This European multicentre (110 centres), double-blind, randomized clinical trial compared the safety and efficacy of
dirithromycin (500 mg orally once daily) and
erythromycin (250 mg orally qds) in the treatment of either acute bacterial
bronchitis or acute bacterial exacerbations of
chronic bronchitis. From January 1989 to September 1990, 1222 patients (529 with acute
bronchitis and 693 with acute exacerbations of
chronic bronchitis) were included in the trial. Clinical and bacteriological evaluations were performed on 135 evaluable patients with acute
bronchitis (72 in the
dirithromycin group and 63 in the
erythromycin group) and in 202 patients with acute exacerbations of
chronic bronchitis (89 treated with
dirithromycin and 113 treated with
erythromycin). Evaluations were performed during treatment (days 3-5), post-
therapy (three to five days after
therapy completion), and late post-
therapy (10-14 days following the end of
therapy). In acute
bronchitis, both drugs were effective with clinical success rates of 93.0% and 95.2% at post-
therapy, and 96.9% and 100% at late post-
therapy for
dirithromycin and
erythromycin, respectively. Pathogen eradication rates at post-
therapy were 83.3% for the
dirithromycin group and 85.7% for the
erythromycin group. In acute exacerbations of
chronic bronchitis, the drugs were also effective with 89.9% and 92.1% cure or improvement at post-
therapy and 98.7% and 95.0% at late post-
therapy for
dirithromycin and
erythromycin, respectively. Pathogen eradication rates were 75.3% in both treatment groups. There were no statistically significant differences in clinical and bacteriological results between treatments in patients with acute
bronchitis or acute exacerbations of
chronic bronchitis. Of the 1222 patients included, no significant differences in the number of patients reporting adverse events were observed. There were nine early discontinuations due to adverse events in the
dirithromycin group and 14 in the
erythromycin group.
Dirithromycin (500 mg once daily for seven days) was as effective and as safe as
erythromycin (250 mg qid for seven days) in the treatment of acute bacterial
bronchitis and acute bacterial exacerbations of
chronic bronchitis.