Summary of worldwide clinical trials of aztreonam in patients with urinary tract infections.

Aztreonam was administered to a total of 681 patients with urinary tract infections due to susceptible gram-negative bacteria; 56 patients received a single 1-g intramuscular dose for acute uncomplicated cystitis, and 625 patients received multiple parenteral doses (usually a five-day course of 1 g two or three times daily) for a variety of urinary tract infections, including pyelonephritis, cystitis, prostatitis, and epididymitis. Microbiologic cure was achieved in 84% of patients in the single-dose study and in 85% of patients in the multiple-dose studies. In the latter studies the microbiologic cure rates for infections with Escherichia coli, the Klebsiella-Enterobacter-Serratia group, and Pseudomonas aeruginosa were 87%, 90%, and 76%, respectively. In a comparative study of aztreonam and cefamandole, the overall microbiologic cure rates were 89% and 80%, respectively. Of the 625 patients receiving multiple-dose therapy, 149 had urinary tract infections due to multiply drug-resistant bacteria; among these patients the microbiologic cure rate was 93%. Aztreonam constitutes effective therapy for urinary tract infections due to susceptible gram-negative bacilli.