Comparison of 5-day, short-course gatifloxacin therapy with 7-day gatifloxacin therapy and 10-day clarithromycin therapy for acute exacerbation of chronic bronchitis

Background: The ideal duration of antibiotic therapy for acute exacerbation of chronic bronchitis (AECB) remains controversial. Objective: This study compared short-course, 5-day gatifloxacin treatment with standard 10-day cl arithromycin treatment in patients with AECB; 7-day gatifloxacin therapy wa s a secondary comparator. Methods: This was a multicenter, prospective, randomized, double-blind stud y in which adult outpatients with AECB were randomized to 1 of 3 treatment groups: 5 days of gatifloxacin, 7 days of gatifloxacin, or 10 days of clari thromycin. Clinical cure and microbiologic eradication rates were determine d 7 to 14 days after the completion of antibiotic treatment. Results: A total of 527 patients with AECB were enrolled and treated with s tudy drug (174, gatifloxacin 5-day; 175, gatifloxacin 7-day; 178, clarithro mycin 10-day). Most patients (82%) had type 1 (severe) exacerbations, and a bacterial pathogen was isolated from pretreatment sputum samples in 59% of patients. The overall clinical cure rates among clinically evaluable patie nts were comparable between groups. 89% (135/151 patients) in the gatifloxa cin 5-day group; 88% (136/154) in the gatifloxacin 7-day group; and 89% (14 5/163) in the clarithromycin 10-day group. The 95% CIs for the differences in response rates were -6.1 to 7.0 for gatifloxacin 5-day versus clarithrom ycin, -8.9 to 5.0 for gatifloxacin 7-day versus clarithromycin, and -5.5 to 8.0 for gatifloxacin 5-day versus 7 day. These observations did not appear to be affected by use of corticosteroids or smoking status, type of exacer bation, or duration of current episode. The microbiologic eradication rate among microbiologically evaluable pathogens was >90% in all treatment group s. No clinically meaningful differences were noted in the incidence of drug -related adverse events. Conclusion: Short-course, 5-day gatifloxacin therapy in patients with AECB resulted in clinical cure and microbiologic eradication rates comparable to those of standard 7- and 10-day therapies.