This randomized, multicentre, double-blind, double-dummy study compared the efficacy and safety of
amoxycillin 1 g bd with
amoxycillin 500 mg
tds in 395 patients with a clinical diagnosis of acute exacerbation of
chronic bronchitis (AECB). Patients were treated for 10 days and were assessed during
therapy (days 3-5), after the end of
therapy (days 12-15) and at follow up (days 28-35). In the intention-to-treat (ITT) population, clinical success rates at the end of
therapy were 86.6% (162/187 patients) and 85.6% (161/188 patients) in the bd and
tds group, respectively. In the per-protocol (PP) subgroup, the success rates were 89.1% (156/175) and 92.6% (150/162), respectively. The clinical recurrence rates at follow up were, in the ITT and PP populations, respectively, 14.2% (20/141) and 13.4% (18/134) in the bd group, and 12.6% (18/143) and 13.7% (18/131) in the
tds group. The 95% confidence intervals (CI) confirmed the clinical equivalence of the two dosage regimens in the ITT and PP populations. Two hundred and nineteen patients from the clinically evaluable ITT population had at least one pathogen isolated at baseline and were evaluable for bacteriological efficacy. Bacteriological success at the end of
therapy was obtained in 76.2% (83/109) of patients in the bd group, and 73.7% (81/110) of patients in the
tds group (95% CI: -9 to 14%). The most frequently reported
drug-related adverse events in the safety evaluable patients were gastrointestinal symptoms, which occurred in 11.2% (22/197) in the bd group and 11.6% (23/198) in the
tds group.
Amoxycillin 1 g bd is clinically and bacteriologically as effective as
amoxycillin 500 mg
tds in the treatment of AECB, and the two dosage regimens show a similar safety profile.