Fundamental and clinical studies of aztreonam in the field of pediatric

: The fundamental and clinical studies of aztreonam (AZT) were performed. The results were as follows: The MICs of AZT for E. coli and Salmonella sp. which were recently isolated in the pediatric field were less than 0.78 micrograms/ml. AZT also was effective against ABPC/PIPC-resistant bacteria. The MIC of AZT for V. parahaemolyticus was less than 1.56 micrograms/ml. The peak serum levels of AZT which were occurred just after the 1 hour drip infusion of 10-30 mg/kg were 60.5-136.8 micrograms/ml, and at 6 hours after infusion the serum levels were 1.3-6.1 micrograms/ml; therefore, the dose response was proved. The mean half-lives (T 1/2) were between 1.21 and 1.36 hours. The excretion rates in urine up to 6 hours after intravenous drip infusion were between 32.7 and 77.5%. The ratio of the cerebrospinal fluid concentration to serum in the child with purulent meningitis was 3.5% at 1 hour after the intravenous injection at the dose of 69 mg/kg, and the ratios of the subdural fluid levels to serum were 31.3-37.5%. The levels of AZT into the feces by the multiple dosage were 0-840 micrograms/g. Twenty-five pediatric patients with acute infections had been treated by intravenous injection or drip infusion at the doses of 49-120 mg/kg/day (almost 50-100 mg/kg/day) for 4 to 13 days. The efficacy rate of excellent + good was 84% and that of excellent + good + fair was 96%. The efficacy rate of excellent + good was 100% in all cases with upper/lower respiratory tract infection, bronchopneumonia, and acute urinary tract infection caused by Gram-negative rods. The clinical efficacy was observed in all cases with acute bacterial enteritis. Although AZT was clinically effective against Salmonella enteritis, bacteriological efficacy on the causative organisms was not observed in some cases. Although AZT was bacteriologically effective in 1 patient with typhoid, it did not alleviated fever. AZT showed activity to 9 strains isolated from the culture of throat swab, urine and feces. No side effects were clinically observed in all cases, while slight elevations of laboratory findings were observed in 4 cases.