoring, limited data on short- and long-term toxicity, risk of mutant selection and errors of administration linked to concentrated formulations. This article highlights and discusses future research directions, with specific attention given to dosing optimization of vancomycin, including the advantages of modeling and simulation approaches. [ABSTRACT FROM AUTHOR]

The objective of the present study was to review the available pharmacokinetic evidence for the utility of cystatin C (CysC) as a marker of renal function to predict the dose of renally excreted drugs.The bibliographic search used PubMed and EMBASE databases, from its inception through to January 2014, with the following keywords 'pharmacokinetics' and 'cystatin C'.Sixteen pharmacokinetic publications were identified and seven drugs primarily excreted by the kidney were studied. Among them, only one study was performed in children, the others were performed in adults and/or elderly subjects, either healthy volunteers or patients with variable clinical conditions, such as cystic fibrosis and cancer. Most of studies ( n = 13/16) demonstrated that CysC was better correlated with clearance/trough concentration of evaluated drugs compared with creatinine.Our review supports that CysC is a good marker of renal function to predict dose of renally excreted drugs. Efforts should be made to evaluate the impact of CysC in special populations in order to define its clinical value in dosing optimization. [ABSTRACT FROM AUTHOR]

Objective: This survey aims to describe and analyse the dosage regimens of antibiotics in French neonatal intensive care units (NICUs). Methods: Senior doctors from 56 French NICUs were contacted by telephone and/or email to provide their local guidelines for antibiotic therapy. Results: 44 (79%) NICUs agreed to participate in this survey. In total, 444 dosage regimens were identified in French NICUs for 4 1 antibiotics. The number of different dosage regimens varied from 1 to 32 per drug (mean 9, SD 7.8). 37% of intravenous dosage regimens used a unique mg/kg dose from preterm to full-term neonates. Doses and/or dosing intervals varied significantly for 12 antibiotics (amikacin, gentamicin, netilmicin, tobramycin, vancomycin administered as continuous infusion, ceftazidime, cloxacillin, oxacillin, penicillin G, imipenem/ cilastatin, clindamycin and metronidazole). Among these antibiotics, 6 were used in more than 70% of local guidelines and had significant variations in (1) maintenance daily doses for amikacin, imipenem/ cilastatin, ceftazidime and metronidazole; (2) loading doses for continuous infusion of vancomycin; and (3) dosing intervals for gentamicin and amikacin. Conclusions: A considerable inter-centre variability of dosage regimens of antibiotics exists in French NICUs. Developmental pharmacokinetic-pharmacodynamic studies are essential for the evaluation of antibiotics in order to establish evidence-based dosage regimens for effective and safe administration in neonates. [ABSTRACT FROM AUTHOR]

Choosing the right dose of tacrolimus 'adapted to each individual patient' is a central question after transplantation. The pharmacokinetic behaviour of tacrolimus in paediatric patients is significantly influenced by clinical factors growth and maturation, as well as genetic factors. Large interindividual variability and narrow therapeutic index make dosage individualisation mandatory in children. CYP3A5 expressers require a 1.8-fold higher tacrolimus dose than non-expressers. A visual patient-tailored dosing chart, taking into consideration the child's weight, recent haematocrit level and CYP3A5 genotype, was developed based on a population pharmacokinetic--pharmacogenetic model, and can be used routinely to individualise tacrolimus starting dose. Area under the concentration-time curve-based dosage adaptation through limited sampling strategy and Bayesian estimation is more reliable than trough concentration. Therapeutic drug monitoring and dosage adaptation can be included in routine post-transplantation consultation and should be considered in the urgent situations (eg, rejection, adverse event, lack of compliance, change of coadministration drug with potential drug-drug interaction and other situations). [ABSTRACT FROM AUTHOR]

Background: Anti-tuberculosis drug induced hepatotoxicity (ATDH) is a major adverse drug reaction associated for anti-tuberculosis therapy. The glutathione S-transferases (GST) plays a crucial role in the detoxification of hepatotoxic metabolites of anti-tuberculosis drugs.An association between GSTM1/GSTT1 null mutations and increased risk of ATDH has been demonstrated in adults. Given the ethnic differences and developmental changes, our study aims to investigate the potential impacts of GSTM1/GSTT1genotypes on the development of ATDH in Han Chinese children treated with anti-tuberculosis therapy. Methods: Children receiving anti-tuberculosis therapy with or without evidence of ATDH were considered as the cases or controls, respectively. The GSTM1 and GSTT1 genotyping were performed using the polymerase chain reaction. Results: One hundred sixty-three children (20 cases and 143 controls) with a mean age of 4.7 years (range: 2 months-14.1 years) were included. For the GSTM1, 14 (70.0%) cases and 96 (67.1%) controls had homozygous null mutations. For the GSTT1, 13 (65.0%) cases and 97 (67.8%) controls had homozygous null mutations. Neither the GSTM1, nor the GSTT1 polymorphism was significantly correlated with the occurrence of ATHD. Conclusion: Ourresults did not support the GSTM1 and GSTT1 polymorphisms as the predictors of ADTH in Chinese Han children treated with anti-tuberculosis drugs. An age-related association between pharmacogenetics and ATHD need to be confirmed in the further study. [ABSTRACT FROM AUTHOR]

Background: Idiopathic nephrotic syndrome (INS) is likely a primary immune disorder, but viruses might also be involved in the mechanisms of the disease. Here, we investigate the link between herpesvirus infection and the first manifestation of INS in children. Methods: A prospective, multicentre, and population-based case-control study called NEPHROVIR included 164 patients, aged 6 months to 15 years old, newly diagnosed with INS, and 233 controls matched for gender, age, and period of sample. The analysis was done on 124 patients and 196 controls. Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 (HHV-6), and human herpesvirus-7 (HHV-7) DNA prevalence at diagnosis were assessed from whole peripheral blood samples, as well as EBV and CMV viral load and seroprevalence. Results: EBV DNA was significantly more prevalent in cases than in controls (50.8 vs 29.1 %; OR = 2.6; p = 0.0002), with no difference in viral load. A significant difference was also found for CMV (11.3 vs 3.6 %; p = 0.02) and HHV-7 (83 vs 72 %; p = 0.02) DNA prevalence between cases and controls. There were significantly more EBV and CMV recent infections or reactivations based on VCA-IgM and CMV IgM in cases than controls, while there were no differences in IgG seroprevalence. Conclusion: The prevalence of positive EBV DNA detection and recent infection or reactivation is higher in children at onset of INS compared to a population matched for age, gender, and time of sampling. [ABSTRACT FROM AUTHOR]

Background and objectives: Selection of the first-dose-in-neonates is challenging. The objective of this proof-of-concept study was to evaluate a pharmacokinetic bridging approach to predict a neonatal dosing regimen. Methods: We selected fluconazole as a paradigm compound. We used data from studies in juvenile mice and adults to develop population pharmacokinetic models using NONMEM. We also develop a physiologically-based pharmacokinetic model from in vitro-in silico data using Simcyp. These three models were then used to predict neonatal pharmacokinetics and dosing regimens for fluconazole. Results: From juvenile mice to neonates, a correction factor of maximum lifespan potential should be used for extrapolation, while a 'renal factor' taking into account renal maturation was required for successful bridging based on adult and in vitro-in silico data. Simulations results demonstrated that the predicted drug exposure based on bridging approach was comparable to the observed value in neonates. The prediction errors were −2.2, +10.1 and −4.6 % for juvenile mice, adults and in vitro-in silico data, respectively. Conclusion: A model-based bridging approach provided consistent predictions of fluconazole pharmacokinetic parameters in neonates and demonstrated the feasibility of this approach to justify the first-dose-in-neonates, based on all data available from different sources (including physiological informations, preclinical studies and adult data), allowing evidence-based decisions of neonatal dose rather than empiricism. [ABSTRACT FROM AUTHOR]