Efficacy of 750-mg, 5-day levofloxacin in the treatment of community-acquired pneumonia caused by atypical pathogens

Background: Current recommended durations for treatment of atypical community-acquired pneumonia (CAP) range from 10 to 21 days. However, antibiotics such as the fluoroquinolones may allow for effective, short-course regimens. Objective:This study evaluated the efficacy of 750 mg levofloxacin for 5 days compared to a 500-mg, 10-day levofloxacin regimen for the treatment of atypical CAP. Methods: A randomized, active -controlled, double-blind, multicenter study was conducted within the United States. Of the 528 patients enrolled in the study, 149 were diagnosed with CAP due to Legionella pneumophila, Chlamydia pneumoniae, or Mycoplasma pneumoniae. Patients' baseline symptoms were re-evaluated on Day 3 of therapy. Clinical efficacy and resolution of CAP symptoms were evaluated at the posttherapy visit (7-14 days after the last dose of active drug). Results:This report represents a subgroup analysis of a previous clinical study. Among the 123 clinically evaluable patients diagnosed with atypical CAP (26 patients were unevaluable), the clinical success rates were 95.5% (63 of 66 patients) for the 750-mg group and 96.5% (55 of 57 patients) for the 500-mg group (95% CI for success rate of the 500-mg group minus that of the 750-mg group, -6.8 to 8.8). At the poststudy evaluation (31-38 days after treatment began), relapse occurred in less than or equal to 2% of patients in either treatment group. Among patients diagnosed with atypical CAP, the 750-mg therapy resulted in more rapid symptom resolution, with a significantly greater proportion of patients experiencing resolution of fever by Day 3 of therapy (p = 0.031). Conclusion: The 750-mg, 5-day course of levofloxacin was at least as effective as the 500mg, 10-day regimen for atypical CAP. Additionally, the 750-mg, short-course levofloxacin therapy may reduce total antimicrobial drug usage and more rapidly relieve pneumonia symptoms.