Double-blind, dose-range-finding study of fleroxacin (RO 23-6240; AM-833) for treatment of complicated urinary tract infections

In a double-blind randomized trial, we evaluated the efficacy and safety of three oral dosage regimens of fleroxacin, a new fluoroquinolone, once daily in 62 patients for the treatment of complicated urinary tract infections. The regimens compared were 200 mg for 10 days (n = 20), 400 mg for 10 days (n = 21), and 600 mg for 10 days (n = 21). Forty-five patients were evaluable for efficacy. A clinical cure was reached in 78% of the patients. Overall, a favorable bacteriological response (negative culture or reinfection at 4 to 6 weeks) was obtained in 36 of 45 (80%) patients. No significant difference could be found among the three dosage groups. During therapy, one Klebsiella ozaenae strain became resistant and one Pseudomonas aeruginosa strain became less susceptible to fleroxacin. In 13 patients, therapy had to be discontinued due to major adverse events (oliguria [n = 1], psychosis [n = 1], photosensitivity [n = 1], insomnia [n = 1], and nausea [n = 9]). Minor side effects were seen in 13 other patients. Increased dosage correlated significantly (P < 0.01) with total number of adverse events.