Pharmacokinetics

Population Pharmacokinetics of Intramuscular and Intravenous Ketamine in Children

Posted on by Kayla Korzekwinski

The Journal of Clinical Pharmacology • April 2018

Access article on PubMed.

Hornik CP, Gonzalez D, van den Anker J, Atz AM, Yogev R, Poindexter BB, Ng KC, Delmore P, Harper BL, Melloni C, Lewandowski A, Gelber C, Cohen-Wolkowiez M, Lee JH; Pediatric Trial Network Steering Committee.

Ketamine is an N-methyl D-aspartate receptor antagonist used off-label to facilitate dissociative anesthesia in children undergoing invasive procedures. Available for both intravenous and intramuscular administration, ketamine is commonly used when vascular access is limited. Pharmacokinetic (PK) data in children are sparse, and the bioavailability of intramuscular ketamine in children is unknown.

Obese Children Require Lower Doses of Pantoprazole Than Nonobese Peers to Achieve Equal Systemic Drug Exposures

Posted on by Kayla Korzekwinski

The Journal of Pediatrics • February 2018

Access article on PubMed.

Shakhnovich V, Smith PB, Guptill JT, James LP, Collier DN, Wu H, Livingston CE, Zhao J, Kearns GL; Best Pharmaceuticals for Children Act – Pediatric Trials Network.

To assess appropriate pantoprazole dosing for obese children, we conducted a prospective pharmacokinetics (PK) investigation of pantoprazole in obese children, a patient population that is traditionally excluded from clinical trials. A total of 41 obese children (6-17 years of age), genotyped for CYP2C19 variants *2, *3, *4, and *17, received a single oral dose of pantoprazole, ~1.2 mg/kg lean body weight (LBW), with LBW calculated via a validated formula.

Comparative Analysis of Ampicillin Plasma and Dried Blood Spot Pharmacokinetics in Neonates

Posted on by Kayla Korzekwinski

Therapeutic Drug Monitoring • February 2018

Access article on PubMed.

Le J, Poindexter B, Sullivan JE, Laughon M, Delmore P, Blackford M, Yogev R, James LP, Melloni C, Harper B, Mitchell J, Benjamin DK Jr, Boakye-Agyeman F, Cohen-Wolkowiez M.

Dried blood spot (DBS) is a practical sampling strategy for pharmacokinetic studies in neonates. The utility of DBS to determine the population pharmacokinetics (pop-PK) of ampicillin, as well as accuracy versus plasma samples, was evaluated. An open-label, multicenter, opportunistic, prospective study was conducted in neonates.

Population Pharmacokinetics of Trimethoprim-Sulfamethoxazole in Infants and Children

Posted on by Kayla Korzekwinski

Antimicrobial Agents and Chemotherapy • December 2017

Access article on PubMed.

Autmizguine J, Melloni C, Hornik CP, Dallefeld S, Harper B, Yogev R, Sullivan JE, Atz AM, Al-Uzri A, Mendley S, Poindexter B, Mitchell J, Lewandowski A, Delmore P, Cohen-Wolkowiez M, Gonzalez D; the Pediatric Trials Network Steering Committee.

Trimethoprim (TMP)-sulfamethoxazole (SMX) is used to treat various types of infections, including community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) and Pneumocystis jirovecii infections in children. Pharmacokinetic (PK) data for infants and children are limited, and the optimal dosing is not known. We performed a multicenter, prospective PK study of TMP-SMX in infants and children.

Population Pharmacokinetics of Dexmedetomidine in Infants

Posted on by Kayla Korzekwinski

Journal of Clinical Pharmacology • September 2017

Access article on PubMed.

Greenberg RG, Wu H, Laughon M, Capparelli E, Rowe S, Zimmerman KO, Smith PB, Cohen-Wolkowiez M

Despite limited pharmacokinetic (PK) data, dexmedetomidine is increasingly being used off-label for sedation in infants. This study aimed to characterize the developmental PK changes of dexmedetomidine during infancy.

Use of Population Pharmacokinetics and Electronic Health Records to Assess Piperacillin-Tazobactam Safety in Infants

Posted on by Kayla Korzekwinski

The Pediatric Infectious Disease Journal • September 2017

Access article on PubMed.

Salerno S, Hornik CP, Cohen-Wolkowiez M, Smith PB, Ku LC, Kelly MS, Clark R, Gonzalez D; Best Pharmaceuticals for Children Act–Pediatric Trials Network Steering Committee.

Piperacillin, in combination with tazobactam, is frequently used in infants for treating nosocomial infections, although safety data in this population are limited. Electronic health record (EHR) data can be used to evaluate drug safety in infants, but measures of drug exposure are lacking. To relate simulated piperacillin exposure with adverse events (AEs) in infants using EHR data, we identified infants discharged from 333 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012.

Population Pharmacokinetics and Exploratory Pharmacodynamics of Lorazepam in Pediatric Status Epilepticus

Posted on by Kayla Korzekwinski

Clinical Pharmacokinetics • August 2017

Access article on PubMed.

Gonzalez D, Chamberlain JM, Guptill JT, Cohen-Wolkowiez M, Harper B, Zhao J, Capparelli EV; Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee.

Lorazepam is one of the preferred agents used for intravenous treatment of status epilepticus (SE). We combined data from two pediatric clinical trials to characterize the population pharmacokinetics of intravenous lorazepam in infants and children aged 3 months to 17 years with active SE or a history of SE.

Pharmacokinetics of Clindamycin in Obese and Nonobese Children

Posted on by Kayla Korzekwinski

Antimicrobial Agents and Chemotherapy • March 2017

Access article on PubMed.

Smith MJ, Gonzalez D, Goldman JL, Yogev R, Sullivan JE, Reed MD, Anand R, Martz K, Berezny K, Benjamin DK Jr, Smith PB, Cohen-Wolkowiez M, Watt K; Best Pharmaceuticals for Children Act—Pediatric Trials Network Steering Committee.

Although obesity is prevalent among children in the United States, pharmacokinetic (PK) data for obese children are limited. Clindamycin is a commonly used antibiotic that may require dose adjustment in obese children due to its lipophilic properties. We performed a clindamycin population PK analysis using data from three separate trials. A total of 420 samples from 220 children, 76 of whom had a body mass index greater than or equal to the 95th percentile for age, were included in the analysis. Compared to other metrics, total body weight (TBW) was the most robust measure of body size.

Metronidazole Metabolism in Neonates and the Interplay Between Ontogeny and Genetic Variation

Posted on by Kayla Korzekwinski

The Journal of Clinical Pharmacology • February 2017

Access article on PubMed.

Wang LA, Gonzalez D, Leeder JS, Tyndale RF, Pearce RE, Benjamin DK Jr, Kearns GL, Cohen-Wolkowiez M; Best Pharmaceuticals for Children Act-Pediatric Trials Network Steering Committee.

Metronidazole is commonly used to treat intra-abdominal infections in neonates. The parent drug is converted to 5 metabolites, with 2-hydroxy-metronidazole being the most clinically significant, as it possesses 30–65% of the antimicrobial activity of the parent compound. In vitro studies have demonstrated that cytochrome P450 2A6 (CYP2A6) is the primary catalyst responsible for metronidazole hydroxylation. This enzyme is initially expressed at low levels at birth, with expression increasing over the course of the first year of life to reach adult levels. CYP2A6 is known to be a highly polymorphic gene with more than 45 variant alleles that result in inactive to ultra-rapid metabolizer phenotypes. Additionally, certain allelic variants such as CYP2A6*17 have amino acid changes that alter metabolism for some but not other substrates, resulting in different metabolizing phenotypes for the same genotype. The role of genetic variation on variable metronidazole metabolism in neonates has not been previously described, nor has the effect of CYP2A6*17 on metronidazole been characterized. As such, the objective of this study was to evaluate the effect of CYP2A6 genetic variation on the pharmacokinetics of metronidazole in a small cohort of preterm neonates.

Safety of High-dose Acyclovir in Infants With Suspected and Confirmed Neonatal Herpes Simplex Virus Infections

Posted on by Kayla Korzekwinski

The Pediatric Infectious Disease Journal • December 2016

Access article on PubMed.

Ericson JE, Gostelow M, Autmizguine J, Hornik CP, Clark RH, Benjamin DK Jr, Smith PB; Pediatric Trials Network Executive Committee and Investigators.

Acyclovir is used to treat herpes simplex virus disease in infants. Treatment with high-dose acyclovir, 60 mg/kg/d, is recommended; however, the safety of this dosage has not been assessed in the past 15 years, and this dosage is not currently approved for infants by the US Food and Drug Administration. We included infants with neonatal herpes simplex virus disease treated with ≥14 days of intravenous acyclovir starting in the first 120 days of life admitted to 1 of 42 neonatal intensive care units managed by the Pediatrix Medical Group between 2002 and 2012.