Methods: Blood samples (2–4 per child) were collected from 13 children ages 9 months to 6
years admitted to the pediatric intensive care unit who were receiving standard piperacillin/
tazobactam dosing regimens to treat infections. Piperacillin concentrations were measured
by a bioassay, and the population pharmacokinetics of the piperacillin component was
conducted using nonparametric adaptive grid (BigNPAG) with adaptive γ. Multiple models
were tested to determine the best fit of the data. A 5000 patient Monte Carlo simulation was …

Objectives To develop population pharmacokinetic (PK) models for piperacillin/tazobactam
in neonates and infants of less than 2 months of age in order to determine the appropriate
dosing regimen and provide a rational basis for the development of preliminary dosing
guidelines suitable for this population. Methods A two-stage, open-label study was
conducted in neonates and infants less than 2 months of age in the neonatal intensive care
unit (NICU). A total of 207 piperacillin and 204 tazobactam concentration–time data sets …