Monitoring of amikacin in the neonate.

The purpose of this study was to analyze the role of gestational and postnatal age and of clinical conditions [e.g., respiratory distress syndrome (RDS)] on serum concentrations of amikacin in neonates treated according to commonly recommended dose schedules. Thirty-nine neonates (28.5-42 weeks of gestational age) were treated with the aminoglycoside at a mean dose of 7.2 mg/kg every 12 h for an average period of 6.5 days, and serum levels were monitored throughout treatment. Both gestational and postnatal age influenced amikacin levels. During the first days of life the presence of RDS was found to be strongly associated with amikacin accumulation. Neonates with retarded intrauterine growth according to their gestational age tended to have lower amikacin trough levels in the first days of life. No correlation was found between amikacin serum levels and hematocrit. Peak concentrations of the drug did not correlate with vital or clinical data, probably because of the variability in drug absorption from the intramuscular injection site. These data are discussed in light of the development of renal function and changes in body fluid compartments occurring in the preterm and term neonates during the first weeks of life.