Performance of a dosage individualization table for extended interval gentamicin in neonates beyond the first week of life

Abstract

Objective: To assess the performance of a gentamicin dosing table for the individualization of extended-interval dosing (EID) in a neonatal population >7 days old.

Methods: A prospective observational study was carried out on gentamicin concentrations achieved using a dosing table in neonates >7 days old. Neonates were given 5 mg/kg IV gentamicin; then a table using 22 h post-first dose gentamicin concentrations was used to individualize dosing intervals. Pre- and post-serum gentamicin concentrations were measured and used to calculate the true peak and trough concentrations achieved.

Results: Use of the table resulted in dosing intervals that provided appropriate peak (mean 9.8 ± 1.8 mg/L) and trough (mean 0.6 ± 0.3 mg/L) concentrations in all neonates (n = 38). All trough concentrations were <2 mg/L, 83% were <1 mg/L. The majority of peak concentrations were in the usual target range (87%, 5–12 mg/L), with a few being in a higher, although likely safe range (13%, 12.1–15.7 mg/L).

Conclusions: Use of this dosing table to individualize extended-interval gentamicin dosages in neonates >7 days old resulted in appropriate peak and trough concentrations in all neonates studied. This allows appropriate extended-interval aminoglycoside dosages in neonates early in treatment.

Keywords:

• Aminoglycosides – administration and dosage
• aminoglycosides – pharmacokinetics
• Infant – newborn

Declaration of interest

The authors report no declarations of interest.

This study received no outside funding.