[Monitoring of gentamycin serum concentration in neonates. Usefulness in adjustment of dosage].
OBJECTIVE
The objective of this study was to confirm the variation of the pharmacokinetic parameters of gentamicin in neonates and to establish guidelines for a dosage regimen.


METHODS
A study was made of 89 neonates being treated with gentamicin. The gestational ages ranged from 25 to 41 weeks and the postnatal age between 1 and 30 days. Weights were between 600 and 4,400 grams. The average dose was 2.45 +/- 0.4 mg/kg/dose. Groups were established according to gestational age (under 34 weeks, 34-37 weeks and over 37 weeks) and postnatal age (over and under 7 days old).


RESULTS
The elimination half-life (t1/2) was significantly reduced (p < 0.01) in the different age groups. The distribution volume (V) showed a slight decrease corresponding to the gestational age, but this was not significant. The results suggest that the dosages applied in mg/kg were sufficient to attain potentially therapeutic peak blood levels (Cmax). However, the dosage should be administered at different intervals according to the age groups in order to allow the trough levels (Cmin) to come down to values which are considered to be therapeutic.


CONCLUSIONS
An interval of 24 hours is recommended for preterm babies with a postnatal age of less than 7 days and an interval of 12 hours for the remainder of the infant population.
García-Delgado
R
R
Unidad de Farmacología Clínica, Hospital General de Albacete.
Sánchez-Romero
A
A
Tébar-Gil
R
R
Marco-Macián
A
A
D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use*; D001835:Body Weight; D004305:Dose-Response Relationship, Drug; D005839:Gentamicins / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D012189:Retrospective Studies; D018805:Sepsis / Q000188:drug therapy*
D000900:Anti-Bacterial Agents; D005839:Gentamicins
Monitorización de niveles séricos de gentamicina en neonatos. Utilidad para el ajuste de dosis.