Adult respiratory tract Infections: Single Dose Azithromycin vs. 3-day Azithromycin vs. Clarithromycin in the Treatment of Atypical Community-Acquired Pneumoniae in Adults

The aim of this open, comparative, randomized study was to compare the efficacy and safety of a single 1.5 g dose of azithromycin with standard 3-day azithromycin regimen and with 10-day course of clarithromycin in the treatment of communitiy-acquired pneumonia. A total of 178 adult patients of both sexes with a new pulmonary infiltrate on chest radiograph, and some of the following sings and symptoms of pneumonia: chest pain, cough, positive auscultatory finding of fever (38°C) who gave their written informed consent, were randomized to receive either 1, 5 g of azithromycin as a single dose, or 500 mg once daily for 3 days, or 250 mg clarithromycin twice-daily for 10 days. Causative pathogens were identified by blood and/or sputum cultures as well as by serologic testing of antibodies directed to Mycoplasma pneumoniae, Chlamydia pneumoniae, C.psittaci, Coxiella burnetii, and urinary antigen test for legionella pneumophila. Control clinical examinations were performed 2, 3, 10-14 days and 4-5 weeks after treatment initiation. Cure was defined as disappearance of sings and symptoms of pneumonia with regression of infiltrate on chest radiograph within 10-14 days after treatment initiation and with no relapse of disease during the follow-up period. Treatment groups were comparable with respect to demographic and anamnestic data. Among 177 patients who were evaluable for clinical efficacy, most common causative pathogen were M.pneumoniae (in 98 patients) and C.pneumoniae (in 15 patients). Cure were recorded in all patients in the single dose azithromycin group, in 98.3% of patients in the 3-day azithromycin group and in 98.3% of patients in the clarithromycin group. Adverse events were in 9 patients in the single dose azithromycin group, 10 in 3-day azithromycin group, and 13 in the clarithromycin group. The results of this study showed that single 1.5 g dose of azithromycin was equally effective and well tolerated as standard 3-day azithromycin or 10-day clarithromycin course in the treatment of communitiy-acquired pneumoniae in adult patients