Efficacy and safety of oral ciprofloxacin in the treatment of serious respiratory infections.

Fifty-two patients with serious respiratory infections were treated with orally administered ciprofloxacin; 42 patients were evaluable for the efficacy analysis and all were evaluable for determining adverse reactions. Cures were achieved in 24 patients with infections (14 with bronchitis, 10 with pneumonia) caused by Hemophilus influenzae, Streptococcus pneumoniae, or Branhamella catarrhalis, and pathogens were rapidly eradicated from respiratory secretions. Seventeen patients had infections (seven bronchitis, 10 pneumonia) caused by Enterobacteriaceae or Pseudomonas aeruginosa; many of these patients were critically ill and were enrolled in the study because their pathogens were resistant to multiple drugs or because their infections had not responded to alternate antimicrobial therapy. All patients had favorable clinical responses, and members of the Enterobacteriaceae were rapidly eradicated from respiratory secretions. However, five of 12 strains of P. aeruginosa persisted during treatment; minimal inhibitory concentrations for these strains increased 4- to 16-fold as infections continued to resolve. One patient with Staphylococcus aureus infection also showed a response. Ciprofloxacin probably caused nausea, vomiting, or both in three of the 52 patients and possibly contributed to similar symptoms in another three patients (6 to 12 percent). Other possible adverse reactions, including central nervous system symptoms, were also observed but were not clearly drug-related.