Materno-fetal transfer of azlocillin

We studied 20 patients to assess transfer of azlocillin to the fetus at parturition. The elimination half-life of approximately 1.3 h in these mothers was similar to that reported for normal subjects. Azlocillin quickly reached umbilical cord blood, amniotic fluid, the placenta and the urine of the neonate, achieving substantial concentrations. Azlocillin then disappeared from umbilical cord blood with an elimination half-life of 2.3 h, i.e., similar to that of the mother. At 6 h, concentrations of azlocillin were still increasing in amniotic fluid and placenta. In addition, in two stillborn infants, azlocillin was found to reach substantial concentrations in all tissues analysed except brain. Concentrations of azlocillin achieved in fetal tissues are sufficient to have important therapeutic effects. © 1983 The British Society for Antimicrobial Chemotherapy

Ceftriaxone distribution between maternal blood and fetal blood and tissues at parturition and between blood and milk postpartum

The penetration of ceftriaxone into the fetus at parturition was studied in 17 subjects. Despite its high protein binding, ceftriaxone quickly reached the umbilical cord blood, amniotic fluid, and placenta, achieving substantial concentrations, which then disappeared, with elimination half-lives of approximately 6 h, identical to that of the mother. The elimination half-life of ceftriaxone of 5 to 6 h in these mothers was somewhat shorter than that reported for normal subjects. The concentrations of ceftriaxone achieved in fetal tissues were sufficient for therapeutic effects. The penetration of ceftriaxone into milk was studied 3 days postpartum in 20 other patients. This antimicrobial agent entered breast milk rapidly and disappeared with a half-life of 12 to 17 h. The concentrations achieved were only 3 to 4% of those in maternal serum and were most likely of little clinical relevance

Clinical pharmacology of cefotaxime in pediatric patients

Cefotaxime is a new cephalosporin with a spectrum of activity which may make it appropriate for use in pediatric patients. In 33 infants and children, administration of cefotaxime resulted in cure or improvement in 97% of patients, with eradication of 94% of isolated pathogens. Toxicity was minimal. The disposition of cefotaxime in this age group was similar to that reported for adults, with an elimination half-life approximately 1.5 h, a volume of distribution of 1 liter/kg, a total serum clearance of 10 ml/min per kg, and a renal clearance of 6 ml/min per kg

Treatment of severe neonatal infections with cefotaxime. Efficacy and pharmacokinetics

We studied the pharamcokinetics and efficacy of cefotaxime in 32 neonates with severe gram-negative infections. Many of these patients had been treated unsuccessfully with combinations of antibiotics. Eighty-one percent of these were cured, 6% improved, and 13% had treatment failures; there were three deaths. Eighteen patients received cefotaxime alone; 16 were cured and two improved. These data indiate and efficacy of cefotaxime sufficient to warrant more rigorous future trials. The elimination half-life of cefotaxime ranged from 2.0±0.4 hours in term neonates more than one week of age to 5.7±0.8 hours in preterm neonates less than one week of age. A volume of distribution of approximately 0.63 L was similar for all infants irrespective of age and maturity. These kinetic data can be used in design of future therapeutic regimens in more rigidly controlled trials assessing indications for cefotaxime therapy in neonates. We recommend dosing as follows, using a dose of 25 mg/kg: every 12 hours for preterm infants less than one week of age, every 8 hours for pretern infants one to four and term nfants less than one week of age, and every 6 hours for term infants more than one week of age. © 1982 The C. V. Mosby Company