tetracycline and difloxacin

Difloxacin is a new quinolone antimicrobial agent with in vitro activity against both Neisseria gonorrhoeae and Chlamydia trachomatis and a long (26-h) half-life. A single oral dose of 200 mg of difloxacin was used to treat 30 men with uncomplicated urethral gonorrhea in an open trial. Of the isolates of N. gonorrhoeae, three produced penicillinase and two were resistant to tetracycline. N. gonorrhoeae was eradicated from all 29 evaluable patients. The geometric mean MIC of difloxacin for 30 pretreatment N. gonorrhoeae isolates was 0.014 (range, less than or equal to 0.0039 to 0.03) microgram/ml. Four (13.3%) of the 30 subjects with gonococcal urethritis also had C. trachomatis recovered from their pretreatment cultures. Treatment with difloxacin was associated with the eradication of C. trachomatis from all four men. In addition, C. trachomatis was isolated from the posttreatment culture of only one man who had a negative culture before treatment. Nineteen patients (65.5%) reported adverse experiences, and 17 of them (58.6%) developed symptoms suggestive of central nervous system dysfunction. An oral dose of 200 mg of difloxacin is effective treatment for uncomplicated urethral gonorrhea and may also eliminate a coexisting infection with C. trachomatis. Side effects may limit the utility of this agent.

Topics: Adult; Anti-Bacterial Agents; Chlamydia Infections; Ciprofloxacin; Clinical Trials as Topic; Fluoroquinolones; Gonorrhea; Humans; Male; Microbial Sensitivity Tests; Neisseria gonorrhoeae; Penicillin G; Tetracycline

The in vitro activity of tetracycline, ciprofloxacin and two recently developed 1-aryl-fluoroquinolones, A56610 and A56620, was tested against 65 beta-lactamase-negative and 35 beta-lactamase-positive Neisseria gonorrhoeae strains, 12 Chlamydia trachomatis, 50 Mycoplasma hominis, 28 Ureaplasma urealyticum and 50 Gardnerella vaginalis strains. In the case of Chlamydia trachomatis and Mycoplasma hominis both the MIC and the MBC were determined. The MIC90 of ciprofloxacin for Neisseria gonorrhoeae was 0.008 microgram/ml and of A56619 and A56620 less than or equal to 0.03 microgram/ml. No difference was observed between the activity against beta-lactamase-negative and beta-lactamase-positive strains. The MIC90 values of of ciprofloxacin and A56620 for Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum were identical, the values being 2 micrograms/ml, 1 micrograms/ml and 4 micrograms/ml respectively. The MIC90 of A56619 for Chlamydia trachomatis and Ureaplasma urealyticum was 0.5 micrograms/ml and 1 microgram/ml respectively. The MBC90 values of the three quinolones for Chlamydia trachomatis and Mycoplasma hominis were less than or equal to 2 micrograms/ml. The activity of the quinolones against Gardnerella vaginalis was rather low, the MIC90 being greater than or equal to 4 micrograms/ml. It is concluded that A56619 and A56620 might be useful for single-dose therapy of gonococcal infections.

Topics: Anti-Bacterial Agents; Bacteria; Chlamydia trachomatis; Ciprofloxacin; Fluoroquinolones; Gardnerella vaginalis; Humans; Microbial Sensitivity Tests; Mycoplasma; Neisseria gonorrhoeae; Tetracycline; Ureaplasma