Fundamental and Clinical Studies of Cefotaxime in Neonates and Immature Infants

Cefotaxime (CTX) was used in the treatment and prophylaxis of infections in neonates and immature infants. The following results were obtained. 1. Mean serum concentrations (bioassay) 30 minutes after a single intravenous injection of about 20mg/ kg of CTX were 44.5 mcg/ml in neonates and 47.2mcg/ml in immature infants aged 0~3 days, 45.8 mcg/ml in neonates and 56.4 mcg/ml in an immature infant aged 4~7 days and 40.6mcg/ml in neonates and 38.1 mcg/ml in immature infants aged 8 or more days. Sixhour values were respectively 10.9 mcg/ml, 17.0 mcg/ml, 4.6 mcg/ml, 13.4 mcg/ml, 3.8mcg/ml and 2.7mcg/ml. 2. Mean serum concentration half-lives were 3.0 hours in neonates and 3.2 hours in immature infants aged 0~3 days, 1.8 hours in neonates and 3.2 hours in an immature infant aged 4~7 days, and 1.5 hours in neonates and 1. 6hours in immature infants aged 8 or more days. 3. Urinary recovery rates were 0.8~78.0% for 0~6 hours after treatment. 4. Adequate clinical efficacy can be expected by the intravenous injection of CTX in doses of 20 mg/kg 2 times daily, every 12 hours, in neonates and immature infants aged 0~3 days, 20 mg/kg 3 times daily, every 8 hours, in neonates and immature infants aged 4~7 days,and 20 mg/kg 3 to 4 times daily, every 6~8 hours, in neonates and immature infants aged 8 or more days. 5. The clinical efficacy of CTX was good in all 4 cases of sepsis (including suspected case), excellent in 1 case of urinary tract infection, and good in all 4 cases of fever of unknown origin for a cure rate of 100%. 6. Adverse reactions were not noted in any cases.