CLINICAL THERAPEUTICSVVOL. 21, NO. 6, 1999 Treating Acute Bacterial Exacerbations of Chronic Bronchitis in Patients Unresponsive to Previous Therapy: Sparfloxacin Versus Clarithromycin Benjamin A. Lipsky, MD,’ Joel Unowsky, PhD,2 Hao Zhang, PhD,2 Lloyd Townsend, MD, PhD,2 and George H. Talbot, Mti ‘University of Washington School of Medicine, and Medical Service, VA Puget Sound Health Care System, Seattle, Washington, and 2RhSne-Poulenc Rorer Pharmaceuticals, Inc., Collegeville, Pennsylvania ABSTRACT The optimal antibiotic therapy for patients with acute bacterial exacerbations of chronic bronchitis (ABECB) who have failed to respond to previous oral antimi- crobial therapy is not known; however, newer macrolide and fluoroquinolone an- tibiotics may be appropriate. This multicen- ter, randomized, double-masked, double- dummy study was undertaken to compare the efficacy and tolerability of sparfloxacin with those of clarithromycin in the treat- ment 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 spar- floxacin, followed by 200 mg once daily, or clarithromycin 500 mg twice daily, for a to- tal of 10 days. Signs and symptoms of ABECB were assessedat each of 4 visits, including a follow-up visit approximately 1 Accepted for publication March 10, 1999. Printed in the USA. Reproduction in whole or part is not permitted. month after the completion of therapy. Ef- ficacy was determined on the basis of the clinical and bacteriologic response rates in the clinically assessablepopulation. Toler- ability was assessed on the basis of patient reports, clinical evaluations, and laboratory tests. Of the 266 clinically assessable pa- tients, 109 (85.2%) of 128 patients receiv- ing sparfloxacin and 115 (83.3%) of 138 patients receiving clarithromycin had a clin- ically successful outcome (cure or im- provement). The bacteriologic successrate (eradication of pathogen) was 88.9% (64 of 72 isolates) in the sparlloxacin group and 84.7% (83 of 98 isolates) in the clarithro- mycin 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 per- version 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 treat- ment of patients with ABECB unrespon- sive to previous oral antimicrobial therapy. 954 0149-2918/99/$19.00