Clinical pharmacology of tobramycin in infants.

Tobramycin was used in the treatment of severe infections in infants, mostly newborns and prematures. Serum half-life of the drug was 3.5 h in infants older than one week and above 2,500 g, and 8.0 h in infants below one week and less than 2,500 g. Apparent volume of distribution was similar in both groups, 0.24 l/kg. Intravenous infusions of the drug gave considerably higher plasma levels than intramuscular infections. Particularly in the newborn and premature group intramuscular injections gave fairly unpredictable plasma concentrations.