Clinical efficacy of ciprofloxacin in patients with respiratory tract infection refractory to penicillin or cephem: Carbapenem-controlled clinical study

Background: Since an injectable new quinolone, ciprofloxacin (CPFX) was approved for clinical use in Japan, it has attracted attention as a new treatment option for infection. The clinical position of CPFX has yet to be established, however. Objectives: To clarify the clinical position of CPFX in the treatment of respiratory tract infection. Patients and Methods: Patients with pneumonia or exacerbated chronic respiratory tract infection refractory to penicillin or cephem antibacterial agents were randomized to be administered CPFX by intravenous infusion (300 mg bid) or carbapenem by intravenous infusion (0.3-0.5 g bid), and the efficacy, safety, duration of hospitalization, and duration of antibacterial therapy were compared between groups. Results: Among 83 patients enrolled in the study. 78 complying with the protocol were evaluated for safety (safety analysis set) and 68 for efficacy (efficacy analysis set) . The two groups were similar in age, gender ratio, infection diagnosis and severity, and prior antibacterial therapy. Efficacy was comparable between groups, at 82.7% (24/29 patients) in the CPFX group and 71.0% (22/31 patients) in the carbapenem group. The number of patients who improved early and could cease treatment with the study drug was greater in the CPFX group (p <0.05). No significant difference was noted between groups in duration of hospitalization or duration of therapy. The incidence of adverse drug reactions (adverse events for which a causal relationship to the study drug could not be ruled out) was 13.5% (5/37 patients) in the CPFX group and 12.2% (5/41 patients) in the carbapenem group, and none in either group experienced serious adverse reactions. Discussion: In patients with respiratory tract infection refractory to penicillin or cephem antibiotics, CPFX showed at least comparable clinical efficacy to that of carbapenem and achieved a higher early improvement rate. These results suggest that CPFX is a viable option for the treatment of respiratory tract infection.