Fluoroquinolones vs macrolides in the treatment of Legionnaires disease

Background: Erythromycin has been the treatment of choice for Legionnaires disease (LD). However, treatment failure and experimental evidence of its bacteriostatic effect have led to evaluation of new drugs such as fluoroquinolones. This study compared the evolution of patients with LD treated with macrolides and fluoroquinolones. Methods: A prospective observational study was performed, and 130 patients from three centers were included. Diagnoses were made using Legionella urinary antigen assay in all patients. Patients receiving any antibiotic > 36 h before starting the study therapy were excluded. Group 1 included 76 patients who received macrolides (33 patients with erythromycin and 43 patients with clarithromycin), and group 2 included 54 patients treated with fluoroquinolones (50 patients with levofloxacin and 4 patients with ofloxacin). Results: No significant differences were seen between the two groups regarding age, sex, smoking, alcohol intake, underlying diseases, or community/hospital acquisition. The time from onset of LD symptoms until the initiation of antibiotic treatment was 78.5 h and 92.7 h in groups 1 and 2, respectively (p = 0.1). Time to apyrexia was significantly longer in the macrolide group (77.1 h vs 48 h for groups 1 and 2, respectively; p = 0.000). There were no differences according to radiology, clinical complications, or mortality. Nevertheless, a trend to a longer hospital stay was observed in the macrolide group (9.9 days vs 7.6 days in groups 1 and 2, respectively; p = 0.09). Conclusions: Fluoroquinolones were as effective as erythromycin in the treatment of LD. It is of note that time to apyrexia was significantly shorter and hospital stay tended to be shorter in patients receiving fluoroquinolones.