Meropenem Pharmacokinetics in the Newborn

venous infusion) on a random basis. Blood was obtained for determining the meropenem concentration nine times. Each child required other antimicrobials for proven/suspected bacterial infections. Samples were assayed by high-performance liquid chromatography analysis. Population pharmacokinetic parameter values were obtained by employing the BigNPAG program. Model building was performed by the likelihood ratio test. The final model included estimated creatinine clearance (CLcr) (Schwartz formula) and weight (Wt) in the calculation of clearance (meropenem clearance 0.00112 CLcr 0.0925 Wt 0.156 liter/hr). The overall fit of the model to the data was good (observed 1.037 predicted 0.096; r2 0.977). Given the distributions of estimated creatinine clearance and weight between pre-term and full-term neonates, meropenem clearance was substantially higher in the full-term group. A Monte Carlo simulation was performed using the creatinine clearance and weight distribu