A double-blind study of two dosage regimens of lomefloxacin in bacteriologically proven exacerbations of chronic bronchitis of gram-negative etiology.

Lomefloxacin has been shown to produce high and sustained concentrations in serum and bronchial mucosa after once-daily administration. This study was designed to assess whether a dose response exists for 400 mg lomefloxacin given once daily or twice daily for 10 days in the treatment of acute bacterial exacerbations of chronic bronchitis of gram-negative etiology. A total of 100 adult patients with acute exacerbations of chronic bronchitis were enrolled at 10 study sites in Germany. Patients with confirmed bacterial pathogens in the baseline sputum culture (once-daily group n = 49, twice-daily group n = 47) were eligible for analysis of bacteriologic and clinical efficacy. The eradication rates for the most frequently isolated baseline pathogens, Haemophilus influenzae, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were at least 75% for both treatment regimens. Overall, once-daily treatment eradicated baseline pathogens in 42 of 49 (85.7%) patients, while twice-daily treatment eradicated pathogens in 43 of 47 (91.5%). This difference was not statistically significant (p = 0.226). Clinically, 47 of 49 (95.9%) patients in the once-daily group and 46 of 47 (97.9%) in the twice-daily group were cured or improved (p = 0.307). Both regimens were well tolerated; there were no differences in the incidence (six patients in each group), types, or severity of adverse events, nor was there clinical evidence of theophylline interaction. The results of this study demonstrate that once-daily treatment with 400 mg lomefloxacin is as effective as twice-daily dosing with 400 mg in patients with acute bacterial exacerbations of chronic bronchitis.