Pharmacokinetics

Dexmedetomidine Pharmacokinetics and a New Dosing Paradigm in Infants Supported With Cardiopulmonary Bypass

Posted on by Kayla Korzekwinski

Anesthesia & Analgesia • December 2019

Access article on PubMed.

Zimmerman KO, Wu H, Laughon M, Greenberg RG, Walczack R, Schulman SR, Smith PB, Hornik CP, Cohen-Wolkowiez M, Watt KM

Dexmedetomidine is increasingly used off-label in infants and children with cardiac disease during cardiopulmonary bypass (CPB) and in the postoperative period. Despite its frequent use, optimal dosing of dexmedetomidine in the setting of CPB has not been identified but is expected to differ from dosing in those not supported with CPB. This study had the following aims: (1) characterize the effect of CPB on dexmedetomidine clearance (CL) and volume of distribution (V) in infants and young children; (2) characterize tolerance and sedation in patients receiving dexmedetomidine; and (3) identify preliminary dosing recommendations for infants and children undergoing CPB.

Rifampin Pharmacokinetics and Safety in Preterm and Term Infants

Posted on by Kayla Korzekwinski

Antimicrobial Agents and Chemotherapy • May 2019

Access article on PubMed.

Smith PB, Cotten CM, Hudak ML, Sullivan JE, Poindexter BB, Cohen-Wolkowiez M, Boakye-Agyeman F, Lewandowski A, Anand R, Benjamin DK Jr, Laughon MM; Best Pharmaceuticals for Children Act—Pediatric Trials Network Steering Committee.

Rifampin is active against methicillin-resistant staphylococcal species and tuberculosis (TB). We performed a multicenter, prospective pharmacokinetic (PK) and safety study of intravenous rifampin in infants of <121 days postnatal age (PNA). We enrolled 27 infants; the median (range) gestational age was 26 weeks (23 to 41 weeks), and the median PNA was 10 days (0 to 84 days). We collected 102 plasma PK samples from 22 of the infants and analyzed safety data from all 27 infants. We analyzed the data using a population PK approach.

Pharmacokinetics of ticarcillin-clavulanate in premature infants

Posted on by Kayla Korzekwinski

British Journal of Clinical Pharmacology • May 2019

Access article on PubMed.

Watt KM, Hornik CP, Balevic SJ, Mundakel G, Cotten CM, Harper B, Benjamin DK, Anand R, Laughon M, Smith PB, Cohen-Wolkowiez M; Best Pharmaceuticals for Children Act Pediatric Trials Network Steering Committee

Ticarcillin-clavulanate covers a broad spectrum of pathogens that are common in premature infants. In infants <30 weeks gestational age, pharmacokinetic data to guide ticarcillin-clavulanate dosing are lacking. This study enrolled premature infants <30 weeks gestational age, determined pharmacokinetic parameters, and performed dosing simulations to determine optimal dosing for ticarcillin-clavulanate.

Physiologically-Based Pharmacokinetic Modeling of Fluconazole Using Plasma and Cerebrospinal Fluid Samples From Preterm and Term Infants

Posted on by Kayla Korzekwinski

CPT: Pharmacometrics & Systems Pharmacology • May 2019

Access article on PubMed.

Gerhart JG, Watt KM, Edginton A, Wade KC, Salerno SN, Benjamin DK, Smith PB, Hornik CP, Cohen-Wolkowiez M, Duara S, Ross A, Shattuck K, Stewart DL, Neu N, Gonzalez D, on behalf of the Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee

Fluconazole is used to treat hematogenous Candida meningoencephalitis in preterm and term infants. To characterize plasma and central nervous system exposure, an adult fluconazole physiologically-based pharmacokinetic (PBPK) model was scaled to infants, accounting for age dependencies in glomerular filtration and metabolism. Target attainment in plasma and CSF was reached faster after incorporating a loading dose of 25 mg/kg. PBPK modeling can be useful in exploring CNS kinetics of drugs in children.

Product Labeling of Drugs Commonly Administered to Children and Adults with Obesity

Posted on by Kayla Korzekwinski

Pharmaceutical Regulatory Affairs • April 2019

Access article on PubMed.

Zimmerman KO, Benjamin DK ,Becker ML, Anand R, Hornik CP

Obesity is a major public health problem that can affect drug disposition and dosing, particularly in vulnerable pediatric populations. Despite potentially detrimental consequences from inappropriately dosed drugs in children with obesity, drug product labels largely fail to include dosing or guidance specific to this population. Using data from the PTN, this study explored possible ways to improve drug labeling in children with obesity.

Pharmacokinetics of Hydroxychloroquine in Pregnancies with Rheumatic Diseases

Posted on by Kayla Korzekwinski

Clinical Pharmacokinetics • April 2019

Access article on PubMed.

Balevic SJ, Green TP, Clowse MEB, Eudy AM, Schanberg LE, Cohen-Wolkowiez M

 Hydroxychloroquine is an oral drug prescribed to pregnant women with rheumatic disease to reduce disease activity and prevent flares. Physiologic changes during pregnancy may substantially alter drug pharmacokinetics. However, the effect of pregnancy on hydroxychloroquine disposition and the potential need for dose adjustment remains virtually unknown. This study developed a one-compartment population-pharmacokinetic model for hydroxychloroquine in pregnant women with rheumatic disease.

Sildenafil Exposure in the Neonatal Intensive Care Unit

Posted on by Kayla Korzekwinski

American Journal of Perinatology • February 2019

Access article on PubMed.

Thompson EJ, Perez K, Hornik CP, Smith PB, Clark RH, Laughon M; Best Pharmaceuticals for Children Act—Pediatric Trials Network Steering Committee

Pulmonary hypertension causes substantial morbidity and mortality in infants. Although Food and Drug Administration approved to treat pulmonary arterial hypertension in adults, sildenafil is not approved for infants. This study sought to describe sildenafil exposure and associated diagnoses and outcomes in infants.

Population Pharmacokinetics and Exploratory Exposure-Response Relationships of Diazepam in Children Treated for Status Epilepticus

Posted on by Kayla Korzekwinski

CPT Pharmacometrics & Systems Pharmacology • November 2018

Access article on PubMed.

Ku LC, Hornik CP, Beechinor RJ, Chamberlain JM, Guptill JT, Harper B, Capparelli EV, Martz K, Anand R, Cohen-Wolkowiez M, Gonzalez D; Best Pharmaceuticals for Children Act – Pediatric Trials Network Steering Committee.

Diazepam is labeled for status epilepticus (SE) in children, but there are limited data characterizing its disposition in pediatric patients. We developed a population pharmacokinetic (PK) model of i.v. diazepam in children with SE. We evaluated relationships between PK parameters and both safety and efficacy, and simulated exposures using dosing regimens from the product label and clinical practice.

A Population-Based Pharmacokinetic Model Approach to Pantoprazole Dosing for Obese Children and Adolescents

Posted on by Kayla Korzekwinski

Pediatric Drugs • October 2018

Access article on PubMed.

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

Pharmacokinetic data for proton pump inhibitors (PPIs), acid-suppression drugs commonly prescribed to children, are lacking for obese children who are at greatest risk for acid-related disease. In a recent multi-center investigation, we demonstrated decreased, total body weight adjusted, apparent clearance (CL/F) of the PPI pantoprazole for obese children compared with their non-obese peers.

A pharmacokinetic model for amiodarone in infants developed from an opportunistic sampling trial and published literature data

Posted on by Kayla Korzekwinski

Journal of Pharmacokinetics and Pharmacodynamics • June 2018

Access article on PubMed.

Dallefeld SH, Atz AM, Yogev R, Sullivan JE, Al-Uzri A, Mendley SR, Laughon M, Hornik CP, Melloni C, Harper B, Lewandowski A, Mitchell J, Wu H, Green TP, Cohen-Wolkowiez M.

Amiodarone is a first-line antiarrhythmic for life-threatening ventricular fibrillation or ventricular tachycardia in children, yet little is known about its pharmacokinetics (PK) in this population. We developed a population PK (PopPK) model using samples collected via an opportunistic study design of children receiving amiodarone per standard of care supplemented by amiodarone PK data from the literature.