Efficacy and tolerability of once-daily grepafloxacin compared with clarithromycin in the treatment of acute bacterial exacerbations of chronic bronchitis

Objectives: The clinical and bacteriological efficacies and tolerability of grepafloxacin 400mg once daily for 10 days were compared with clarithromycin 500mg twice daily for 10 days in patients with acute bacterial exacerbations of chronic bronchitis (ABECB). Patients and Study Design: 379 patients with signs and symptoms of ABECB were enrolled in a randomised, double-blind clinical trial conducted at 15 outpatient centres in the USA. Eligible patients were randomly assigned to receive either grepafloxacin plus matched clarithromycin placebo (n = 187) or clarithromycin plus matched grepafloxacin placebo (n = 192). Results: The two treatment groups were equivalent with respect to clinical efficacy, and no statistically significant differences in the incidence of drug-related adverse events were seen between the two groups. A satisfactory clinical outcome was achieved in 89% (134 of 150) and 88% (130 of 148) of clinically evaluable patients treated with grepafloxacin or clarithromycin, respectively. The primary pathogens isolated from pretreatment sputum specimens were Haemophilus parainfluenzae, H. influenzae, Moraxella catarrhalis, Streptococcus pneumoniae and Staphylococcus aureus (31, 18, 6, 5 and 4% of isolates, respectively). Pathogens were eradicated or presumed to be eradicated in 78% (97 of 125) and 88% (113 of 129) of bacteriologically evaluable patients treated with grepafloxacin or clarithromycin, respectively. Both treatments were associated with a low incidence of drug-related adverse events. Conclusion: These results indicate that grepafloxacin 400mg once daily for 10 days is as well tolerated and as clinically effective as clarithromycin 500mg twice daily for 10 days in patients with ABECB.