[Study of intravenous cefotaxime therapy in neonates]

It has been proven that, when cephem group antibiotics are administered intravenously to neonates, the peak serum level of the drug is higher, and the half-life is longer, compared with the values attained in suckling infants. The same pattern is seen even with cefmetazole. This is, the Post- and Perinatal Period Research Group recently reported that, when 20 mg/kg of cefmetazole was administered intravenously, the mean serum half-life of the drug was 4.18 hours in infants up to 3 days after birth, while by about the age of 2 weeks there was no longer a difference with suckling infants. In the present study, cefotaxime was administered at a dosage level of 20 mg/kg by intravenous drip infusion over a 30-minute period. The administered subjects were a 16-day-old neonate and a 45-day-old suckling infant, and the serum level of cefotaxime was monitored. The peak concentration was found to be higher in the younger subject, and the half-life in the serum was longer, i.e., 2.52 hours compared with 1.5 hours in the suckling infant. In addition, 4 cases of newborn infection were treated with cefotaxime at 120--504 mg/day (approximately 35--300 mg/kg/day), given intravenously for a period of 6 to 21 days. Clear clinical efficacy and bacteriological efficacy were achieved in relation to 1 case of staphylococcal pneumonia, 1 case of septicemia compounded by purulent meningitis caused by Enterobacter aerogenes and 1 case of fever of undetermined origin. The following summarizes the results of the present study. 1) There was no adverse effect exerted on the hepatic or renal functions. 2) Cefotaxime was efficacious in the treatment of neonates suffering from infections caused by staphylococci and a Gram-negative rod.