Aztreonam was administered to 30 patients, ages 0.03 to 15.4 years, with severe and in 21 cases complicated
urinary tract infections caused by members of the family Enterobacteriaceae and Pseudomonas aeruginosa which were resistant to
ampicillin and susceptible to the study
drug in vitro. A mean dose of 47.7 mg/kg was given intramuscularly every 12 h to 26 patients. In four patients with
renal insufficiency, the dose was reduced according to pharmacokinetic data. Permanent urine sterilization and clinical cure were achieved in 22 patients, 13 of whom had urological malformations. In two patients with P. aeruginosa and Proteus mirabilis
infections, the treatment failed. Another patient had an Escherichia coli
reinfection 21 days after the end of
therapy. Four patients with various urological abnormalities had gram-positive
superinfections, and two patients had gram-negative
superinfections during and at the end of
therapy: all six had indwelling ureteric
splints or
pyelostomy as predisposing conditions. No adverse clinical effects were observed. Some transient and slight or moderate alterations were observed at the end of treatment:
eosinophilia (nine cases), elevation of hepatic
enzymes (eight cases), prolongation of prothrombin time (three cases), and
neutropenia (one case). A pharmacokinetic study was performed in six patients with normal renal function and in seven patients with various degrees of
renal insufficiency. The elimination half-life of the
drug was inversely correlated with the glomerular filtration rate. At the dosage used,
aztreonam proved effective for severe
urinary tract infections caused by members of the family Enterobacteriaceae in pediatric patients.