PHARMACOKINETICS OF NETILMICIN IN THE NEW BORNS WITH GESTATIONAL AGESGREATER-THAN-34 WEEKS

Background. - Neonatal bacterial infections are potentially lethal. Th e infant must be started on an antibiotic regimen to cover the organis ms most frequently implicated. Since the introduction of gentamicin th erapy for neonatal infections, attention has focused on aminoglycoside pharmacokinetics in these very young patients. Patients and methods. - The pharmacokinetics parameters of netilmicin during its first admin istration were analysed in 22 newborn infants with a gestational age o ver 34 weeks, aged 1 to 3 days, in whom a maternofetal infection was s uspected. Netilmicin was given intravenously at a dose of 6 mg/kg/day in two daily injections for 35 minutes. Blood concentrations of netilm icin were measured from samples taken 5, 15, 30, 60 minutes and 2 1/2, 5 1/5 and 11 1/2 hours after injection. The patients were also given cefotaxime plus ampicillin. Results. - The kinetics were bicompartimen tal: prematurity, proven infections and other perinatal factors influe nced the pharmacologic parameters and it was not possible to define a predictive formula for antibiotic administration. Conclusion. - The bl ood levels of netilmicin must be monitored even in infants who were no t born prematurely. Because of the large distribution volume and the l ong half-life, we propose a dose of 6-7.5 mg/kg given once daily.