Treating acute bacterial exacerbations of chronic bronchitis in patients unresponsive to previous therapy:...

The optimal antibiotic therapy for patients with acute bacterial exacerbations of chronic bronchitis (ABECB) who have failed to respond to previous oral antimicrobial therapy is not known; however, newer macrolide and fluoroquinolone antibiotics may be appropriate. This multicenter, randomized, double-masked, double-dummy study was undertaken to compare the efficacy and tolerability of sparfloxacin with those of clarithromycin in the treatment of ABECB. In 43 centers in the United States, 298 patients (52% male; age range, 19 to 92 years) were randomly allocated to receive a 400-mg loading dose of sparfloxacin, followed by 200 mg once daily, or clarithromycin 500 mg twice daily, for a total of 10 days. Signs and symptoms of ABECB were assessed at each of 4 visits, including a follow-up visit approximately 1 month after the completion of therapy. Efficacy was determined on the basis of the clinical and bacteriologic response rates in the clinically assessable population. Tolerability was assessed on the basis of patient reports, clinical evaluations, and laboratory tests. Of the 266 clinically assessable patients, 109 (85.2%) of 128 patients receiving sparfloxacin and 115 (83.3%) of 138 patients receiving clarithromycin had a clinically successful outcome (cure or improvement). The bacteriologic success rate (eradication of pathogen) was 88.9% (64 of 72 isolates) in the sparfloxacin group and 84.7% (83 of 98 isolates) in the clarithromycin group. Adverse events possibly or probably related to study drug included photosensitivity in 12 (8.3%) and rash in 6 (4.1%) of 145 patients in the sparfloxacin group, and diarrhea in 10 (6.5%), taste perversion in 9 (5.9%), and nausea in 8 (5.2%) of 153 patients in the clarithromycin group. Thus sparfloxacin was as well tolerated and as effective as clarithromycin in the treatment of patients with ABECB unresponsive to previous oral antimicrobial therapy. The overall rate of adverse events was comparable for the 2 study drugs, but the types of events differed.