[Clinical evaluation of ceftriaxone in the treatment of neonatal infections].

Ceftriaxone (CTRX) was administered to the newborn and its clinical effectiveness as well as its blood and cerebrospinal fluid levels were studied. 1. Average blood levels of CTRX 1 hour after single intravenous administration were 39 micrograms/ml in 2 cases receiving about 10 mg/kg, 70 micrograms/ml in 2 other cases receiving 20 mg/kg and 208 micrograms/ml in one receiving 52.6 mg/kg. As is apparent from these cases data, blood levels of CTRX were dose dependent. Blood levels of the drug were between 3.7 to 12.4 micrograms/ml 24 hours later. Half-lives of the drug in blood in the 5 newborns ranged from 7.13 to 10.6 hours. In a 53-day-old patient receiving 43.4 mg/kg of CTRX via intravenous injection, the one-hour blood level of the drug was 140 micrograms/ml and the half-life was 3.68 hours. The blood level of the drug 36 hours after single intravenous administration with 17.3 to 20.0 micrograms/ml to 5 other cases 0 to 5 days of age ranged from 4.6 to 13.7 micrograms/ml. 2. The cerebrospinal fluid level of CTRX 4 hours after intravenous administration with 49.6 mg/kg to cases of Escherichia coli meningitis was 9.7 micrograms/ml on the first day following the start of the treatment. It increased to 23.6, 25.2 and 31.0 micrograms/ml on the third, fourth and fifth days, respectively, and then gradually decreased. Cerebrospinal level was still 5.8 micrograms/ml on the 22nd day during the recovery period. These levels were far more than 1,000 times as much as the MIC for the pathogen at the highest level, and more than 100 times even at the lowest level. 3. CTRX was administered via intravenous injection once or twice a day (11.0-39.5 mg/kg in total) to 13 newborns and 3 infants. The efficacy of CTRX was good to excellent in 10 cases for treatment of 11 diseases (sepsis 1, pneumonia 4, urinary tract infection 4 and fetal infection 2) and all the pathogens (Streptococcus agalactiae 1, E. coli 3, Klebsiella pneumoniae 2, Citrobacter diversus 1) disappeared. In 6 cases where CTRX was used prophylactically, infection did not occur at all. The efficacy was excellent in another newborn with E. coli meningitis intravenously receiving 49.6 mg/kg of CTRX twice daily for 25 days. 4. No adverse reactions were observed. Mild eosinophilia was observed in 4 cases. Follow-up examinations of 3 of the 4 cases showed that these abnormal levels were returned to normal.(ABSTRACT TRUNCATED AT 400 WORDS)