[Pharmacokinetic study of cefotaxime in newborn infants and infants].

The serum kinetics of intravenous cefotaxime was studied in 13 neonates and 5 infants presenting with bacterial infections in order to establish the dosage and route of administration. Average dosage was 66.6 mg/kg/day in neonates and 62 mg/kg/day in infants. Cefotaxime was given intravenously in 3 daily bolus injections in infants and 2 bolus injections in neonates under 8 days of age. In infants the average serum peak was 173 mcg/ml at 15 min. Serum half-life was between 0.45 and 0.50 hr (T 1/2 beta) close to the one found in adults. In neonates the average serum peak was 106.2 mcg/ml at 35 min. Serum half-life was 1.71 hr (T 1/2 beta). It is prolonged in neonates who are younger, more premature and have a lower weight. In full term neonates, during the first 8 days, the desirable dose seems to be 75 to 150 mg/kg/day in 3 injections, according to the severity of the infection. In premature neonates under 8 days of age, the interval between injections should be increased up to 12 hrs. Finally, in full term neonates older than 8 days and in infants, one injection every 6 hours seems to be advisable.