Comparative efficacy of ciprofloxacin, azlocillin, and tobramycin alone and in combination in experimental Pseudomonas sepsis.

Ciprofloxacin, azlocillin, and tobramycin, used alone and in combination, were studied in a model of lethal pseudomonas sepsis in rats. Ciprofloxacin alone at all doses studied and tobramycin alone at the highest dose reduced mortality significantly compared with saline controls. In contrast, survival was not improved with either azlocillin alone at all doses studied or lower doses of tobramycin alone. The combination of ciprofloxacin and azlocillin was synergistic in rats with systemic pseudomonas infection. Ciprofloxacin was rapidly absorbed, and effective levels persisted for 1-4 hr relative to the dose administered. These data suggest that ciprofloxacin may be a potent agent, either alone or in combination with azlocillin, in the treatment of severe pseudomonas infections.