Study Population

Use of physiologically-based pharmacokinetic modeling to inform dosing of the opioid analgesics fentanyl and methadone in children with obesity

Posted on by Kayla Korzekwinski

CPT: Pharmacometrics & Systems Pharmacology • June 2022

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Gerhart JG, Carreno FO, Ford JL, Edginton AN, Perrin EM, Watt KM, Muller WJ, Atz AM, Al-Uzri A, Delmore P, Gonzalez D; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
Children with obesity are commonly prescribed the opioids fentanyl and methadone, and accurate dosing is critical to reducing the risk of serious adverse events associated with overexposure. However, there is limited information to guide fentanyl and methadone dosing in these children. This study addresses the clinical knowledge gap using physiologically-based pharmacokinetic models of fentanyl and methadone developed in adults and scaled to children with and without obesity to explore the interplay of obesity, age, and pharmacogenomics.

External Evaluation of Risperidone Population Pharmacokinetic Models Using Opportunistic Pediatric Data

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Frontiers in Pharmacology • March 2022

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Karatza E, Ganguly S, Hornik CD, Muller MJ, Al-Uzri A, James L, Balevic SJ, Gonzalez D; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
Risperidone is approved to treat schizophrenia in adolescents and autistic disorder and bipolar mania in children and adolescents. It is also used off-label in younger children for various psychiatric disorders. The objectives of this study were to assess whether opportunistically collected pediatric data can be used to evaluate risperidone population pharmacokinetic models externally and to identify a robust model for precision dosing in children. All the models had a modest predictive performance, potentially suggesting that sources of inter-individual variability were not entirely captured and that opportunistic data from a highly heterogeneous population are likely not the most appropriate data to evaluate risperidone models externally.

Development and Evaluation of a Virtual Population of Children with Obesity for Physiologically Based Pharmacokinetic Modeling

Posted on by Kayla Korzekwinski

Clinical Pharmacokinetics • February 2022

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Gerhart JG, Carreno FO, Edginton AN, Sinha J, Perrin E, Kumar KR, Rikhi A, Hornik CP, Harris V, Ganguly S, Cohen-Wolkowiez M, Gonzalez D; on behalf of the Best Pharmaceuticals for Children Act — Pediatric Trials Network Steering Committee
A virtual population of children with obesity was developed using national survey, electronic health record, and clinical trial data, as well as data extracted from the literature. The objective of this study was to develop a virtual population of children with obesity to enable physiologically based pharmacokinetic modeling, then use the novel virtual population in conjunction with previously developed models of clindamycin and trimethoprim/sulfamethoxazole to better understand dosing of these drugs in children with obesity. Model simulations supported current recommended weight-based dosing in children with obesity for clindamycin and trimethoprim/sulfamethoxazole, as they met target exposure despite these changes in clearance and volume of distribution.

Impact of Personal Protective Equipment on the Performance of Emergency Pediatric Tasks

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Pediatric Emergency Care • December 2021

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Adler MD, Krug S, Eiger C, Good GL, Kou M, Nash M, Henretig FM, Hornik CP, Gosnell L, Chen JY, Debski J, Sharma G, Siegel D, Donoghue A
This study evaluated the impacts of personal protective equipment (PPE) on timeliness or success of emergency procedures performed by pediatric health care providers (HCPs). For session 1, HCPs wore normal attire; for session 2, they wore full-shroud PPE garb with 2 glove types: Ebola level or chemical. During each session, they performed clinical tasks on a patient simulator: intubation, bag-valve mask ventilation, venous catheter (IV) placement, push-pull fluid bolus, and defibrillation. Personal protective equipment did not affect procedure timeliness or success on a simulated child, with the exception of IV placement. Further study is needed to investigate PPE’s impact on procedures performed in a clinical care context.

Safety of sildenafil in extremely premature infants: a phase I trial

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Journal of Perinatology • January 2022

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Jackson W, Gonzalez D, Smith PB, Ambalavanan N, Atz A, Sokol GM, Hornik CD, Stewart D, Mundakel G, Poindexter BB, Ahlfeld SK, Mills M, Cohen-Wolkowiez M, Martz K, Hornik CP, Laughon MM; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
This study sought to characterize the safety of sildenafil in premature infants. Safety was evaluated based on adverse events (AEs), transaminase levels, and mean arterial pressure monitoring. There was one serious AE related to the study drug involving hypotension associated with a faster infusion rate than specified by the protocol. There were no AEs related to elevated transaminases. Sildenafil was well tolerated by the study population. Drug administration times and flush rates require careful attention to prevent infusion-related hypotension associated with faster infusions of IV sildenafil in premature infants.

External Evaluation of Two Pediatric Population Pharmacokinetics Models of Oral Trimethoprim and Sulfamethoxazole

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Antimicrobial Agents and Chemotherapy • June 2021

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Wu YSS, Cohen-Wolkowiez M, Hornik CP, Gerhart JG, Autmizguine J, Cobbaert M, Gonzalez D
This study tested the pediatric pharmacokinetics (PK) of the antibiotic combination trimethoprim (TMP)-sulfamethoxazole (SMX) that is used to treat a variety of infections. Both models used supported TMP-SMX dose increases in infants and young children for resistant pathogens with a MIC of 1 mg/liter, although the required dose increase based on the external model was lower.

Prolonged Post-Discontinuation Antibiotic Exposure in Very Low Birth Weight Neonates at Risk for Early-Onset Sepsis

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Journal of the Pediatric Infectious Diseases Society • May 2021

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Le J, Greenberg RG, Benjamin DK Jr, Yoo Y, Zimmerman KO, Cohen-Wolkowiez M, Wade KC; on behalf of the Administrative Core Committee of the Best Pharmaceuticals for Children Act – Pediatric Trials Network
Premature, very low birth weight neonates are at risk for early-onset sepsis and receive ampicillin and gentamicin post-birth. Antimicrobial stewardship supports short-course antibiotics, but how long antibiotic concentrations remain therapeutic post-last dose is unknown. This study used simulations to examine antibiotic exposures in 34,689 neonates. Therapeutic exposure for ampicillin and gentamicin was evaluated relative to the minimum inhibitory concentration for common pathogens. Ampicillin exposure remains therapeutic long after the last dose. Short-course ampicillin provided therapeutic exposures throughout the typical blood culture incubation period.

Evaluating Site-Level Implementations of the HL7 FHIR Standard to Support eSource Data Exchange in Clinical Research

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Studies in Health Technology and Informatics • May 2021

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Garza MY, Eisenstein E, Kumar KR, Zimmerman KO, Zozus M
Direct extraction and use of electronic health record (EHR) data is a long-term and multifaceted endeavor. A systematic mapping of study data elements was used to measure the coverage of the Health Level Seven (HL7®) Fast Healthcare Interoperability Resources (FHIR®) standard for a federally sponsored, pragmatic cardiovascular randomized controlled trial (RCT) targeting adults. Researchers evaluated site-level implementations of the HL7® FHIR® standard to investigate study- and site-level differences that could affect coverage and offer insight into the feasibility of a FHIR-based eSource solution for multicenter clinical research.

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

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Pediatrics • May 2021

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Abdel-Rahman SM, Paul IM, Hornik C, Sullivan JE, Wade K, Delmore P, Sharma G, Benjamin DK, Zimmerman KO

The Best Pharmaceuticals for Children Act (BPCA) incentivizes the study of on-patent medicines in children and mandates that the NIH 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. This investigation evaluates racial and ethnic minority representation among participants enrolled in BPCA-sponsored studies. 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.

Estimation of Body Fat Percentage for Clinical Pharmacokinetic Studies in Children

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Clinical and Translational Science • March 2021

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Green TP, Binns HJ, Wu H, Ariza AJ, Perrin EM, Quadri M, Hornik CP, Cohen-Wolkowiez M

Obesity is a prevalent childhood condition and the degree of adiposity is likely to be an important covariate in the pharmacokinetics (PKs) of many drugs. The goal of these studies was to facilitate the evaluation and, where appropriate, quantification of the covariate effect of body fat percentage (BF%) on PK parameters in children. Researchers examined two large databases to determine the values and variabilities of BF% in children with healthy body weights and in those with obesity, comparing the accuracy and precision of BF% estimation by both clinical methods and demographically derived techniques. They also conducted simulation studies to evaluate the utility of the several methods for application in clinical trials. The estimation of BF% from sex and obesity stage can routinely be applied to PK clinical trials to evaluate the contribution of BF% as a potential covariate.