A Pilot Study of Ketotifen in Patients Aged 8-17 Years with Functional Dyspepsia Associated with Mucosal Eosinophilia.

BACKGROUND AND OBJECTIVE: Mast cells have been implicated in abdominal pain-associated disorders of gut-brain interaction, such as functional dyspepsia. As such, ketotifen, a second-generation antihistamine and mast cell stabilizer, could represent a viable treatment option in these conditions. The primary aim of the current pilot study was to assess clinical response to ketotifen and assess pharmacokinetics in youth with functional dyspepsia. METHODS: We conducted a pilot randomized, double-blind, placebo-controlled, cross-over trial of ketotifen in 11 youth with functional dyspepsia and duodenal mucosal eosinophilia with 4 weeks of active treatment at a dose of 1 mg twice daily. Global clinical response was graded on a 5-point Likert Scale. A single plasma sample was obtained at steady state for pharmacokinetic analysis. RESULTS: Ketotifen was not superior to placebo with regard to global clinical response. Only 18% of patients demonstrated a complete or near-complete clinical response. The estimated half-life was 3.3 h. CONCLUSIONS: While ketotifen was not superior to placebo, this study highlights several important challenges for developing drug trials for youth with chronic abdominal pain. Recommendations are made for designing a larger treatment trial for ketotifen in this patient group. CLINICAL TRIAL REGISTRATION: This study was registered at ClinicalTrials.gov: NCT02484248.

Influence of novel CYP2C-haplotype on proton pump inhibitor pharmacokinetics in children.

In this brief report, we provide an analysis of the influence of a novel CYP2C haplotype (CYP2C:TG) on proton pump inhibitor (PPI) pharmacokinetics (PK) in children. The CYP2C:TG haplotype has been proposed to be associated with increased CYP2C19 activity. We sought to determine if this CYP2C:TG haplotype resulted in similar alterations in metabolism for proton pump inhibitors, which are primarily metabolized by CYP2C19. In a cohort of 41 children aged 6-21 participating in a PPI pharmacokinetic study, effects of the CYP2C:TG allele were assessed by fitting two linear regression models for each of the six PK outcomes assessed, the second of which accounted for the presence of the CYP2C:TG allele. The difference in R2 values between the two models was computed to quantify the variability in the outcome that could be accounted for by the CYP2C:TG allele after adjustment for the CYP2C19 genotype. We found the CYP2C:TG haplotype to have no measurable additive impact on CYP2C19-mediated metabolism of PPIs in vivo in older children and adolescents. The findings of this study do not support the clinical utility of routine testing for the CYP2C:TG haplotype to guide PPI dose adjustments in children.

SLCO1B1 Genetic Variation Influence on Atorvastatin Systemic Exposure in Pediatric Hypercholesterolemia.

This clinical study examined the influence of SLCO1B1 c.521T>C (rs4149056) on plasma atorvastatin concentrations in pediatric hypercholesterolemia. The participants (8-21 years), including heterozygous (c.521T/C, n = 13), homozygous (c.521C/C, n = 2) and controls (c.521T/T, n = 13), completed a single-oral-dose pharmacokinetic study. Similar to in adults, the atorvastatin (AVA) area-under-concentration-time curve from 0 to 24 h (AUC0-24) was 1.7-fold and 2.8-fold higher in participants with c.521T/C and c.521C/C compared to the c.521T/T participants, respectively. The inter-individual variability in AVA exposure within these genotype groups ranged from 2.3 to 4.8-fold, indicating that additional factors contribute to the inter-individual variability in the AVA dose-exposure relationship. A multivariate model reinforced the SLCO1B1 c.521T>C variant as the central factor contributing to AVA systemic exposure in this pediatric cohort, accounting for ~65% of the variability in AVA AUC0-24. Furthermore, lower AVA lactone concentrations in participants with increased body mass index contributed to higher exposure within the c.521T/T and c.521T/C genotype groups. Collectively, these factors contributing to higher systemic exposure could increase the risk of toxicity and should be accounted for when individualizing the dosing of atorvastatin in eligible pediatric patients.

Potential biomarker of brain response to opioid antagonism in adolescents with eating disorders: a pilot study.

Background: Eating Disorders (ED) affect up to 5% of youth and are associated with reward system alterations and compulsive behaviors. Naltrexone, an opioid antagonist, is used to treat ED behaviors such as binge eating and/or purging. The presumed mechanism of action is blockade of reward activation; however, not all patients respond, and the optimal dose is unknown. Developing a tool to detect objective drug response in the brain will facilitate drug development and therapeutic optimization. This pilot study evaluated neuroimaging as a pharmacodynamic biomarker of opioid antagonism in adolescents with ED. Methods: Youth aged 13-21 with binge/purge ED completed functional magnetic resonance imaging (fMRI) pre- and post-oral naltrexone. fMRI detected blood oxygenation-level dependent (BOLD) signal at rest and during two reward probes (monetary incentive delay, MID, and passive food view, PFV) in predefined regions of interest associated with reward and inhibitory control. Effect sizes for Δ%BOLD (post-naltrexone vs. baseline) were estimated using linear mixed effects modeling. Results: In 12 youth (16-21 years, 92% female), BOLD signal changes were detected following naltrexone in the nucleus accumbens during PFV (Δ%BOLD -0.08 ± 0.03; Cohen's d -1.06, p = 0.048) and anterior cingulate cortex during MID (Δ%BOLD 0.06 ± 0.03; Cohen's d 1.25, p = 0.086). Conclusion: fMRI detected acute reward pathway modulation in this small sample of adolescents with binge/purge ED. If validated in future, larger trials, task-based Δ%BOLD detected by fMRI may serve as a pharmacodynamic biomarker of opioid antagonism to facilitate the development of novel therapeutics targeting the reward pathway, enable quantitative pharmacology trials, and inform drug dosing. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT04935931, NCT#04935931.

Effects of genotype and food on naltrexone exposure in adolescents.

Naltrexone (NTX), an opioid antagonist metabolized by aldo-keto reductase 1C4 (AKR1C4), is prescribed for psychiatric conditions like eating disorders with variable response. Systemic exposure is highly variable in adults, yet no data exist in children. The purpose of this study was to evaluate NTX exposure in adolescents with eating disorders. Adolescents aged 12-21 years with eating disorders underwent postdose blood sampling in the fasted and/or fed state. NTX and primary active metabolite, 6-ß-naltrexol, were determined by ultra-high performance liquid chromatography tandem mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental analysis. DNA was genotyped for AKR1C4 missense mutations associated with decreased activity (rs3829125 and rs17134592). Linear mixed effects modeling was performed. In 21 participants, aged 16.9 ± 1.9 years (15-21 years), 81% female participants, maximum concentration (Cmax ) was 90.4 ± 129 nM/mg/kg, area under the concentration-time curve from zero to infinity (AUC0-∞ ) was 166 ± 154 nM h/mg/kg, and varied 63-fold and 21-fold, respectively. Compared with wildtype, those with AKR1C4 allelic variations (n = 7) displayed 3.2-fold higher AUC0-∞ , four-fold higher Cmax and delayed time to Tmax . Linear mixed effects modeling demonstrated a large effect of genotype on AUC0-∞ (Cohen's d -2.3) and Cmax (Cohen's d -1.4). Food effect was large for AUC0-∞ (Cohen's d 2.6), but highly variable and failed to reach significance for Cmax. The respective model accounted for 82% of the variance in NTX AUC0-∞ and 46% of the variance in Cmax . NTX systemic exposure is highly variable in adolescents with eating disorders and modulated, in part, by AKR1C4 genotype and food intake. These findings may, in part, explain the large degree of interindividual variability observed response to NTX.

Parental understanding and attitudes following pharmacogenomic testing for pediatric neuropsychiatric patients.

Aim: This study explores parental understanding and attitudes around pharmacogenomic results in their child(ren). Patients and methods: In-depth interviews with parents whose child(ren) had received a pharmacogenomic testing panel for management of neuropsychiatric medications were completed. Interviews were analyzed for themes and accuracy of understanding of results. Results: In 18 parents interviewed, 49/63 (78%) of statements made regarding results were accurate. Differences in understanding were seen by clinic, number of medications and result type. Parents expected results to guide prescribing and perceived the greatest utility in results that could impact current care. Results predicting normal drug metabolism may create mixed feelings. Conclusion: Parents perceive utility in pharmacogenomic testing for their children. Challenges exist in understanding probabilistic and multifactorial information about pharmacogenomic results.

Peppermint oil effects on the gut microbiome in children with functional abdominal pain.

Peppermint oil (PMO) is effective in the treatment of functional abdominal pain disorders, but its mechanism of action is unclear. Evidence suggests PMO has microbicidal activity. We investigated the effect of three different doses of PMO on gut microbiome composition. Thirty children (7-12 years of age) with functional abdominal pain provided a baseline stool sample prior to randomization to 180, 360, or 540 mg of enteric coated PMO (10 participants per dose). They took their respective dose of PMO (180 mg once, 180 mg twice, or 180 mg thrice daily) for 1 week, after which the stool collection was repeated. Baseline and post-PMO stools were analyzed for microbiome composition. There was no difference in alpha diversity of the gut microbiome between the baseline and post-PMO treatment. Principal coordinate analysis revealed no significant difference in overall bacterial composition between baseline and post-PMO samples, as well as between the PMO dose groups. However, the very low abundant Collinsella genus and three operational taxonomic units (one belonging to Collinsella) were significantly different in samples before and after PMO treatment. The Firmicutes/Bacteroidetes ratio was lower in children who received 540 mg of PMO compared to the 180 mg and 360 mg dose groups (p = 0.04). Network analysis revealed separation between pre- and post-PMO fecal samples with the genus Collinsella driving the post-PMO clusters. PMO administration appeared to impact only low abundance bacteria. The 540 mg PMO dose differentially impacted the Firmicutes/Bacteroidetes ratio. A higher dose and/or longer duration of treatment might yield different results.

Utility of the 13 C-pantoprazole breath test as a CYP2C19 phenotyping probe for children.

The 13 C-pantoprazole breath test (PAN-BT) is a safe, noninvasive, in vivo CYP2C19 phenotyping probe for adults. Our objective was to evaluate PAN-BT performance in children, with a focus on discriminating individuals who, according to guidelines from the Clinical Pharmacology Implementation Consortium (CPIC), would benefit from starting dose escalation versus reduction for proton pump inhibitors (PPIs). Children (n = 65, 6-17 years) genotyped for CYP2C19 variants *2, *3, *4, and *17 received a single oral dose of 13 C-pantoprazole. Plasma concentrations of pantoprazole and its metabolites, and changes in exhaled 13 CO2 (termed delta-over-baseline or DOB), were measured 10 times over 8 h using high performance liquid chromatography with ultraviolet detection and spectrophotometry, respectively. Pharmacokinetic parameters of interest were generated and DOB features derived using feature engineering for the first 180 min postadministration. DOB features, age, sex, and obesity status were used to run bootstrap analysis at each timepoint (Ti ) independently. For each iteration, stratified samples were drawn based on genotype prevalence in the original cohort. A random forest was trained, and predictive performance of PAN-BT was evaluated. Strong discriminating ability for CYP2C19 intermediate versus normal/rapid metabolizer phenotype was noted at DOBT30 min (mean sensitivity: 0.522, specificity: 0.784), with consistent model outperformance over a random or a stratified classifier approach at each timepoint (p < 0.001). With additional refinement and investigation, the test could become a useful and convenient dosing tool in clinic to help identify children who would benefit most from PPI dose escalation versus dose reduction, in accordance with CPIC guidelines.

Randomised trial: Peppermint oil (menthol) pharmacokinetics in children and effects on gut motility in children with functional abdominal pain.

AIMS: Little is known regarding the pharmacokinetics and pharmacodynamics of menthol, the active ingredient in peppermint oil (PMO). Our aim was to investigate the pharmacokinetics of menthol at 3 dose levels in children and determine their effects on gut motility and transit. METHODS: Thirty children ages 7-12 years with functional abdominal pain underwent wireless motility capsule (WMC) testing. Approximately 1 week later they were randomized to 180, 360 or 540 mg of enteric coated PMO (10 participants per dose). Menthol pharmacokinetics were determined via blood sampling over 24 hours. They then took their respective dose of PMO (180 mg once, 180 mg twice or 180 mg thrice daily) for 1 week during which time the WMC test was repeated. RESULTS: Evaluable area under the plasma concentration vs. time curve (AUClast ) data were available in 29 of 30 participants. A direct linear relationship (apparent dose-proportionality for systemic menthol exposure) was observed between PMO dose and menthol systemic exposure with mean elimination half-life 2.1, 3.5 and 4.6 hours for the 180, 360 and 540 mg doses, respectively. WMC technical issues precluded complete motility data in all participants. Colonic transit time was inversely related to AUClast (P = .003); transit time in other regions was not affected. In contrast, stomach, small bowel and whole gut (but not colonic) contractility positively correlated with menthol AUClast (P < .05). CONCLUSION: Pharmacokinetics and pharmacodynamics of menthol derived from PMO demonstrated apparent dose-proportionality. A higher dose of PMO may be needed to achieve maximal gut response. www.clinicaltrials.gov NCT03295747.

Developmental Considerations for the Use of Naltrexone in Children and Adolescents.

Naltrexone (NTX) is a well-tolerated drug with a wide safety margin and mechanism of action that affords use across a wide variety of indications in adults and children. By antagonizing the opioid reward system, NTX can modulate behaviors that involve compulsivity or impulsivity, such as substance use, obesity, and eating disorders. Evidence regarding the disposition and efficacy of NTX is mainly derived from adult studies of substance use disorders and considerable variability exists. Developmental changes, plausible disease-specific alterations and genetic polymorphisms in NTX disposition, and pharmacodynamic pathways should be taken into consideration when optimizing the use of NTX in the pediatric population. This review highlights the current state of the evidence and gaps in knowledge regarding NTX to facilitate evidence-based pharmacotherapy of mental health conditions, for which few pharmacologic options exist.

Profiling Pretomanid as a Therapeutic Option for TB Infection: Evidence to Date.

Tuberculosis (TB) is the most deadly infectious disease globally. Although most individuals achieve a cure, a substantial portion develop multi-drug resistant TB which is exceedingly difficult to treat, and the number of effective agents is dwindling. Development of new anti-tubercular medications is imperative to combat existing drug resistance and accelerate global eradication of TB. Pretomanid (PA-824) represents one of the newest drug classes (ie, nitroimidazooxazines) approved in 2019 by the United States Food and Drug Administration as part of a multi-drug regimen (with bedaquiline and linezolid, BPaL) and recommended by the World Health Organization (WHO) to treat extensively-resistant (XR-TB) and multi-drug resistant tuberculosis (MDR-TB). Approval was granted through the FDA's Limited Population Pathway for Antibacterial and Antifungal Drugs, which accelerates approval for antimicrobial drugs used to treat life-threatening or serious infections in a limited population with unmet need. This review details the pharmacology, efficacy, and safety of this new agent and describes evidence to date for its role in the treatment of drug resistant TB including published, ongoing, and planned studies.

A call to action: Issuing a diversity and inclusion challenge to research organizations.

Individuals who identify as Black, indigenous, and people of color face well-documented health disparities. A root cause is the lack of empiric evidence for or against the use of various treatments in their medical management. This communication proposes a new benchmarking strategy for evaluating racial and ethnic representation in clinical research that can be compared across institutions with the intent of increasing accountability for diversity and inclusion among organizations that conduct clinical research.

Adolescent perceptions of pharmacogenetic testing.

Background: Despite the expansion of pharmacogenetics (PGx), the views of pediatric patients remain unknown. This study explores adolescents' understanding and perceptions of PGx testing. Methods: Adolescents who had PGx testing were interviewed and their electronic health records were reviewed. Results: Adolescents accurately described reason for testing and most felt the results impacted their current and future care. None perceived risks to securing future employment or insurance. All felt PGx would benefit their peers. Conclusion: Adolescents understand the reasons for PGx and perceive testing to be useful, low risk and applicable to peers. Findings from this study advocate for the inclusion of adolescents in shared decision-making regarding testing and for active engagement in the discussion of results.

Racial and Ethnic Diversity in Studies Funded Under the Best Pharmaceuticals for Children Act.

BACKGROUND AND OBJECTIVES: The Best Pharmaceuticals for Children Act (BPCA) incentivizes the study of on-patent medicines in children and mandates that the National Institutes of Health sponsor research on off-patent drugs important to pediatric therapeutics. Failing to enroll cohorts that reflect the pediatric population at large restricts the generalizability of such studies. In this investigation, we evaluate racial and ethnic minority representation among participants enrolled in BPCA-sponsored studies. METHODS: Data were obtained for all participants enrolled in 33 federally funded studies of drugs and devices conducted from 2008 through June 2020. Observed racial and ethnic distributions were compared with expected distributions by sampling Census data at the same geographic frequency as in the studies. Racial and ethnic enrollment was examined by demography, geography, study type, study burden, and expected bias. Standard descriptive statistics, χ2, generalized linear models, and linear regression were applied. RESULTS: A total of 10 918 participants (51% male, 6.6 ± 8.2 years) were enrolled across 46 US states and 4 countries. Studies ranged from treatment outcome reviews to randomized, placebo-controlled trials. Minority enrollment was comparable to, or higher than, expected (+0.1% to +2.6%) for all groups except Asian Americans (-3.7%, P < .001). American Indian and Alaskan Native and multiracial enrollment significantly increased over the evaluation period (P < .01). There were no significant differences in racial distribution as a function of age or sex, although differences were observed on the basis of geography, study type, and study burden. CONCLUSIONS AND RELEVANCE: This study revealed no evidence of racial and ethnic bias in enrollment for pediatric studies conducted with funding from BPCA, fulfilling the legislation's expectation to ensure adequate representation of all children.

A Pilot Comparison of High- Versus Low-Tech Palatability Assessment Tools in Young Children.

BACKGROUND: Medication refusal in children is largely driven by aversive taste profiles, which in turn influence adherence and therapeutic outcomes. However, there are no standardized methods for evaluating taste in young children. This study compares facial recognition technology with three hedonic visual scales in this population. METHODS: Children, 3-7 years of age, were enrolled with informed parental permission into an institutional review board-approved, double-blind, randomized investigation. Each child received three test articles: prednisone (bitter), simple syrup (sweet), and filtered water (neutral), with an appropriate washout. Facial recognition software (Noldus FaceReader 7) recorded facial expression and intensity for 30-60 s after administration. Participants subsequently rated taste using three hedonic scales (5-point Sjövall and 5- and 3-point TASTY) and responded to simple questions on their perception of the test article. Repeated measures analysis of variance and multiple regression analysis were used to explore associations between palatability measures. RESULTS: Twelve children (seven males: ten white and two black) completed the study without adverse effects. There were no significant differences in participant characteristics by randomization sequence. The three hedonic scales tracked similarly for each test substance, with correlations between the 5-point scales (r = 0.899) comparable to those between the 3- and 5-point scales (r = 0.860-0.903). Hedonic scales appeared more reliable in assessing taste response than facial recognition, which did not effectively discriminate positive and negative responses. CONCLUSIONS: Our experience suggests that the TASTY scales appear to offer the greatest promise for assessing palatability in future clinical use.

Serum amoxicillin levels in young infants (0-59 days) with sepsis treated with oral amoxicillin.

BACKGROUND: WHO recommends simplified antibiotics for young infants with sepsis in countries where hospitalisation is not feasible. Amoxicillin provides safe, Gram-positive coverage. This study was done to determine pharmacokinetics, drug disposition and interpopulation variability of oral amoxicillin in this demographic. METHODS: Young infants with signs of sepsis enrolled in an oral amoxicillin/intramuscular gentamicin treatment arm of a sepsis trial in Karachi, Pakistan, were studied. Limited pharmacokinetic (PK) sampling was performed at 0, 2-3 and 6-8 hours following an index dose of oral amoxicillin. Plasma concentrations were determined by high-performance liquid chromatography/mass spectrometry. Values of ≥2 mg/L were considered as the effect threshold, given the regional minimal inhibitory concentration (MIC) of resistant Streptococcus pneumoniae. RESULTS: Amoxicillin concentrations were determined in 129 samples from 60 young infants. Six of 44 infants had positive blood cultures with predominant Gram-positive organisms. Forty-four infants contributing blood at ≥2 of 3 specified timepoints were included in the analysis. Mean amoxicillin levels at 2-3 hours (11.6±9.5 mg/L, n=44) and 6-8 hours (16.4±9.3 mg/L, n=20) following the index dose exceeded the MIC for amoxicillin (2.0 mg/L) against resistant S. pneumoniae strains. Of 20 infants with three serum levels, 7 showed a classic dose-exposure profile and 13 showed increasing concentrations with time, implying delayed absorption or excretion. CONCLUSION: Amoxicillin concentrations in sera of young infants following oral administration at 75-100 mg/kg/day daily divided doses exceeds the susceptibility breakpoint for >50% of a 12-hour dosing interval.Oral amoxicillin may hold potential as a safe replacement of parenteral ampicillin in newborn sepsis regimens, including aminoglycosides, where hospitalisation is not feasible. TRIAL REGISTRATION NUMBER: NCT01027429.

Design and Usability of an Electronic Health Record-Integrated, Point-of-Care, Clinical Decision Support Tool for Modeling and Simulation of Antihemophilic Factors.

BACKGROUND: With the consequences of inadequate dosing ranging from increased bleeding risk to excessive drug costs and undesirable administration regimens, the antihemophilic factors are uniquely suited to dose individualization. However, existing options for individualization are limited and exist outside the flow of care. We developed clinical decision support (CDS) software that is integrated with our electronic health record (EHR) and designed to streamline the process for our hematology providers. OBJECTIVES: The aim of this study is to develop and examine the usability of a CDS tool for antihemophilic factor dose individualization. METHODS: Our development strategy was based on the features associated with successful CDS tools and driven by a formal requirements analysis. The back-end code was based on algorithms developed for manual individualization and unit tested with 23,000 simulated patient profiles created from the range of patient-derived pharmacokinetic parameter estimates defined in children and adults. A 296-item heuristic checklist was used to guide design of the front-end user interface. Content experts and end-users were recruited to participate in traditional usability testing under an institutional review board approved protocol. RESULTS: CDS software was developed to systematically walk the point-of-care clinician through dose individualization after seamlessly importing the requisite patient data from the EHR. Classical and population pharmacokinetic approaches were incorporated with clearly displayed estimates of reliability and uncertainty. Users can perform simulations for prophylaxis and acute bleeds by providing two of four therapeutic targets. Testers were highly satisfied with our CDS and quickly became proficient with the tool. CONCLUSION: With early and broad stakeholder engagement, we developed a CDS tool for hematology provider that affords seamless transition from patient assessment, to pharmacokinetic modeling and simulation, and subsequent dose selection.

Examining a New Scale for Evaluating Taste in Children (TASTY).

OBJECTIVES: Pediatric medication taste impacts adherence, and current recommendations advocate for direct input from pediatric patients on medication taste during drug development. However, the lack of a widely used, validated measurement tool limits taste assessments. This protocol examines the validity of, and preferences for, a newly created self-report taste rating scale designed with images centered on taste (TASTY), compared with 2 existing hedonic taste scales. METHODS: This study was a prospective, single-center, randomized survey of child-parent dyads recruited from pediatric ambulatory care clinics and ancillary service waiting rooms. Parents facilitated the survey by identifying foods that they perceived their child would recall as pleasant, neutral, and unpleasant. Children were asked to rate each of the 3 food items on each of 3 different faces scales presented in random order. Parents and children were also asked which scale they preferred and why. RESULTS: Ninety child-parent dyads completed this study (mean child age was 6.7 ± 2.9 years, 58% female). All 3 scales performed comparably with no significant differences (p > 0.05). However, concordance between parental assignment and child rankings was markedly lower in 3-year-olds (r < 0.4) and 4-year-olds (r < 0.6) than for children 5 years and older (r > 0.9). TASTY was preferred by both parents and children when compared with the other scales. CONCLUSIONS: This novel hedonic taste scale for pediatric use is equally valid and preferred to comparable faces scales. The TASTY scale may be beneficial in developing standardized methodology for evaluating drug palatability.