Clarithromycin versus cefaclor for the treatment of mild-to-moderate acute bacterial bronchitis.

Four hundred and eight outpatients with the clinical signs and symptoms of mild-to-moderate acute bronchitis of bacterial aetiology were enrolled in a multicentre, double-blind, randomized clinical trial comparing the efficacy and safety of clarithromycin and cefaclor, both administered orally. Two hundred and seven patients received clarithromycin 250 mg bd and 201 patients received cefaclor 500 mg tds for a maximum of seven days. Clinical and bacteriological evaluations were performed before treatment was initiated, during the course of treatment, and within 72 h of completing therapy; all adverse events were recorded. Two hundred and three patients in the clarithromycin group and 195 in the cefaclor group were evaluable for clinical response and 129 and 124 patients in the clarithromycin and cefaclor groups, respectively, were evaluable for bacteriological response. The clinical response rates three to five days after starting treatment and at the post-treatment assessment were 97% (193/199) and 99.5% (202/203), respectively, for the clarithromycin group and 97.4% (187/192) and 97.9% (191/195), respectively, for the cefaclor group. The bacteriological cure rates were 94.6% (122/129) for the clarithromycin group and 90.3% (112/124) for the cefaclor group. None of the differences between the groups was statistically significant. Adverse events, which were generally mild and predominantly related to the gastrointestinal tract, were reported by 5.8% of clarithromycin-treated patients and 10.4% of cefaclor-treated patients. Adverse reactions caused one patient in the clarithromycin group and three in the cefaclor group to discontinue treatment prematurely. The results of this study indicate that clarithromycin and cefaclor are comparable with respect to efficacy and safety when used as treatment for patients with mild-to-moderate acute bacterial bronchitis.