[Clinical and pharmacokinetic evaluation of aztreonam in neonates]

Nine neonates were treated with aztreonam (AZT) and its clinical efficacy and side effects were evaluated. Six of the patients were treated with a combination of AZT and ampicillin. Ages of the patients ranged from 0 to 24 days, and their body weights ranged from 2,290 to 4,260 g. Doses of AZT ranged 18.8 to 23.7 mg/kg every 8 to 12 hours for 3 to 7 days. Three patients with infections including urinary tract infection, cervical abscess, and suspicion of sepsis, appeared to respond to the treatment of AZT alone. Among them, clinical results were excellent in 1, good in 2 patients. Those patients subjected to the combination therapy showed excellent response in 1 and good in 5. The drug was well tolerated, but 1 had diarrhea. The pharmacokinetics of AZT was studied in 9 patients. Their ages ranged from 0 to 30 days, and body weights ranged from 2,000 to 4,000 g. Serum concentrations of AZT were 27.2 to 48.3 micrograms/ml at 1 hour after single 20 mg/kg intravenous bolus injection, and the levels were 3.4 to 15.5 micrograms/ml at 6 hours in 5 infants heavier than 2,500 g. Elimination half-lives of AZT ranged from 1.57 to 3.72 hours (mean 2.72 hours). Serum concentrations of AZT were 21.6 to 41.8 micrograms/ml at 1 hour after single 20 mg/kg intravenous bolus injection, and the levels were 10.2 to 17.0 micrograms/ml at 6 hours in 3 infants lighter than 2,500 g. The elimination half-lives of AZT were 3.63 to 4.86 hours (mean 4.31 hours).(ABSTRACT TRUNCATED AT 250 WORDS)