Evaluation of three antibiotic programs in newborn infants.

Emergence of gram-negative bacteria resistnant to a number of antibiotics in intensive care nurseries for neonates emphasizes the need for alternatives in antibiotic combinations. One commonly used combination, gentamicin-ampicillin, and two newer combinations, tobramycin-cephalothin and amikacinampicillin, were evaluated prospectively in 60 newborns in such a nursery. Subjects were randomly assigned to one of the above therapy groups. Dosages in mg/kg.d were 100 for ampicillin and cephalothin, 6 for gentamicin and tobramycin and 15 for amikacin. Aminoglycoside serum concentrations, clinical tolerance and toxicity were monitored. Aminoglycoside concentrations after intravenous administration of the drugs were within the expected range (gentamicin and tobramycin 4 to 6 microgram/mL and amikacin 15 to 20 microgram/mL). There was no hematologic, renal or hepatic toxicity attributable to antibiotic therapy and the combinations were tolerated equally; no bilirubin displacement was detected in vitro or in vivo.