[Relevance and applications of systematic quantitative determinations of gentamicin during the neonatal period...

We have used an enzyme immunoassay method to measure serum levels of gentamicin in neonates according to gestational age, birth weight, dosage and intervals of intramuscular injections. Peak, predose serum levels and half-life decrease when gestational age increase. For the same gestational age, peak serum levels decrease in small weight neonates. Toxic postdose serum levels were obtained in preterm neonates with a daily regimen exceeding 5 mg/kg. Serum concentration monitoring of gentamicin is recommended to ensure adequate dosage and interval of injections.