Single-dose pharmacokinetics of aztreonam in pediatric patients

Single intravenous doses (30 mg/kg) of aztreonam, a novel monobactam antibiotic, were administered to 29 children from 2 days to 11 years old. Serum, urine, and, when possible, cerebrospinal fluid samples were analyzed by high-pressure liquid chromatography and microbiological methods. The concentration of aztreonam in serum 15 min after drug administration was approximately 100 micrograms/ml in all age groups. The elimination half-life varied inversely, and the clearance from serum varied directly, with age. Aztreonam pharmacokinetics in 2- to 12-year-olds were similar to those in adults. The concentration in urine was high and prolonged, with potentially therapeutic concentrations still present 12 to 24 h after infusion in all age groups. Penetration into cerebrospinal fluid averaged 17.3% in children with inflamed meninges. Standard clinical and laboratory measurements revealed no untoward reactions. The 30-mg/kg dose of aztreonam produced potentially therapeutic concentrations in serum, urine, and cerebrospinal fluid. A dosage schedule of every 6 to 8 h in older children and every 8 to 12 h in neonates is suggested for multiple-dose clinical trials.