Treating acute bacterial exacerbations of chronic bronchitis in patients unresponsive to previous therapy: Sparfloxacin versus clarithromycin

The optimal antibiotic therapy for patients with acute bacterial exacerbati ons of chronic bronchitis (ABECB) who have failed to respond to previous or al antimicrobial therapy is not known; however, newer macrolide and fluoroq uinolone antibiotics may be appropriate. This multicenter, randomized, doub le-masked, double-dummy study was undertaken to compare the efficacy and to lerability of sparfloxacin with those of clarithromycin in the treatment of ABECB. In 43 centers in the United States, 298 patients (52% male; age ran ge, 19 to 92 years) were randomly allocated to receive a 400-mg loading dos e 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 asses sed 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 th e clinical and bacteriologic response rates in the clinically assessable po pulation. Tolerability was assessed on the basis of patient reports, clinic al evaluations, and laboratory tests. Of the 266 clinically assessable pati ents, 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 patho gen) 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 pro bably 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 patient s in the clarithromycin group. Thus sparfloxacin was as well tolerated and as effective as clarithromycin in the treatment of patients with ABECB unre sponsive to previous oral antimicrobial therapy. The overall rate of advers e events was comparable for the 2 study drugs, but the types of events diff ered.