Factors and Mechanisms for Pharmacokinetic Differences between Pediatric Population and Adults

Cytochrome P450: Polymorphisms and Roles in Cancer, Diabetes and Atherosclerosis

Cytochromes P450s (CYPs) constitute a superfamily of enzymes that catalyze the metabolism of drugs and other substances. Endogenous substrates of CYPs include eicosanoids, estradiol, arachidonic acids, cholesterol, vitamin D and neurotransmitters. Exogenous substrates of CYPs include the polycyclic aromatic hydrocarbons and about 80% of currently used drugs. Some isoforms can activate procarcinogens to ultimate carcinogens. Genetic polymorphisms of CYPs may affect the enzyme catalytic activity and have been reported among different populations to be associated with various diseases and adverse drug reactions. With regard of drug metabolism, phenotypes for CYP polymorphism range from ultrarapid to poor metabolizers. In this review, we discuss some of the most clinically important CYPs isoforms (CYP2D6, CYP2A6, CYP2C19, CYP2C9, CYP1B1 and CYP1A2) with respect to gene polymorphisms and drug metabolism. Moreover, we review the role of CYPs in renal, lung, breast and prostate cancers and also discuss their significance for atherosclerosis and type 2 diabetes mellitus.

A pharmacokinetic model for amiodarone in infants developed from an opportunistic sampling trial and published literature data

Amiodarone is a first-line antiarrhythmic for life-threatening ventricular fibrillation or ventricular tachycardia in children, yet little is known about its pharmacokinetics (PK) in this population. We developed a population PK (PopPK) model using samples collected via an opportunistic study design of children receiving amiodarone per standard of care supplemented by amiodarone PK data from the literature. Both study data and literature data were predominantly from infants < 2 years old, so our analysis was restricted to this group. The final combined dataset consisted of 266 plasma drug concentrations in 45 subjects with a median (interquartile range) postnatal age of 40.1 (11.0-120.4) days and weight of 3.9 (3.1-5.1) kg. Since the median sampling time after the first dose was short (study: 95 h; literature: 72 h) relative to the terminal half-life estimated in adult PopPK studies, values of the deep compartment volume and flow were fixed to literature values. A 3-compartment model best described the data and was validated by visual predictive checks and non-parametric bootstrap analysis. The final model included body weight as a covariate on all volumes and on both inter-compartmental and elimination clearances. The empiric Bayesian estimates for clearance (CL), volume of distribution at steady state, and terminal half-life were 0.25 (90% CL 0.14-0.36) L/kg/h, 93 (68-174) L/kg, and 266 (197-477) h, respectively. These studies will provide useful information for future PopPK studies of amiodarone in infants and children that could improve dosage regimens.

Efficacy and safety of ascending doses of praziquantel against Schistosoma haematobium infection in preschool-aged and school-aged children: a single-blind randomised controlled trial

BACKGROUND

Despite decades of experience with praziquantel treatment in school-aged children (SAC) and adults, we still face considerable knowledge gaps relevant to the successful treatment of preschool-aged children (PSAC). This study aimed to assess the efficacy and safety of escalating praziquantel dosages in PSAC infected with Schistosoma haematobium.

METHODS

We conducted a randomised, dose-finding trial in PSAC (2-5 years) and as comparator a cohort of SAC (6-15 years) infected with S. haematobium in Côte d'Ivoire. A total of 186 PSAC and 195 SAC were randomly assigned to 20, 40 or 60 mg/kg praziquantel or placebo. The nature of the dose-response relationship in terms of cure rate (CR) was the primary objective. Egg reduction rate (ERR) and tolerability were secondary outcomes. CRs and ERRs were assessed using triplicate urine filtration over 3 consecutive days. Available-case analysis was performed including all participants with primary endpoint data.

RESULTS

A total of 170 PSAC and 174 SAC received treatment. Almost 90% of PSAC and three quarters of SAC were lightly infected with S. haematobium. Follow-up data were available for 157 PSAC and 166 SAC. In PSAC, CRs of praziquantel were 85.7% (30/35), 78.0% (32/41) and 68.3% (28/41) at 20, 40 and 60 mg/kg and 47.5% (19/40) for placebo. In SAC, CRs were 10.8% for placebo (4/37), 55.6% for 20 mg/kg (25/45), 68.3% for 40 mg/kg (28/41) and 60.5% for 60 mg/kg (26/43). ERRs based on geometric means ranged between 96.5% (60 mg/kg) and 98.3% (20 mg/kg) in PSAC and between 97.6% (20 mg/kg and 60 mg/kg) and 98.6% (40 mg/kg) in SAC. Adverse events were mild and transient.

CONCLUSIONS

Praziquantel revealed dose-independent efficacy against light infections of S. haematobium. Over the dose range tested, praziquantel displayed a ceiling effect with the highest response for 20 mg/kg in PSAC. In SAC maximum efficacy was obtained with 40 mg/kg praziquantel. Further investigations are required in children with moderate to heavy infections.

TRIAL REGISTRATION

This trial is registered with International Standard Randomised Controlled Trial Number ISRCTN15280205 .

Reference Intervals for Urinary Cotinine Levels and the Influence of Sampling Time and Other Predictors on Its Excretion Among Italian Schoolchildren

(1) Background: Environmental Tobacco Smoke (ETS) exposure remains a public health problem worldwide. The aims are to establish urinary (u-) cotinine reference values for healthy Italian children, to evaluate the role of the sampling time and of other factors on children’s u-cotinine excretion. (2) Methods: A cross-sectional study was performed on 330 children. Information on participants was gathered by a questionnaire and u-cotinine was determined in two samples for each child, collected during the evening and the next morning. (3) Results: Reference intervals (as the 2.5th and 97.5th percentiles of the distribution) in evening and morning samples were respectively equal to 0.98–4.29 and 0.91–4.50 µg L⁻¹ (ETS unexposed) and 1.39–16.34 and 1.49–20.95 µg L⁻¹ (ETS exposed). No statistical differences were recovered between median values found in evening and morning samples, both in ETS unexposed and exposed. Significant predictors of u-cotinine excretions were ponderal status according to body mass index of children (β = 0.202; p-value = 0.041 for evening samples; β = 0.169; p-value = 0.039 for morning samples) and paternal educational level (β = −0.258; p-value = 0.010; for evening samples; β = −0.013; p-value = 0.003 for morning samples). (4) Conclusions: The results evidenced the need of further studies for assessing the role of confounding factors on ETS exposure, and the necessity of educational interventions on smokers for rising their awareness about ETS.

Pharmacokinetic considerations for pediatric patients receiving analgesia in the intensive care unit; targeting postoperative, ECMO and hypothermia patients

INTRODUCTION

Adequate postoperative analgesia in pediatric patients in the intensive care unit (ICU) matters, since untreated pain is associated with negative outcomes. Compared to routine postoperative patients, children undergoing hypothermia (HT) or extracorporeal membrane oxygenation (ECMO), or recovering after cardiac surgery likely display non-maturational differences in pharmacokinetics (PK) and pharmacodynamics (PD). These differences warrant additional dosing recommendations to optimize pain treatment. Areas covered: Specific populations within the ICU will be discussed with respect to expected variations in PK and PD for various analgesics. We hereby move beyond maturational changes and focus on why PK/PD may be different in children undergoing HT, ECMO or cardiac surgery. We provide a stepwise manner to develop PK-based dosing regimens using population PK approaches in these populations. Expert opinion: A one-dose to size-fits-all for analgesia is suboptimal, but for several commonly used analgesics the impact of HT, ECMO or cardiac surgery on average PK parameters in children is not yet sufficiently known. Parameters considering both maturational and non-maturational covariates are important to develop population PK-based dosing advices as part of a strategy to optimize pain treatment.

Efficacy and safety of praziquantel in preschool-aged and school-aged children infected with Schistosoma mansoni: a randomised controlled, parallel-group, dose-ranging, phase 2 trial

Background

Praziquantel has been the drug of choice for schistosomiasis control for more than 40 years, yet surprisingly, the optimal dose for children younger than 4 years is not known. We aimed to assess the efficacy and safety of escalating praziquantel dosages in preschool-aged children (PSAC).

Methods

We did a randomised controlled, parallel-group, single-blind, dose-ranging, phase 2 trial in PSAC (2–5 years) and school-aged children (SAC; aged 6–15 years) as a comparator group in southern Côte d'Ivoire. Children were randomly assigned (1:1:1:1) to 20 mg/kg, 40 mg/kg, or 60 mg/kg praziquantel or placebo. Participants, investigators, and laboratory technicians were masked to group assignment, while the investigator providing treatment was aware of the treatment group. The primary objective was to estimate the nature of the dose–response relation in terms of cure rate using the Kato Katz technique. Dose–response curves were estimated using E_max models. Available case analysis was done including all participants with primary endpoint data. This trial is registered with International Standard Randomised Controlled Trial, number ISRCTN15280205.

Findings

Between Nov 11, 2014, and Feb 18, 2015, 660 PSAC and 225 SAC were assessed for eligibility; of whom 161 (24%) PSAC and 180 (80%) SAC had a detectable Schistosoma mansoni infection. 161 PSAC were randomly allocated of whom 154 received treatment: 42 were assigned to 20 mg/kg praziquantel, of whom 40 received treatment; 38 were assigned to 40 mg/kg praziquantel, of whom 38 received treatment; 41 were assigned to 60 mg/kg praziquantel, of whom 39 received treatment; and 40 were assigned to placebo, of whom 37 received placebo. 180 SAC were randomly allocated of whom 177 received treatment: 49 were assigned to 20 mg/kg praziquantel, of whom 47 received treatment; 46 were assigned to 40 mg/kg praziquantel, of whom 46 received treatment; 42 were assigned to 60 mg/kg praziquantel, of whom 42 received treatment; and 43 were assigned to placebo, of whom 43 received treatment. Follow-up (available-case) data were available for 143 PSAC and 174 SAC. In PSAC, the 20 mg/kg dose resulted in cure in 23 children (62%; 95% CI 44·8–77·5), 40 mg/kg in 26 children (72%; 54·8–85·8), 60 mg/kg in 25 children (71%; 53·7–85·4), and placebo in 13 children (37%; 21·5–55·1). In SAC, the 20 mg/kg dose resulted in cure in 14 children (30%; 95% CI 17·7–45·8), 40 mg/kg in 31 children (69%; 53·4–81·8), 60 mg/kg in 34 children (83%; 67·9–92·8), and placebo in five children (12%; 4·0–25·6). For both age groups, the number of adverse events was similar among the three praziquantel treatment groups, with fewer adverse events observed in the placebo groups. The most common adverse events in PSAC were diarrhoea (11 [9%] of 124) and stomach ache (ten [8%]) and in SAC were diarrhoea (50 [28%] of 177), stomach ache (66 [37%]), and vomiting (26 [15%]) 3 h post treatment. No serious adverse events were reported.

Interpretation

Praziquantel shows a flat dose-response and overall lower efficacy in PSAC compared with in SAC. In the absence of treatment alternatives, a single dose of praziquantel of 40 mg/kg, recommended by the WHO for S mansoni infections in SAC can be endorsed for PSAC in preventive chemotherapy programmes.

Funding

European Research Council.

Computerized pediatric oncology prescriptions review by pharmacist: A descriptive analysis and associated risk factors

BACKGROUND

Systematic prescription analyses by clinical pharmacists result in pharmacist interventions (PIs) to reduce prescription errors and improve medication safety. PIs are particularly critical in oncology, because antineoplastic drugs are highly toxic with low therapeutic indexes especially in a pediatric population. The aim of this study is to describe PIs in a pediatric oncology department and to identify potential risk factors associated with prescription errors.

PROCEDURE

We conducted a 20-month observational study in a pediatric oncology department concerning electronic prescription of injectable chemotherapies was conducted. PIs were analyzed for drug-related problems (DRPs), type of intervention, population characteristics, involved drugs, and the potential risk factors.

RESULTS

Clinical pharmacists made 90 PIs for 10,214 antineoplastic prescriptions for a rate of 88 PIs per 10,000 prescriptions. The majority of DRPs were dosage errors (61.8%), imputable to measurements (weight and/or height) in 47.4% or unreported dose reduction. The most common patient ages were in the range 1-10 years and the most common time for medical double checks was 2-9 pm. There were statistically more prescription errors in standardized protocols (P < 0.001).

CONCLUSIONS

Not surprisingly, PIs were predominantly to correct dose errors, half of which related to height and weight measurements that were not updated. No significant risk factors for errors were identified for errors except in the standardized status of prescription, which appears to be linked in part to our software that did not automatically reflect dose reduction from one course to the next. Medical double-checking followed by a clinical pharmacist's double check were effective in order to prevent prescription errors.

Challenges Caring for Adults With Congenital Heart Disease in Pediatric Settings: How Nurses Can Aid in the Transition

As surgery for complex congenital heart disease is becoming more advanced, an increasing number of patients are surviving into adulthood, yet many of these adult patients remain in the pediatric hospital system. Caring for adult patients is often a challenge for pediatric nurses, because the nurses have less experience and comfort with adult care, medications, comorbid conditions, and rehabilitation techniques. As these patients age, the increased risk of complications and comorbid conditions from their heart disease may complicate their care further. Although these patients are admitted on a pediatric unit, nurses can aid in promoting their independence and help prepare them to transition into the adult medical system. Nurses, the comprehensive medical teams, and patients' families can all effectively influence the process of preparing these patients for transition to adult care.

Drugs Being Eliminated via the Same Pathway Will Not Always Require Similar Pediatric Dose Adjustments

For scaling drug plasma clearance (CLp) from adults to children, extrapolations of population pharmacokinetic (PopPK) covariate models between drugs sharing an elimination pathway have enabled accelerated development of pediatric models and dosing recommendations. This study aims at identifying conditions for which this approach consistently leads to accurate pathway specific CLp scaling from adults to children for drugs undergoing hepatic metabolism. A physiologically based pharmacokinetic (PBPK) simulation workflow utilizing mechanistic equations defining hepatic metabolism was developed. We found that drugs eliminated via the same pathway require similar pediatric dose adjustments only in specific cases, depending on drugs extraction ratio, unbound fraction, type of binding plasma protein, and the fraction metabolized by the isoenzyme pathway for which CLp is scaled. Overall, between‐drug extrapolation of pediatric covariate functions for CLp is mostly applicable to low and intermediate extraction ratio drugs eliminated by one isoenzyme and binding to human serum albumin in children older than 1 month.

Infantil delirium induced by cycloplegic eye drops

Cyclopentolate 1% and tropicamide 1% eye drops are considered to be safe in the pediatric population for the fundus examination and treatment of ocular diseases. Although adverse reactions rarely occur, some of them can be life-threatening such as seizure, delirium, coma, arrhythmia, acute life-threatening event, and death. Here we report 15 months old boy who developed delirium after administration of ocular cyclopentolate 1% drops in both eyes during a routine examination for retinopathy of prematurity. Cyclopentolate is a parasympatholytic drug with actions similar to atropine. With ophthalmic administration of cyclopentolate, severe central nervous system effects and systemic reactions may occur. In order to minimize absorption following instill one or two drops of 1% solution, applying pressure to nasolacrimal sac for 2 to 3 min should be considered. In mild to moderate toxicity, benzodiazepines may be used to control central nervous system findings secondary to anticholinergic effects.

Evaluating Clinical Effectiveness and Pharmacokinetic Profile of Atomized Intranasal Midazolam in Children Undergoing Laceration Repair

BACKGROUND

Atomized intranasal midazolam is a common adjunct in pediatrics for procedural anxiolysis. There are no previous studies of validated anxiety scores with pharmacokinetic data to support optimal procedure timing.

OBJECTIVES

We describe the clinical and pharmacokinetic profile of atomized intranasal midazolam in children presenting for laceration repair.

METHODS

Children 11 months to 7 years of age and weighing <26 kg received 0.4 mg/kg of atomized intranasal midazolam for simple laceration repair. Blood samples were obtained at 3 time points in each patient, and the data were fit with a 1-compartment model. Patient anxiety was rated with the Observational Scale of Behavioral Distress. Secondary outcomes included use of adjunctive medications, successful completion of procedure, and adverse events.

RESULTS

Sixty-two subjects were enrolled, with a mean age of 3.3 years. The median time to peak midazolam concentration was 10.1 min (interquartile range 9.7-10.8 min), and the median time to the procedure was 26 min (interquartile range 21-34 min). There was a trend in higher Observational Scale of Behavioral Distress scores during the procedure. We observed a total of 2 adverse events, 1 episode of vomiting (1.6%) and 1 paradoxical reaction (1.6%). Procedural completion was successful in 97% of patients.

CONCLUSIONS

Atomized intranasal midazolam is a safe and effective anxiolytic to facilitate laceration repair. The plasma concentration was >90% of the maximum from 5 to 17 min, suggesting this as an ideal procedural timeframe after intranasal midazolam administration.

Pharmacokinetic changes of antibiotic, antiviral, antituberculosis and antifungal agents during extracorporeal membrane oxygenation in critically ill adult patients

WHAT IS KNOWN AND OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) is a life-saving system used for critically ill patients with cardiac and/or respiratory failure. The pharmacokinetics (PK) of drugs can change in patients undergoing ECMO, which can result in therapeutic failure or drug toxicity requiring further management of drug complications. In this review, we discussed changes in the PK of antibiotic, antiviral, antituberculosis and antifungal agents administered to adult patients on ECMO. These drugs are crucial for managing infections, which commonly occur during ECMO.

METHODS

A literature search was conducted using the PubMed and EMBASE databases with the following keywords: "extracorporeal membrane oxygenation OR extracorporeal membrane oxygenations OR ECMO" and "PK OR pharmacokinetics OR pharmacokinetic*" and "anti infective* OR antibiotic* OR antiviral* OR antituberculosis OR antifungal*."

RESULTS AND DISCUSSION

Generally, the volume of distribution (Vd) increases and drug clearance (CL) and elimination decrease during ECMO. Highly significant changes in drug PK can occur by interactions with the ECMO device itself, drug characteristics, pathological changes and patient characteristics. This may affect the blood concentrations of drugs, which influence the success of therapy. The PK of vancomycin, piperacillin-tazobactam, meropenem, azithromycin, amikacin and caspofungin did not change significantly in adult patients receiving ECMO. However, there were significant changes in the PK of imipenem, oseltamivir, rifampicin and voriconazole. The trough concentrations of imipenem were highly variable; oseltamivir had a decreased CL and increased Vd, and rifampicin concentrations were below therapeutic levels, even when a higher-than-standard dose was used in patients treated with ECMO. Additionally, voriconazole exhibited high mean peak concentrations during ECMO.

WHAT IS NEW AND CONCLUSION

The impact of ECMO on PK varies among drugs in adult patients, and there is no consistent correlation between the effects observed in adult and infant studies. This review suggested that doses of imipenem, oseltamivir, rifampicin and voriconazole should be adjusted and therapeutic drug monitoring is needed when ECMO is used in adult patients. In the future, large PK trials in adults on ECMO are needed to provide optimal dosing guidelines. A PK/PD modelling approach will be useful for determining the precise impact of ECMO and other factors that contribute to PK changes for each drug. Finally, it is important to develop dosing guidelines based on PK/PD modelling studies that can be used in clinical practice.

Pharmacokinetics and Pharmacokinetic/Pharmacodynamic Relationships of Etravirine in HIV-1-Infected, Treatment-Experienced Children and Adolescents in PIANO

PIANO (NCT00665847) investigated etravirine pharmacokinetics, efficacy, and safety in children and adolescents. Treatment-experienced, HIV-1-infected patients (≥6 to <18 years) received etravirine 5.2 mg/kg twice daily (maximum 200 mg twice daily) plus background antiretrovirals. A population pharmacokinetic model was developed, and etravirine C_0h and AUC_0-12h were estimated. Relationships among intrinsic/extrinsic factors and etravirine pharmacokinetics and pharmacokinetics with pharmacodynamics were assessed. The best model describing etravirine pharmacokinetics consisted of a single compartment with sequential zero- and first-order absorption following a lag time. Interindividual variability terms were included on clearance (CL/F) and the first-order input rate constant (KA). The final model estimates (coefficient of variation, %) for CL/F and KA were 46.3 (11) L/h and 1.07 (34) h^-1 , respectively. Overall, median (range) estimated etravirine C_0h and AUC_0-12h were 287 (2-2276) ng/mL and 4560 (62-28,865) ng · h/mL, respectively. Exposure was slightly lower in adolescents vs children. Sex and adherence did not affect etravirine pharmacokinetics. Factors significantly affecting etravirine exposure were body weight (higher with lower weight), race (lower in Asians than in white or black patients), and the use of certain HIV protease inhibitors. Virologic response (<50 copies/mL at week 48) was lower in the lowest etravirine AUC_0-12h quartile vs the upper 3 quartiles (41% vs 67% to 76%). Rash occurred more frequently in the highest quartile than in the lower 3 quartiles (52% versus 8% to 20%). Etravirine 5.2 mg/kg twice daily in treatment-experienced, HIV-1-infected children and adolescents provides comparable exposure to that in adults receiving etravirine 200 mg twice daily and is the recommended dose for children and adolescents.

Efficacy and safety of inhaled corticosteroids relative to fluticasone propionate: a systematic review of randomized controlled trials in asthma

INTRODUCTION

Many trials have been published comparing inhaled corticosteroid (ICS) treatments in asthma. However, mixed results necessitate the summarization of available evidence to aid in decision-making. Areas covered: This systematic review evaluated randomized controlled trials (RCTs) that compared the efficacy and safety of inhaled fluticasone propionate (FP) with other ICS including beclomethasone dipropionate (BDP), budesonide (BUD) and ciclesonide (CIC). PubMed was searched and 54 RCTs that fit pre-determined criteria were included. Endpoints evaluated included lung function, asthma symptom control, exacerbation frequency, reliever use, quality of life and steroid-related side effects. Expert commentary: Across all studies, FP was associated with either more favorable or at least similar efficacy and safety, in comparison with BDP or BUD. This observation may be related to FP's higher relative potency and almost negligible oral bioavailability. FP was comparable to CIC for efficacy. However, CIC appeared to have a smaller impact on cortisol levels than FP, which is likely due to CIC's incomplete conversion to active metabolite (des-CIC) and the lower potency of des-CIC compared with FP. Although there were no significant differences in evaluated outcomes after treatment with different ICS in the majority of studies, some observed differences could be explained by their respective pharmacodynamic and pharmacokinetic properties.

Adjusting ferritin concentrations for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project

Background: The accurate estimation of iron deficiency is important in planning and implementing interventions. Ferritin is recommended as the primary measure of iron status, but interpretability is challenging in settings with infection and inflammation.Objective: We assessed the relation between ferritin concentrations and inflammation and malaria in preschool children (PSC) (age range: 6-59 mo) and women of reproductive age (WRA) (age range: 15-49 y) and investigated adjustment algorithms to account for these effects.Design: Cross-sectional data from 15 surveys for PSC (n = 27,865) and 8 surveys for WRA (24,844), from the Biomarkers Reflecting the Inflammation and Nutritional Determinants of Anemia (BRINDA) project were analyzed individually and combined with the use of a meta-analysis. Several approaches were explored to estimate depleted iron stores (ferritin concentration <12 μg/L in PSC and <15 μg/L in WRA) in inflammation and malaria settings as follows: 1) increase ferritin-concentration cutoff to <30 μg/L; 2) exclude individuals with C-reactive protein (CRP) concentrations >5 mg/L or α-1-acid glycoprotein (AGP) concentrations >1 g/L; 3) apply arithmetic correction factors; and 4) use a regression correction approach.Results: Depleted iron-store estimates incrementally increased as CRP and AGP deciles decreased (4% compared with 30%, and 6% compared with 29% from highest compared with lowest CRP deciles for pooled PSC and WRA, respectively, with similar results for AGP). Depending on the approach used to adjust for inflammation (CRP plus AGP), the estimated prevalence of depleted iron stores increased by 7-25 and 2-8 absolute median percentage points for PSC and WRA, respectively, compared with unadjusted values. Adjustment for malaria in addition to CRP and AGP did not substantially change the estimated prevalence of depleted iron stores.Conclusions: Our results lend support for the use of internal regression correction to estimate the prevalence of depleted iron stores in regions with inflammation. This approach appears to mathematically reflect the linear relation of ferritin concentrations with acute-phase proteins. More research is warranted to validate the proposed approaches, but this study contributes to the evidence base to guide decisions about how and when to adjust ferritin for inflammation.

[Profile of clinical trials enrolling Brazilian children]

This study aimed to characterize the clinical trials with medicines enrolling Brazilian children and adolescents, registered in the databases of Clinical Trials and the Brazilian Clinical Trials Network (ReBEC) from 1994 to 2014. Only 462 clinical trials enrolled Brazilian children and adolescents. There was an increase in registrations beginning in 2003, with an important drop in 2011. Among these trials, 35.5% were hosted in Brazil. The international clinical trials were mostly conducted by North American companies. In both cases, multinational industry was the principal source of funding. The clinical trials were predominantly phase III with injectable and solid oral pharmaceutical forms of antiviral drugs. Domestic clinical trials showed wider variation in the pharmaceutical forms and higher percentage of liquid formulations, when compared to the international trials. In addition to heavy external dependence for conducting clinical trials, the study emphasized the challenge for pediatric care in Brazil, which presents epidemiological peculiarities in an environment prone to the use of unlicensed medicines for children.

Metabolomic analysis for the study of maturation in pediatrics: Effect of confounding factors in a pilot study

A pilot study for the investigation of the maturation grade of children has been carried out using plasma samples already analyzed in a previous pharmacokinetic study. By using a meticulous data treatment, possible confounding factors that may hinder the obtained results were identified. By doing so, it was possible to obtain enough evidence to support the feasibility of performing a larger study eluding some unwanted variability and minimizing not only the number of subjects involved but also the time and money spent on the study. In the pilot study the metabolic profiles obtained using UHPLC-TOF-MS technique of plasma samples from 14 newborn piglets (<5 days) were compared with the plasma profiles of 16 infant piglets (8 weeks). The type of anaesthesia administered, gender, vein or artery of blood extraction and time of sampling were studied as possible confounding factors. Unsupervised analysis by principal component analysis (PCA) clearly differentiated between neonates and children. During the data treatment and the statistical analysis, the effect of confounding factors such as the anaesthetic regimen was identified and removed, while the effect of the rest of studied factors was not considered relevant, and the discrimination between the two groups based on the age was maintained. This allowed extracting relevant conclusions for a future study design while avoiding the unnecessary sacrifice of animals. Furthermore, the results obtained demonstrate the utility of metabolomics in the discovery of novel putative plasma biomarkers such as carnitines that can be correlated with the maturation state of paediatric patients.

Food effects in paediatric medicines development for products Co-administered with food

A small amount of food is commonly used to aid administration of medicines to children to improve palatability and/or swallowability. However the impact of this co-administered food on the absorption and subsequent pharmacokinetic profile of the drug is unknown. Existing information on food effects is limited to standard protocols used to evaluate the impact of a high fat meal in an adult population using the adult medication. In the absence of a substantial body of data, there are no specific guidelines available during development of paediatric products relating to low volumes of potentially low calorie food. This paper brings together expertise to consider how the impact of co-administered food can be risk assessed during the development of a paediatric medicine. Two case studies were used to facilitate discussions and seek out commonalities in risk assessing paediatric products; these case studies used model drugs that differed in their solubility, a poorly soluble drug that demonstrated a positive food effect in adults and a highly soluble drug where a negative food effect was observed. For poorly soluble drugs risk assessments are centred upon understanding the impact of food on the in vivo solubility of the drug which requires knowledge of the composition of the food and the volumes present within the paediatric gastrointestinal tract. Further work is required to develop age appropriate in vitro and in silico models that are representative of paediatric populations. For soluble drugs it is more important to understand the mechanisms that may lead to a food effect, this may include interactions with transporters or the impact of the food composition on gastro-intestinal transit or even altered gastric motility. In silico models have the most promise for highly soluble drug products although it is essential that these models reflect the relevant mechanisms involved in potential food effects. The development of appropriate in vitro and in silico tools is limited by the lack of available clinical data that is critical to validate any tool. Further work is required to identify globally acceptable and available vehicles that should be the first option for co-administration with medicines to enable rapid and relevant risk assessment.

Risk factors for adverse drug reactions in pediatric inpatients: a systematic review

BACKGROUND

The main objective of the present systematic review is to identify potential risk factors for adverse drug reactions (ADRs) through prospective cohort studies in pediatric inpatients.

METHODS

The data search was done in the following electronic databases PubMed/MEDLINE; Scopus; LILACS and Web of Science from the earliest record until 31 May 2015. Two reviewers independently screened each study and one of them assessed the methodological quality according to the Newcastle-Ottawa scale for cohort studies. The data extraction was conducted according to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) initiative for cohort studies.

RESULTS

The only risk factor observed in all studies was the increase in the number of prescription drugs. However, other factors were identified, such as the increase in the length of stay or the number of low- or high-risk drugs prescribed, use of general anesthesia and oncological diagnosis. The cumulative incidence of ADR was 16.4% (95% confidence interval: 15.6 to 17.2). The main professional responsible for ADR identification was the pharmacist and the dominant category among the ADRs were gastrointestinal disorders. In addition, analgesics, antibacterial agents and corticosteroids were the drug classes commonly associated with ADRs. The methodology used in this study was tried to homogenize the data extracted; however, this was not sufficient to correct the discrepancies so it was not possible to perform a meta-analysis.

CONCLUSIONS

The increase in the number of prescription drugs was the main risk factor in this population. However, additional studies are required to identify the risk factors for ADRs in pediatric inpatients.

Age, Weight, and CYP2D6 Genotype Are Major Determinants of Primaquine Pharmacokinetics in African Children

Low-dose primaquine is recommended to prevent Plasmodium falciparum malaria transmission in areas threatened by artemisinin resistance and areas aiming for malaria elimination. Community treatment campaigns with artemisinin-based combination therapy in combination with the gametocytocidal primaquine dose target all age groups, but no studies thus far have assessed the pharmacokinetics of this gametocytocidal drug in African children. We recruited 40 children participating in a primaquine efficacy trial in Burkina Faso to study primaquine pharmacokinetics. These children received artemether-lumefantrine and either a 0.25- or a 0.40-mg/kg primaquine dose. Seven blood samples were collected from each participant for primaquine and carboxy-primaquine plasma levels determinations: one sample was collected before primaquine administration and six after primaquine administration according to partially overlapping sampling schedules. Physiological population pharmacokinetic modeling was used to assess the impact of weight, age, and CYP2D6 genotype on primaquine and carboxy-primaquine pharmacokinetics. Despite linear weight normalized dosing, the areas under the plasma concentration-time curves and the peak concentrations for both primaquine and carboxy-primaquine increased with age and body weight. Children who were CYP2D6 poor metabolizers had higher levels of the parent compound, indicating a lower primaquine CYP2D6-mediated metabolism. Our data indicate that primaquine and carboxy-primaquine pharmacokinetics are influenced by age, weight, and CYP2D6 genotype and suggest that dosing strategies may have to be reconsidered to maximize the transmission-blocking properties of primaquine. (This study has been registered at ClinicalTrials.gov under registration no. NCT01935882.)

Are age-appropriate antibiotic formulations missing from the WHO list of essential medicines for children? A comparison study

OBJECTIVE

There is a global call for formulations, which are better suited for children of different age categories and in a variety of settings. One key public health area of interest is age-appropriate paediatric antibiotics. We aimed to identify clinically relevant paediatric formulations of antibiotics listed on pertinent formularies that were not on the WHO Essential Medicines List for Children (EMLc).

METHODS

We compared four medicines lists versus the EMLc and contrasted paediatric antibiotic formulations in relation to administration routes, dosage forms and/or drug strengths. The additional formulations on comparator lists that differed from the EMLc formulations were evaluated for their added clinical values and costs.

RESULTS

The analysis was based on 26 EMLc antibiotics. Seven oral and two parenteral formulations were considered clinically relevant for paediatric use. Frequently quoted benefits of oral formulations included: filling the gap of unmet therapeutic needs in certain age/weight groups (phenoxymethylpenicillin and metronidazole oral liquids, and nitrofurantoin capsules), and simplified administration and supply advantages (amoxicillin dispersible tablets, clyndamycin capsules, cloxacillin tablets, and sulfamethoxazole+trimethoprim tablets). Lower doses of ampicillin and cefazolin powder for injection could simplify the dosing in newborns and infants, reduce the risk of medical errors, and decrease the waste of medicines, but may target only narrow age/weight groups.

CONCLUSIONS

The identified additional formulations of paediatric antibiotics on comparator lists may offer clinical benefits for low-resource settings, including simplified administration and increased dosing accuracy. The complexity of both procuring and managing multiple strengths and formulations also needs to be considered.

Optimising the use of medicines to reduce acute kidney injury in children and babies

The majority of medications in children are administered in an unlicensed or off-label manner. Paediatricians are obliged to prescribe using the limited evidence available. The 2007 EU regulation on the use of paediatric drugs means pharmaceutical companies are now obliged to (and receive incentives for) contributing to paediatric drug data and carrying out paediatric clinical trials. This is important, as the efficacy and adverse effect profiles of medicines vary across childhood. Additionally, there are significant age-related changes in the pharmacodynamic and pharmacokinetic activity of many drugs. This may be related to physiological (differential expressions of cytochrome P450 enzymes or variable glomerular filtration rates at different ages for example) and psychological (increasing autonomy and risk perception in teenage years) changes. Increasing numbers of children are surviving life-threatening childhood conditions due to medical advances. This means there is an increasing population who are at risk of the consequences of the long-term, early exposure to nephrotoxic agents. The kidney is an organ that is particularly vulnerable to damage as a consequence of drugs. Drug-induced acute kidney injury (AKI) episodes in children and babies are principally due to non-steroidal anti-inflammatory drugs, antibiotics or chemotherapeutic agents. The renal tubules are vulnerable to injury because of their concentrating ability and high-energy hypoxic environment. This review focuses on drug-induced AKI and the methods to minimise its effect, including general management plus the role of child-specific pharmacokinetic data, the use of pharmacogenomics and early detection of AKI using urinary biomarkers and electronic triggers.

Impact of disease, drug and patient adherence on the effectiveness of antiviral therapy in pediatric HIV

INTRODUCTION

Maintaining effective antiretroviral treatment for life is a major problem in both resource-limited and resource-rich countries. Despite the progress observed in paediatric antiretroviral therapy, approximately 12% of children still experience treatment failure due to drug resistance, inadequate dosing and poor adherence. We explore the current status of antiretroviral therapy in children with focus on the interaction between disease, drug pharmacokinetics and patient behavior, all of which are strongly interconnected and determine treatment outcome. Areas covered: An overview is provided of the viral characteristics and available drug combinations aimed at the prevention of resistance. In this context, the role of patient adherence is scrutinized. A detailed assessment of factors affecting adherence is presented together with the main strategies to enhance treatment response in children. Expert opinion: Using modeling and simulation, a framework for characterizing the forgiveness of non-adherence for specific antiretroviral drugs in children is proposed in which information on pharmacokinetics, pharmacokinetic-pharmacodynamic relationships and viral dynamics is integrated. This approach represents an opportunity for the simplification of dosing regimens taking into account the interaction between these factors. Based on clinical trial simulation scenarios, we envisage the possibility of assessing the impact of variable adherence to antiretroviral drug combinations in HIV-infected children.

Genetic Programming of Hypertension

The heritability of hypertension (HTN) is widely recognized and as a result, extensive studies ranging from genetic linkage analyses to genome-wide association studies are actively ongoing to elucidate the etiology of both monogenic and polygenic forms of HTN. Due to the complex nature of essential HTN, however, single genes affecting blood pressure (BP) variability remain difficult to isolate and identify and have rendered the development of single-gene targeted therapies challenging. The roles of other causative factors in modulating BP, such as gene-environment interactions and epigenetic factors, are increasingly being brought to the forefront. In this review, we discuss the various monogenic HTN syndromes and corresponding pathophysiologic mechanisms, the different methodologies employed in genetic studies of essential HTN, the mechanisms for epigenetic modulation of essential HTN, pharmacogenomics and HTN, and finally, recent advances in genetic studies of essential HTN in the pediatric population.

Cautious use and optimal dose of morphine for relieving malignant pain in a complex patient with multiple comorbidities

Oral morphine remains the drug of choice for the management of severe pain due to cancer as per WHO ladder of analgesia. Providing adequate pain relief in palliative care settings for pain due to cancer is challenging. Options become limited in cases of associated systemic comorbidities such as renal dysfunction, hypoproteinaemia, anaemia. Patients with renal dysfunction and other comorbidities may develop drug overdose due to abnormal pharmacokinetics. Renal dysfunction affects the pharmacokinetics of morphine by altering its absorption, metabolism and clearance. Plasma albumin also influences drug availability, its plasma distribution and thus available free morphine for its clinical effect. Morphine should be used cautiously for the treatment of pain in patients with renal failure, hypoproteinaemia, hyperbilirubinaemia and anaemia. In such patients, alternate opiates like fentanyl, hydromorphone, or oxycodone may be used as these drugs are not significantly excreted by the kidneys.

Efficacy, safety and drug survival of conventional agents in pediatric psoriasis: A multicenter, cohort study

The data on long-term efficacy, safety and drug survival rates of conventional systemic therapeutics in pediatric psoriasis is lacking. The primary aim of this study is to investigate acitretin, methotrexate, cyclosporin efficacy, safety and drug survival rates in pediatric patients as well as predictors of drug survival. This is a multicenter study including 289 pediatric cases being treated with acitretin, methotrexate and cyclosporin in four academic referral centers. Efficacy, adverse events, reasons for discontinuation, 1, 2- and 3-year drug survival rates, and determinants of drug survival were analyzed. A 75% reduction of Psoriasis Area and Severity Index score or better response rate was obtained in 47.5%, 34.1% and 40% of the patients who were treated with acitretin, methotrexate and cyclosporin, respectively. One-year drug survival rates for acitretin, methotrexate and cyclosporin were 36.3%, 21.1% and 15.1%, respectively. The most significant determinant of drug survival, which diminished over time, was treatment response whereas arthritis, body mass index and sex had no influence. Although all three medications are effective and relatively safe in children, drug survival rates are low due to safety concerns at this age group. Effective disease control through their rational use can be expected to improve survival rates.

Quality by design (QbD) approach of pharmacogenomics in drug designing and formulation development for optimization of drug delivery systems

Conventional approaches of drug discovery are very complex, costly and time consuming. But after the completion of human genome project, applications of pharmacogenomics in this area completely revolutionize the drug discovery and development process to produce a quality by design (QbD) approach based products. The applications of two areas of pharmacogenomics i.e. structural and functional pharmacogenomics excel the drug discovery process by employing genomic data in drug target identification and evaluation, lead optimization via high throughput screening, evaluation of drug metabolizing enzymes, drug transporters and drug receptors using computer aided technique and bioinformatics library data base. Pharmacogenomics also provides an important and reliable basis for evaluation and optimization of the dosage forms as well as repositioning of failed drugs for the treatment of new disease. Various dosage forms of category of drugs such as anticancer drugs, vaccines, gene and DNA delivery systems and immunological agents can be easily evaluated based on the genetic markers of the related disease. The effect of different formulation polymers on pharmacokinetic and pharmacodynamic properties of drugs can be assessed easily and therefore it plays an important role in formulation optimization. However, current applications of pharmacogenomics in drug discovery and formulation optimization are very limited because of costly and non accessible techniques for everyone, but in future, with the advancement in the technology; the application of genomic data in drug discovery will provide us with innovative, safer and more efficacious medicines.

An investigation of the mutagenic activity of salamide - a major impurity of hydrochlorothiazide

Hydrochlorothiazide is a widely used antihypertensive agent and one of its major impurities, salamide (4-amino-6-chlorobenzene-1,3-disulphonamide), has a chemical structure containing a primary amino group, a functional group that has previously been reported to be associated with carcinogenic activity. It is known that hydrochlorothiazide purity is a challenging problem for the pharmaceutical industry. As there were no prior mutagenicity data for the impurity salamide, the aim was to investigate its mutagenicity in this study. Salamide was tested for mutagenic potential in Salmonella typhimurium TA98, TA100, TA 1535, TA 1537, and E. coli WP2 uvrA + E. coli WP2 [pKM101] strains at six different concentrations, the highest concentration being the 5000 μg/plate. In both the presence and absence of the metabolic activation system, no mutagenic activity was observed. Results indicated that salamide should be classified as an ordinary impurity and controlled according to Q3A(R2) and Q3B(R2) guidelines.

The Role of Pharmacotherapy in the Treatment of Adolescent Substance Use Disorders

Adolescent substance use disorders (SUDs) are a significant public health issue due to the associated morbidity, mortality, and societal cost. While effective for some adolescents, psychosocial interventions generally produce small-to-moderate reductions in substance use. Most youth relapse within 12 months of treatment. One approach to improve outcomes is through adjunctive pharmacotherapy. Medication assisted treatments have been shown to improve adult SUD treatment outcomes, and preliminary studies in adolescents suggest that combining medication with psychosocial interventions may also enhance SUD outcomes for youth. This article presents a comprehensive review and grading of the evidence from studies conducted in adolescents with SUDs.

Towards a rational design of solid drug nanoparticles with optimised pharmacological properties

Solid drug nanoparticles (SDNs) are a nanotechnology with favourable characteristics to enhance drug delivery and improve the treatment of several diseases, showing benefit for improved oral bioavailability and injectable long‐acting medicines. The physicochemical properties and composition of nanoformulations can influence the absorption, distribution, and elimination of nanoparticles; consequently, the development of nanoparticles for drug delivery should consider the potential role of nanoparticle characteristics in the definition of pharmacokinetics. The aim of this study was to investigate the pharmacological behaviour of efavirenz SDNs and the identification of optimal nanoparticle properties and composition. Seventy‐seven efavirenz SDNs were included in the analysis. Cellular accumulation was evaluated in HepG2 (hepatic) and Caco‐2 (intestinal), CEM (lymphocyte), THP1 (monocyte), and A‐THP1 (macrophage) cell lines. Apparent intestinal permeability (P_app) was measured using a monolayer of Caco‐2 cells. The P_app values were used to evaluate the potential benefit on pharmacokinetics using a physiologically based pharmacokinetic model. The generated SDNs had an enhanced intestinal permeability and accumulation in different cell lines compared to the traditional formulation of efavirenz. Nanoparticle size and excipient choice influenced efavirenz apparent permeability and cellular accumulation, and this appeared to be cell line dependent. These findings represent a valuable platform for the design of SDNs, giving an empirical background for the selection of optimal nanoparticle characteristics and composition. Understanding how nanoparticle components and physicochemical properties influence pharmacological patterns will enable the rational design of SDNs with desirable pharmacokinetics.

Population Pharmacokinetics and Pharmacodynamics of Lumefantrine in Young Ugandan Children Treated With Artemether-Lumefantrine for Uncomplicated Malaria

Background. The pharmacokinetics and pharmacodynamics of lumefantrine, a component of the most widely used treatment for malaria, artemether-lumefantrine, has not been adequately characterized in young children.

Methods. Capillary whole-blood lumefantrine concentration and treatment outcomes were determined in 105 Ugandan children, ages 6 months to 2 years, who were treated for 249 episodes of Plasmodium falciparum malaria with artemether-lumefantrine.

Results. Population pharmacokinetics for lumefantrine used a 2-compartment open model with first-order absorption. Age had a significant positive correlation with bioavailability in a model that included allometric scaling. Children not receiving trimethoprim-sulfamethoxazole with capillary whole blood concentrations <200 ng/mL had a 3-fold higher hazard of 28-day recurrent parasitemia, compared with those with concentrations >200 ng/mL (P = .0007). However, for children receiving trimethoprim-sulfamethoxazole, the risk of recurrent parasitemia did not differ significantly on the basis of this threshold. Day 3 concentrations were a stronger predictor of 28-day recurrence than day 7 concentrations.

Conclusions. We demonstrate that age, in addition to weight, is a determinant of lumefantrine exposure, and in the absence of trimethoprim-sulfamethoxazole, lumefantrine exposure is a determinant of recurrent parasitemia. Exposure levels in children aged 6 months to 2 years was generally lower than levels published for older children and adults. Further refinement of artemether-lumefantrine dosing to improve exposure in infants and very young children may be warranted.

Rapid point-of-care identification of oral medications in gastric lavage content by ambient mass spectrometry in the emergency room

RATIONALE

Acute poisoning should be handled with high efficiency in order to minimize morbidity and mortality in the emergency room. Unfortunately, history-taking and physical examination are not always reliable. Mis-swallowing of oral medications is common in the pediatric group. This study aimed at developing a rapid point-of-care ambient mass spectrometric method for the early identification of ingested oral medications in gastric lavage content.

METHODS

Four different types of oral medications that are most commonly mis-swallowed by children were diluted to different concentrations. Each of these chemical solutions was mixed with human gastric lavage content. A direct metallic sampling probe was dipped into the solution. It was then inserted promptly into the thermal desorption electrospray ionization source to carry out ionization and subsequent mass spectrometric analysis of the medications. The corresponding compounds were identified through matching of the obtained mass spectrometric data with those provided by well-established databases.

RESULTS

Since no pretreatment of the specimen was required, the sampling step, and the subsequent thermal desorption electrospray ionization and mass spectrometric detection of the medications were completed within 30 s. Mass spectra were obtained for four different kinds of oral medication. The limit-of-detection of the four tested oral medications in gastric lavage content is at sub-ppm level, which is sensitive enough for emergency medicine applications since the quantities of medications ingested by pediatric patients are usually much higher.

CONCLUSIONS

Thermal desorption electrospray ionization mass spectrometry, with informational support provided by an online mass spectral database, allows for early point-of-care identification of mis-swallowed oral medications in the evacuated gastric lavage contents obtained from gastric lavage of patients in the emergency room, and it is promising in providing important toxicological information to ensure the appropriateness of the subsequent medical management. Copyright © 2016 John Wiley & Sons, Ltd.

Off-label use of rilpivirine in combination with emtricitabine and tenofovir in HIV-1-infected pediatric patients: A multicenter study

To assess the safety and efficacy of rilpivirine in combination with emtricitabine and tenofovir (RPV/FTC/TDF) as a once-daily single-tablet regimen (STR) in HIV-1-infected children and adolescents we performed a multicenter case series study of HIV-1-infected patients. Inclusion criteria were initiation of therapy with RPV/FTC/TDF before the age of 18. Patients were divided into undetectable viral load (uVL) group, HIV-1 RNA < 20 copies/mL on stable combined antiretroviral therapy (cART), and detectable viral load (dVL) group, HIV-1 RNA ≥ 20 copies/mL at RPV/FTC/TDF initiation. Patients were monitored from the date of RPV/FTC/TDF initiation until June 30, 2015, RPV/FTC/TDF discontinuation or failure to follow-up. Seventeen patients (8 in uVL and 9 in dVL group) with age between 11.6 and 17.6 were included. Reasons for switching were toxicity (n = 4) and simplification (n = 4) in uVL; viral failure (n = 8) and cART initiation (n = 1) in the dVL group. After a median follow-up of 90 (uVL) and 40 weeks (dVL), 7/8 (86%) patients maintained and 8/9 (89%) achieved and maintained HIV-1 suppression. Median CD4 count increased from 542 to 780/μL (uVL, P = 0.069) and 480 to 830/μL (dVL, P = 0.051). Five patients (2 in uVL and 3 in dVL) improved their immunological status from moderate to no immunosuppression. Serum lipid profiles improved in both groups; cholesterol dropped significantly in the dVL group (P = 0.008). Grade 1 laboratory adverse events (AEs) were observed in 3 patients. No clinical AEs occurred. Adherence was complete in 9 patients (5 in uVL and 4 in dVL); 1 adolescent interrupted treatment. Once-daily STR with RPV/FTC/TDF may be a safe and effective choice in selected HIV-1-infected adolescents and children.

Pediatric Biopharmaceutical Classification System: Using Age-Appropriate Initial Gastric Volume

Development of optimized pediatric formulations for oral administration can be challenging, time consuming, and financially intensive process. Since its inception, the biopharmaceutical classification system (BCS) has facilitated the development of oral drug formulations destined for adults. At least theoretically, the BCS principles are applied also to pediatrics. A comprehensive age-appropriate BCS has not been fully developed. The objective of this work was to provisionally classify oral drugs listed on the latest World Health Organization's Essential Medicines List for Children into an age-appropriate BCS. A total of 38 orally administered drugs were included in this classification. Dose numbers were calculated using age-appropriate initial gastric volume for neonates, 6-month-old infants, and children aging 1 year through adulthood. Using age-appropriate initial gastric volume and British National Formulary age-specific dosing recommendations in the calculation of dose numbers, the solubility classes shifted from low to high in pediatric subpopulations of 12 years and older for amoxicillin, 5 years, 12 years and older for cephalexin, 9 years and older for chloramphenicol, 3-4 years, 9-11 and 15 years and older for diazepam, 18 years and older (adult) for doxycycline and erythromycin, 8 years and older for phenobarbital, 10 years and older for prednisolone, and 15 years and older for trimethoprim. Pediatric biopharmaceutics are not fully understood where several knowledge gaps have been recently emphasized. The current biowaiver criteria are not suitable for safe application in all pediatric populations.

Discordant temporal development of bacterial phyla and the emergence of core in the fecal microbiota of young children

The colonization pattern of intestinal microbiota during childhood may impact health later in life, but children older than 1 year are poorly studied. We followed healthy children aged 1-4 years (n=28) for up to 12 months, during which a synbiotic intervention and occasional antibiotics intake occurred, and compared them with adults from the same region. Microbiota was quantified with the HITChip phylogenetic microarray and analyzed with linear mixed effects model and other statistical approaches. Synbiotic administration increased the stability of Actinobacteria and antibiotics decreased Clostridium cluster XIVa abundance. Bacterial diversity did not increase in 1- to 5-year-old children and remained significantly lower than in adults. Actinobacteria, Bacilli and Clostridium cluster IV retained child-like abundances, whereas some other groups were converting to adult-like profiles. Microbiota stability increased, with Bacteroidetes being the main contributor. The common core of microbiota in children increased with age from 18 to 25 highly abundant genus-level taxa, including several butyrate-producing organisms, and developed toward an adult-like composition. In conclusion, intestinal microbiota is not established before 5 years of age and diversity, core microbiota and different taxa are still developing toward adult-type configuration. Discordant development patterns of bacterial phyla may reflect physiological development steps in children.

Review of commonly used age-based weight estimates for paediatric drug dosing in relation to the pharmacokinetic properties of resuscitation drugs

AIM

To study which weight estimate calculation used in paediatric resuscitation results in optimal drug dosing; Advanced Paediatric and Life Support (APLS) or the UK Resuscitation Council age-based formula.

METHOD

Commonly used drugs used in paediatric resuscitation were selected and a literature search conducted for each drug's pharmacokinetic properties, concentrating on the volume of distribution (Vd). Hydrophobic drugs have a higher Vd than hydrophilic drugs as they distribute preferentially to fat mass (FM). The larger the Vd, the higher the initial dose required to achieve therapeutic plasma concentrations. Actual body weight (ABW) estimates are a good indicator of Vd for hydrophobic drugs as they correlate well with FM. Ideal body weight (IBW) estimates may be a better indicator of Vd for hydrophilic drugs, as they correlate better with lean body mass. This highlights potential variation between ABW and IBW, which may result in toxic or sub-therapeutic dosing.

RESULTS

The new APLS formulae give higher estimates of expected weight for a wider age range. This may be a more accurate reflection of ABW due to increasing prevalence of obesity in children. The UK Resuscitation Council's formula appears to result in a lower estimate of weight, which may relate more closely to IBW.

CONCLUSION

The main drugs used in paediatric resuscitation are hydrophilic, thus the APLS formulae may result in too much being given. Therefore the UK Resuscitation Council's single formula may be preferred. In addition, a single formula may minimize error in the context of a child of unknown weight requiring administration of emergency resuscitation drugs.

Antecedents of inflammation biomarkers in preterm newborns on days 21 and 28

AIM

Most studies of systemic inflammation in very preterm newborns focus on assessments made during the first two weeks. The purpose of this study was to identify some of the antecedents of systemic inflammation evident during postnatal weeks three and four.

METHODS

We measured the protein concentrations in blood spots collected on postnatal days 21 (N = 176) and 28 (N = 157) from infants born before the 28th week of gestation and sought correlates of measurements in the top quartile. Odds ratios of elevated concentrations were calculated for the most obvious correlates.

RESULTS

Infants born for maternal and foetal indications were more likely than their peers to have top quartile concentrations of IL-beta, IL-8, TNF-alpha and ICAM-1 on both days 21 and 28. Similarly, infants whose birthweight Z-score was <-2 or between -1 and -2 were also more likely than their peers to have elevated concentrations of these proteins.

CONCLUSION

Markers of systemic inflammation in the very preterm newborn during the third and fourth postnatal weeks are most strongly associated with maternal and foetal indications for (very preterm) delivery and their common correlate/consequence, foetal growth restriction.

Perioperative treatment of hemophilia A patients: blood group O patients are at risk of bleeding complications

ESSENTIALS: Targeting of factor VIII values is a challenge during perioperative replacement therapy in hemophilia. This study aims to identify the extent and predictors of factor VIII underdosing and overdosing. Blood group O predicts underdosing and is associated with perioperative bleeding. To increase quality of care and cost-effectiveness of treatment, refining of dosing is obligatory.

SUMMARY

BACKGROUND

Perioperative administration of factor VIII (FVIII) concentrate in hemophilia A may result in both underdosing and overdosing, leading to respectively a risk of bleeding complications and unnecessary costs.

OBJECTIVES

This retrospective observational study aims to identify the extent and predictors of underdosing and overdosing in perioperative hemophilia A patients (FVIII levels < 0.05 IU mL(-1)).

PATIENTS AND METHODS

One hundred nineteen patients undergoing 198 elective, minor, or major surgical procedures were included (median age 40 years, median body weight 75 kg). Perioperative management was evaluated by quantification of perioperative infusion of FVIII concentrate and achieved FVIII levels. Predictors of underdosing and (excessive) overdosing were analyzed by logistic regression analysis. Excessive overdosing was defined as upper target level plus ≥ 0.20 IU mL(-1).

RESULTS

Depending on postoperative day, 7-45% of achieved FVIII levels were under and 33-75% were above predefined target ranges as stated by national guidelines. A potential reduction of FVIII consumption of 44% would have been attained if FVIII levels had been maintained within target ranges. Blood group O and major surgery were predictive of underdosing (odds ratio [OR] 6.3, 95% confidence interval [CI] 2.7-14.9; OR 3.3, 95% CI 1.4-7.9). Blood group O patients had more bleeding complications in comparison to patients with blood group non-O (OR 2.02, 95% CI 1.00-4.09). Patients with blood group non-O were at higher risk of overdosing (OR 1.5, 95% CI 1.1-1.9). Additionally, patients treated with bolus infusions were at higher risk of excessive overdosing (OR 1.8, 95% CI 1.3-2.4).

CONCLUSION

Quality of care and cost-effectiveness can be improved by refining of dosing strategies based on individual patient characteristics such as blood group and mode of infusion.

Adverse reactions following routine anticholinergic eye drops in a paediatric population: an observational cohort study

OBJECTIVES

To investigate the presence, nature and relationship to age, sex, ethnicity and body mass index (BMI) of adverse reactions following routine cycloplegic eye drops in children.

DESIGN

Prospective observational cohort study.

SETTING

Ophthalmology outpatient clinic Dutch metropolitan hospital; February, March and April 2009.

PARTICIPANTS

Children aged 3-14-year-old children receiving two drops of cyclopentolate 1% (C+C) or one drop of cyclopentolate 1% and one drop of tropicamide 1% (C+T). Patients were categorised by age (3-6, 7-10 and 11-14 years), sex, ethnicity and body mass index (BMI) (low, normal or high).

OUTCOME MEASURES

Rate and nature of adverse reactions reported at 45 min following treatment. Crude and adjusted ORs for reporting an adverse reaction using stepwise regression analysis with BMI, age, ethnicity and sex.

RESULTS

912 of 915 eligible patients participated (99.7%). Adverse reactions were reported for C+C in 10.3% and in C+T in 4.8% (42/408 and 24/504, p=0.002), respectively. Central effects were present in 95% in C+C and in 92% in C+T. Compared to C+T, an increased risk was present in C+C (crude OR 2.3 (1.4 to 3.9), p=0.002). Forward adjustment showed BMI to be an influencing factor in treatment (OR 3.1 (1.7 to 5.6), p<0.001). In a multivariate model, a dose of cyclopentolate remained associated with adverse reactions. Analysis per BMI and regime and age category and regime, indicated associations with low BMI (OR C+C 21.4 (6.7 to 67.96), p<0.001, respectively, C+T 5.2 (2.1 to 12.8), p<0.001) and young age (OR C+C 8.1 (2.7 to 24.8), p<0.001).

CONCLUSIONS

Adverse reactions were common and almost exclusively involved the central nervous system. Both presence and severity were associated with repeated instillation of cyclopentolate 1%, low BMI and young age. In specific paediatric populations, a single dose of cyclopentolate must be considered. Vital function monitoring facilities are advisable. Adjustment of guidelines is recommended.

Renal Function Descriptors in Neonates: Which Creatinine-Based Formula Best Describes Vancomycin Clearance?

Growth and maturational changes have been identified as significant covariates in describing variability in clearance of renally excreted drugs such as vancomycin. Because of immaturity of clearance mechanisms, quantification of renal function in neonates is of importance. Several serum creatinine (SCr)-based renal function descriptors have been developed in adults and children, but none are selectively derived for neonates. This review summarizes development of the neonatal kidney and discusses assessment of the renal function regarding estimation of glomerular filtration rate using renal function descriptors. Furthermore, identification of the renal function descriptors that best describe the variability of vancomycin clearance was performed in a sample study of a septic neonatal cohort. Population pharmacokinetic models were developed applying a combination of age-weight, renal function descriptors, or SCr alone. In addition to age and weight, SCr or renal function descriptors significantly reduced variability of vancomycin clearance. The population pharmacokinetic models with Léger and modified Schwartz formulas were selected as the optimal final models, although the other renal function descriptors and SCr provided reasonably good fit to the data, suggesting further evaluation of the final models using external data sets and cross validation. The present study supports incorporation of renal function descriptors in the estimation of vancomycin clearance in neonates.

Effect of Kidney Function on Drug Kinetics and Dosing in Neonates, Infants, and Children

Neonates, infants, and children differ from adults in many aspects, not just in age, weight, and body composition. Growth, maturation and environmental factors affect drug kinetics, response and dosing in pediatric patients. Almost 80% of drugs have not been studied in children, and dosing of these drugs is derived from adult doses by adjusting for body weight/size. As developmental and maturational changes are complex processes, such simplified methods may result in subtherapeutic effects or adverse events. Kidney function is impaired during the first 2 years of life as a result of normal growth and development. Reduced kidney function during childhood has an impact not only on renal clearance but also on absorption, distribution, metabolism and nonrenal clearance of drugs. 'Omics'-based technologies, such as proteomics and metabolomics, can be leveraged to uncover novel markers for kidney function during normal development, acute kidney injury, and chronic diseases. Pharmacometric modeling and simulation can be applied to simplify the design of pediatric investigations, characterize the effects of kidney function on drug exposure and response, and fine-tune dosing in pediatric patients, especially in those with impaired kidney function. One case study of amikacin dosing in neonates with reduced kidney function is presented. Collaborative efforts between clinicians and scientists in academia, industry, and regulatory agencies are required to evaluate new renal biomarkers, collect and share prospective pharmacokinetic, genetic and clinical data, build integrated pharmacometric models for key drugs, optimize and standardize dosing strategies, develop bedside decision tools, and enhance labels of drugs utilized in neonates, infants, and children.

Early Gelatinase Activity Is Not a Determinant of Long-Term Recovery after Traumatic Brain Injury in the Immature Mouse

The gelatinases, matrix metalloproteinases (MMP)-2 and MMP-9, are thought to be key mediators of secondary damage in adult animal models of brain injury. Moreover, an acute increase in these proteases in plasma and brain extracellular fluid of adult patients with moderate-to-severe traumatic brain injuries (TBIs) is associated with poorer clinical outcomes and mortality. Nonetheless, their involvement after TBI in the pediatric brain remains understudied. Using a murine model of TBI at postnatal day 21 (p21), approximating a toddler-aged child, we saw upregulation of active and pro-MMP-9 and MMP-2 by gelatin zymography at 48 h post-injury. We therefore investigated the role of gelatinases on long-term structural and behavioral outcomes after injury after acute inhibition with a selective gelatinase inhibitor, p-OH SB-3CT. After systemic administration, p-OH SB-3CT crossed the blood-brain barrier at therapeutically-relevant concentrations. TBI at p21 induced hyperactivity, deficits in spatial learning and memory, and reduced sociability when mice were assessed at adulthood, alongside pronounced tissue loss in key neuroanatomical regions. Acute and short-term post-injury treatment with p-OH SB-3CT did not ameliorate these long-term behavioral, cognitive, or neuropathological deficits as compared to vehicle-treated controls, suggesting that these deficits were independent of MMP-9 and MMP-2 upregulation. These findings emphasize the vulnerability of the immature brain to the consequences of traumatic injuries. However, early upregulation of gelatinases do not appear to be key determinants of long-term recovery after an early-life injury.

Determination of the impurities in drug products containing montelukast and in silico/in vitro genotoxicological assessments of sulfoxide impurity

Impurities affecting safety, efficacy, and quality of pharmaceuticals are of increasing concern for regulatory agencies and pharmaceutical industries, since genotoxic impurities are understood to play important role in carcinogenesis. The study aimed to analyse impurities of montelukast chronically used in asthma theraphy and perform genotoxicological assessment considering regulatory approaches. Impurities (sulfoxide, cis-isomer, Michael adducts-I&II, methylketone, methylstyrene) were quantified using RP-HPLC analysis on commercial products available in Turkish market. For sulfoxide impurity, having no toxicity data and found to be above the qualification limit, in silico mutagenicity prediction analysis, miniaturized bacterial gene mutation test, mitotic index determination and in vitro chromosomal aberration test w/wo metabolic activation system were conducted. In the analysis of different batches of 20 commercial drug products from 11 companies, only sulfoxide impurity exceeded qualification limit in pediatric tablets from 2 companies and in adult tablets from 7 companies. Leadscope and ToxTree programs predicted sulfoxide impurity as nonmutagenic. It was also found to be nonmutagenic in Ames MPF Penta I assay. Sulfoxide impurity was dose-dependent cytotoxic in human peripheral lymphocytes, however, it was found to be nongenotoxic. It was concluded that sulfoxide impurity should be considered as nonmutagenic and can be classified as ordinary impurity according to guidelines.

Pediatric drug formulations: a review of challenges and progress

Children differ from adults in many aspects of pharmacotherapy, including capabilities for drug administration, medicine-related toxicity, and taste preferences. It is essential that pediatric medicines are formulated to best suit a child's age, size, physiologic condition, and treatment requirements. To ensure adequate treatment of all children, different routes of administration, dosage forms, and strengths may be required. Many existing formulations are not suitable for children, which often leads to off-label and unlicensed use of adult medicines. New regulations, additional funding opportunities, and innovative collaborative research initiatives have resulted in some recent progress in the development of pediatric formulations. These advances include a paradigm shift toward oral solid formulations and a focus on novel preparations, including flexible, dispersible, and multiparticulate oral solid dosage forms. Such developments have enabled greater dose flexibility, easier administration, and better acceptance of drug formulations in children. However, new pediatric formulations address only a small part of all therapeutic needs in children; moreover, they are not always available. Five key issues need to be addressed to stimulate the further development of better medicines for children: (1) the continued prioritization of unmet formulation needs, particularly drug delivery in neonates and treatment gaps in pediatric cancers and childhood diseases in developing countries; (2) a better use of existing data to facilitate pediatric formulation development; (3) innovative technologies in adults that can be used to develop new pediatric formulations; (4) clinical feedback and practice-based evidence on the impact of novel formulations; and (5) improved access to new pediatric formulations.