[Gentamicin pharmacokinetics in term newborn: ¿Is it necessary to systematically monitor plasmatic levels?].

BACKGROUND

Gentamicin is indicated as empiric treatment for neonatal sepsis. Plasmatic levels dosification of gentamicin is a common practice. The relationship between peak plasma concentration (Cmáx) with minimum inhibitory concentration (MIC) (Cmáx/MIC) is the parameter that best predicts treatment efficacy.

AIM: To determine pharmacokinetics of gentamicin in term newborn infants.

METHODS

Term newborn infants receiving gentamicin, without critical illness in which plasmatic levels of gentamicin was performed were included. Elimination clearance (Cl) elimination half-life (t½) and volume of distribution (Vd) were calculated. In each case the value of Cmax/MIC parameter was calculated, considering a MIC value of 1 μg/mL for Escherichia coli.

RESULTS

Thirteen newborns were included. The mean PK values were Cl: 0.26 mL/hour, Vd: 0.54 L/kg and t½: 6.8 h. Cmax/MIC was > 8 in 6 newborns.

CONCLUSIONS

Pharmacokinetic parameters of gentamicin are predictable in term newborn infants. With gentamicin doses normally used Cmax/MIC values reached 8 in 6 newborns. It is necessary to review the usefulness of plasma drug monitoring and gentamicin dosage in this group of newborns.