Drug disposition

Physiologically Based Pharmacokinetic Modeling of Oxcarbazepine to Characterize Its Disposition in Children with Obesity

Posted on by Jeannine Sato

Journal of Clinical Pharmacology, September 2025

Access article on PubMed.

Maglalang PD, Sinha J, Helfer VE, Edginton A, Zimmerman K, Hornik CD, Muller WJ, Rathore M, Benjamin DK Jr, Chen JY, Anand R, Gonzalez D; Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee. 

Oxcarbazepine (OXC) is a second-generation antiseizure medication, effective through its active metabolite, 10-mono-hydroxy derivative (MHD). OXC is used as adjunctive therapy for focal-onset and primary generalized tonic-clonic seizures, with recommended dosing based on age and body weight. This study uses physiologically based pharmacokinetic (PBPK) modeling and leverages pharmacokinetic (PK) data acquired from children enrolled in pragmatic trials to understand dosing and subsequent exposure requirements in children with obesity. 

Physiologically Based and Population Pharmacokinetic Modeling of Midazolam in Children With Obesity Using Real-World Data

Posted on by Jeannine Sato

Clinical and Translational Science, May 2025

Access article on PubMed.

McCann S, Helfer VE, Balevic SJ, Muller WJ, van den Anker JN, Al-Uzri A, Meyer ML, Anderson SG, Turdalieva S, Edginton AN, Gonzalez D; Best Pharmaceuticals for Children Act Pediatric Trials Network Steering Committee.

Midazolam has been used as a sedative for hospitalized children on- and off-label; however, factors affecting interindividual variability (IIV) in observed clearance for this population are not fully understood and can result in extreme under- or overexposure. Obesity has been described as a significant influence on midazolam in adolescents, which could potentially alter drug exposure. The goal of this study was to use two modeling strategies to evaluate dose-exposure of midazolam in children with and without obesity. 

Population Pharmacokinetics of Meropenem Across the Adult Lifespan

Posted on by Kayla Korzekwinski

Clinical Pharmacokinetics • February 2025

Access article on PubMed.

Boutzoukas AE, Balevic SJ, Hemmersbach-Miller M, Winokur PL, Gu K, Chan AW, Cohen-Wolkowiez M, Conrad T, An G, Kirkpatrick CMJ, Swamy GK, Walter EB, Schmader KE, Landersdorfer CB.

This study conducted an opportunistic pharmacokinetic study to evaluate the population pharmacokinetics of meropenem, an antimicrobial commonly used to treat Gram-negative infections in adults of different ages, including older adults, and determined optimal dosing regimens. Meropenem dosing should be based on renal function rather than age. For patients without renal impairment, extended infusion may increase the probability of target attainment.

 

Predictors of Potentially Inappropriate Stimulant Prescribing Among Adults

Posted on by Kayla Korzekwinski

Pharmacoepidemiology and Drug Safety • January 2025

Access article on PubMed.

Thakkar PV, Boutzoukas AE, Compton SN, Sivashankar O, Zimmerman KO, Benjamin DK Jr, Brookhart MA

Increases in adult stimulant prescribing pose a potential risk due to the higher prevalence of contraindicated conditions among this population. This study sought to identify patient, provider, and visit characteristics predictive of potentially inappropriate adult stimulant prescriptions. The proportion of potentially inappropriate adult stimulant prescriptions increased over time and with patient age. Visits to primary care providers were predictive of potentially inappropriate prescribing, and a history of substance abuse was predictive of new stimulant prescriptions; therefore, quality improvement interventions regarding safe stimulant prescribing practices may be warranted.

Pharmacokinetics of Dexamethasone in Children and Adolescents with Obesity

Posted on by Kayla Korzekwinski

The Journal of Clinical Pharmacology • August 2024

Access article on PubMed.

Wen J, McCann S, Balevic S, Muller WJ, Hornik C, Autmizguine J, Anderson SG, Payne EH, Turdalieva S, Gonzalez D., Best Pharmaceuticals for Children Act – Pediatric Trials Network

Dexamethasone is a synthetic glucocorticoid approved for treating disorders of various organ systems in both adult and pediatric populations. Currently, approved pediatric dosing recommendations are weight-based, but it is unknown whether differences in dexamethasone drug disposition and exposure exist for children with obesity. This study aimed to develop a population pharmacokinetic (PopPK) model for dexamethasone with data collected from children with obesity.

Physiologically-based pharmacokinetic modeling of pantoprazole to evaluate the role of CYP2C19 genetic variation and obesity in the pediatric population

Posted on by Kayla Korzekwinski

CPT: Pharmacometrics & Systems Pharmacology • August 2024

Access article on PubMed.

Thompson EJ, Jeong A, Helfer VE, Shakhnovich V, Edginton A, Balevic SJ, James LP, Collier DN, Anand R, Gonzalez D., Best Pharmaceuticals for Children Act – Pediatric Trials Network

Pantoprazole is a proton pump inhibitor indicated for the treatment of gastroesophageal reflux disease, a condition that disproportionately affects children with obesity. Appropriately dosing pantoprazole in children with obesity requires understanding the body size metric that best guides dosing, but pharmacokinetic (PK) trials using traditional techniques are limited by the need for larger sample sizes and frequent blood sampling. This study explored the effect of obesity on pantoprazole PK and evaluated label-suggested dosing in this population.

Using Real-World Data to Externally Evaluate Population Pharmacokinetic Models of Dexmedetomidine in Children and Infants

Posted on by Kayla Korzekwinski

The Journal of Clinical Pharmacology • August 2024

Access article on PubMed.

McCann S, Helfer VE, Balevic SJ, Hornik CH, Goldstein SL, Autmizguine J, Meyer M, Al-Uzri A, Anderson SG, Payne EH, Turdalieva S, Gonzalez D., Best Pharmaceuticals for Children Act – Pediatric Trials Network

Dexmedetomidine is a sedative used in both adults and off-label in children with considerable reported pharmacokinetic (PK) interindividual variability affecting drug exposure across populations. Several published models describe the population PKs of dexmedetomidine in neonates, infants, children, and adolescents, though very few have been externally evaluated. A prospective PK dataset of dexmedetomidine plasma concentrations in children and young adults aged 0.01-19.9 years was collected as part of a multicenter opportunistic PK study.

Epidemiology and outcomes of bacterial meningitis in the neonatal intensive care unit

Posted on by Kayla Korzekwinski

Journal of Perinatology • July 2024

Access article on PubMed.

Aleem S, Benjamin DK Jr, Burns C, Duncan J, Melaku K, Norbekov A, Graham B, Mantena S, Ladipo T, Jung A, Zimmerman KO, Clark RH, Greenberg RG

This study examined pathogen distribution, antibiotic resistance patterns, and hospital outcomes of infants with bacterial meningitis in neonatal intensive care units (NICUs) in the US from 2013-2018.

Application of Physiologically Based Pharmacokinetic Modeling to Characterize the Effects of Age and Obesity on the Disposition of Levetiracetam in the Pediatric Population

Posted on by Kayla Korzekwinski

Clinical Pharmacokinetics • June 2024

Access article on PubMed.

Maglalang PD, Sinha J, Zimmerman K, McCann S, Edginton A, Hornik CP, Hornik CD, Muller WJ, Al-Uzri A, Meyer M, Chen L, Anand R, Perrin E, Gonzalez D., Best Pharmaceuticals for Children Act–Pediatric Trials Network Steering Committee

Levetiracetam is an antiseizure medication used for several seizure types in adults and children aged 1 month and older; however, due to a lack of data, pharmacokinetic (PK) variability of levetiracetam is not adequately characterized in certain populations, particularly neonates, children younger than 2 years of age, and children older than 2 years of age with obesity. PBPK modeling simulations revealed that the current US FDA-labeled pediatric dosing regimen listed in the prescribing information can produce the required exposure of levetiracetam in these target populations with dose adjustments for children with obesity aged 4 years to younger than 16 years.

Urinary Tract Infection Epidemiology in NICUs in the United States

Posted on by Kayla Korzekwinski

American Journal of Perinatology • May 2024

Access article on PubMed.

Kilpatrick R, Boutzoukas AE, Chan E, Girgis V, Kinduelo V, Kwabia SA, Yan J, Clark RH, Zimmerman KO, Greenberg RG

This study characterized the incidence, associated clinical factors, timing of infection, microbiology, and incidence of concordant blood culture of urinary tract infections (UTIs) in very low birth weight (VLBW <1,500g) infants. UTI is a common cause of infection in VLBW infants, especially among the smallest, most premature, male infants, and those with a longer duration of hospitalization. Neonatal clinicians should consider obtaining urine culture in the setting of late-onset sepsis evaluations in VLBW infants.