The need for a loading dose of gentamicin in neonates.
We studied pharmacokinetic variables in 100 neonates to evaluate the need for a loading dose of gentamicin. The mean volume of distribution for gentamicin in this population was .542 +/- .205 L/kg. Forty-five percent of these patients would not achieve peak serum concentrations of greater than or equal to 5 micrograms/ml after one dose of 2.5 mg/kg. A loading dose of 4 mg/kg would result in a level of greater than or equal to 5 micrograms/ml in 92% of the patients. After this study, a 4 mg/kg loading dose was initiated at our institution. Peak and trough concentrations at steady state were compared in 50 patients receiving a loading dose and 40 patients who had not received a loading dose. No significant differences were found in peak or trough concentrations after three or more doses, verifying that a loading dose does not affect steady-state concentrations. Because gentamicin toxicities are related to accumulation over time, whereas therapeutic efficacy may be related to early attainment of therapeutic peak serum concentrations, we recommend a loading dose of 4 mg/kg in all neonates beginning gentamicin therapy.
Watterberg
K L
KL
General Clinical Research Center, University of New Mexico, School of Medicine, Albuquerque 87131.
Kelly
H W
HW
Angelus
P
P
Backstrom
C
C
D005839:Gentamicins / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood*; D007235:Infant, Premature, Diseases / Q000097:blood; D007262:Infusions, Intravenous
D005839:Gentamicins