Efficacy of fleroxacin versus amoxicillin in acute exacerbations of chronic bronchitis.

In a multicenter study the efficacy and safety of oral fleroxacin at 400 mg once a day and amoxicillin at 500 mg three times daily for 7 days were compared for the treatment of patients with acute bacterial exacerbations of chronic bronchitis due to drug-susceptible bacteria. A total of 194 patients were enrolled, 102 in the fleroxacin group and 92 in the amoxicillin group. Of those enrolled, 22 in the fleroxacin group and 30 (29 for clinical efficacy) in the amoxicillin group were included in the efficacy analysis. All were included in the safety analysis. Clinical success was noted in 21 (95%) of 22 fleroxacin-treated patients and 22 (76%) of 29 amoxicillin-treated patients. Bacteriologic cure was obtained in 21 (95%) of 22 of the fleroxacin group and 18 (60%) of 30 of the amoxicillin group. One Haemophilus parainfluenzae strain persisted with fleroxacin. Persisting organisms with amoxicillin included Haemophilus influenzae (four), Haemophilus parainfluenzae (three), Escherichia coli (two), Streptococcus pneumoniae (one), Neisseria species (one), and Proteus mirabilis (one). Adverse events were reported by 41% of 102 patients receiving fleroxacin and 15% of 92 patients receiving amoxicillin. Insomnia, dizziness, and nausea occurred more frequently with fleroxacin. Fleroxacin may be indicated for the treatment of acute bacterial infection in chronic bronchitis known to be due to Haemophilus species and Moraxella catarrhalis. The 92% incidence of resistance among the S. pneumoniae isolates recovered from all enrolled patients suggests that fleroxacin may not be useful for such infections.