Drug disposition

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

Posted on by Kayla Korzekwinski

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.

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.

Pharmacokinetics of Hydrochlorothiazide in Children: A Potential Surrogate for Renal Secretion Maturation

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The Journal of Clinical Pharmacology • March 2021

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Commander SJ, Wu H, Boakye-Agyeman F, Melloni C, Hornik CD, Zimmerman K, Al-Uzri A, Mendley SR, Harper B, Cohen-Wolkowiez M, Hornik CP
Hydrochlorothiazide (HCTZ) is a thiazide diuretic used in adults and children for the treatment of hypertension and edema. The pharmacokinetic (PK) properties of HCTZ in children are not well characterized, particularly among children with obesity who frequently suffer from hypertension and may, therefore, benefit from HCTZ therapy. Simulated exposure decreased with age and was likely due to older children receiving the maximum absolute doses of HCTZ. Further studies with more patients in each age group are required to confirm these PK findings of HCTZ in the children.

Population Pharmacokinetics of Olanzapine in Children

Posted on by Kayla Korzekwinski
British Journal of Clinical Pharmacology • February 2021
Maharaj AR, Wu H, Zimmerman KO, Autmizguine J, Kalra R, Al-Uzri A, Sherwin CMT, Goldstein SL, Watt K, Cohen-Wolkowiez M, Hornik CP; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
The aim of this study was to evaluate the population pharmacokinetics (PopPK) of olanzapine in children and devise a model-informed pediatric dosing scheme. This analysis is the first study to characterize the PK of olanzapine in participants ranging from infants to adolescents. Body weight and postmenstrual age (PMA) were identified as influential covariates for characterizing developmental changes in olanzapine apparent clearance.

Physiologically-Based Pharmacokinetic Modeling Characterizes the CYP3A-Mediated Drug-Drug Interaction Between Fluconazole and Sildenafil in Infants

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Clinical Pharmacology & Therapeutics • January 2021

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Salerno SN, Edginton A, Gerhart JG, Laughon MM, Ambalavanan N, Sokol GM, Hornik CD, Stewart D, Mills M, Martz K, Gonzalez D; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee
Infants being treated for pulmonary hypertension and prevention or treatment of invasive candidiasis may be given sildenafil with fluconazole concurrently. Physiologically-based pharmacokinetic (PBPK) modeling can potentially predict pediatric drug-drug interactions (DDIs) when clinical DDI data are limited. This study highlights the feasibility of PBPK modeling to predict DDIs in infants and the need to include CYP3A7 parameters.

Population Pharmacokinetics of Metoclopramide in Infants, Children, and Adolescents

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Clinical and Translational Science • November 2020

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Ge S, Mendley SR, Gerhart JG, Melloni C, Hornik CP, Sullivan JE, Atz A, Delmore P, Tremoulet A, Poindexter BB, Harper B, Payne E, Lin S, Erinjeri J, Cohen-Wolkowiez M, Gonzalez D
Metoclopramide is commonly used for gastroesophageal reflux. The aims of the present study were to develop a pediatric population pharmacokinetic (PopPK) model, which was applied to simulate the metoclopramide exposure following dosing used in clinical practice. The study suggests that a metoclopramide dose as previously recommended for pediatric patients results in simulated exposure generally within suggested ranges for the treatment of gastroesophageal reflux.

Safety of Metronidazole in Late Preterm and Term Infants With Complicated Intraabdominal Infections

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Pediatric Infectious Disease Journal • September 2020

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Commander SJ, Gao J, Zinkhan EK, Heresi G, Courtney SE, Lavery AP, Delmore P, Sokol GM, Moya F, Benjamin DK Jr, Bumpass TG, Debski J, Erinjeri J, Sharma G, Tracy ET, Cohen-Wolkowiez M, Hornik CP; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee

Metronidazole is frequently used off-label in infants with complicated intra-abdominal infections (cIAI) to provide coverage against anaerobic organisms, but its safety and efficacy in this indication are unknown. Metronidazole safety was evaluated by reporting of adverse events (AEs) and safety events of special interest. In a cohort of late pre-term and term infants with cIAIs, combination antibiotic therapy that included metronidazole was safe, and therapeutic success was high.

CYP2B6 Genotype Affects Methadone Disposition in Children as Demonstrated by Physiologically-Based Pharmacokinetic (PBPK) Modeling

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Clinical Pharmacology and Therapeutics • March 2020

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Gerhart JG, Edginton A, Watt KM, Cohen-Wolkowiez M, Harper B, Muller W, Delmore P, Atz A, Gonzalez D; on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee

Meeting abstract from Annual Meeting of the American-Society-for-Clinical-Pharmacology-and-Therapeutics on March 18-21, 2020.

Dosing and Safety of Off-label Use of Caffeine Citrate in Premature Infants

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Journal of Pediatrics • August 2019

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Puia-Dumitrescu M, Smith PB, Zhao J, Soriano A, Payne EH, Harper B, Bendel-Stenzel E, Moya F, Chhabra R, Ku L, Laughon M, Wade KC

Aim to characterize the dosing and safety of off-label caffeine citrate in a contemporary cohort of extremely premature infants. We used electronic health records (2010-2013) from 4 neonatal intensive care units to identify infants of ≤28 weeks of gestational age exposed to caffeine citrate. Of 410 infants with a median (IQR) gestational age of 26 (24-27) weeks, 95% received caffeine citrate for >0 days. Infants received a median (IQR) daily dose of 8 (5-10) mg/kg/day. Incidences of clinical events on day of caffeine citrate exposure were death 2%, patent ductus arteriosus ligation 12%, and medical and surgical necrotizing enterocolitis 5% and 4%, respectively.