A multicenter evaluation of gentamicin therapy in the neonatal intensive care unit

Study Objective. To evaluate traditional nomogram (TN) versus individualized pharmacokinetic gentamicin dosing practices in neonatal intensive care units, focusing on achieving target therapeutic concentrations (peak > 8 μg/ml, trough < 2 μg/ml), number of dosing changes, number of concentrations obtained, and evidence of nephrotoxicity. Design. Retrospective chart review. Setting. Three neonatal intensive care units. Patients. Three hundred nine infants prescribed gentamicin. Intervention. None. Measurements and Main Results. Sixty-seven percent of patients receiving pharmacokinetic dosing had initial peak concentrations of 8 μg/ml or greater compared with 7% of patients receiving TN dosing (p<0.001). Trough concentrations exceeding 2 μg/ml were reported in 23% of patients receiving TN dosing compared with 2% of pharmacokinetic-dosed patients (p<0.001). Forty-two percent and 6%, respectively, required dosage adjustments (p<0.01). The mean number of concentrations obtained per patient was 2.8 and 2.1, respectively (p<0.01). Neither group had evidence of gentamicin-related nephrotoxicity. Conclusion. Compared with TN dosing, administering gentamicin loading doses and performing initial pharmacokinetic analysis resulted in rapid attainment of desired concentrations and fewer dosage adjustments, and allowed for a decrease in the number of gentamicin concentrations.