Metabolomics applied in neonatology

Effect of Kidney Function on Drug Kinetics and Dosing in Neonates, Infants, and Children

Neonates, infants, and children differ from adults in many aspects, not just in age, weight, and body composition. Growth, maturation and environmental factors affect drug kinetics, response and dosing in pediatric patients. Almost 80% of drugs have not been studied in children, and dosing of these drugs is derived from adult doses by adjusting for body weight/size. As developmental and maturational changes are complex processes, such simplified methods may result in subtherapeutic effects or adverse events. Kidney function is impaired during the first 2 years of life as a result of normal growth and development. Reduced kidney function during childhood has an impact not only on renal clearance but also on absorption, distribution, metabolism and nonrenal clearance of drugs. 'Omics'-based technologies, such as proteomics and metabolomics, can be leveraged to uncover novel markers for kidney function during normal development, acute kidney injury, and chronic diseases. Pharmacometric modeling and simulation can be applied to simplify the design of pediatric investigations, characterize the effects of kidney function on drug exposure and response, and fine-tune dosing in pediatric patients, especially in those with impaired kidney function. One case study of amikacin dosing in neonates with reduced kidney function is presented. Collaborative efforts between clinicians and scientists in academia, industry, and regulatory agencies are required to evaluate new renal biomarkers, collect and share prospective pharmacokinetic, genetic and clinical data, build integrated pharmacometric models for key drugs, optimize and standardize dosing strategies, develop bedside decision tools, and enhance labels of drugs utilized in neonates, infants, and children.

Neonatal medicines research: challenges and opportunities

INTRODUCTION

The key feature of the newborn is its fast age-dependent maturation, resulting in extensive variability in pharmacokinetics and -dynamics, further aggravated by newly emerging covariates like treatment modalities, environmental issues or pharmacogenetics. This makes clinical research in neonates relevant and needed, but also challenging.

AREAS COVERED

To improve this knowledge, tailoring research tools as well as building research networks and clinical research skills for neonates are urgently needed. Tailoring of research tools is illustrated using the development of dried blood spot techniques and the introduction of micro-dosing and -tracer methodology in neonatal drug studies. Both techniques can be combined with sparse sampling techniques through population modeling. Building research networks and clinical research skills is illustrated by the initiatives of agencies to build and integrate knowledge on neonatal pharmacotherapy through dedicated working groups.

EXPERT OPINION

Challenges relating to neonatal medicine research can largely be overcome. Tailored tools and legal initiatives, combined with clever trial design will result in more robust information on neonatal pharmacotherapy. This necessitates collaborative efforts between clinical researchers, sponsors, regulatory authorities, and last but not least patient representatives and society.