Slightly fewer than half of patients had at least one potentially pathogenic bacterium isolated from sputum before starting antibiotic therapy, most often Haemophilus influenzae, Pseudomonas aeruginosa, Streptococcus pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus.
In this subset of patients, the rate of clinical failure was lower with moxifloxacin than with amoxicillin–clavulanic acid in both the intent-to-treat population (19.0% vs. 25.4%; P = .02) and the per-protocol population (19.2% vs. 26.1%; P = .03). Further analysis showed higher rates of bacterial eradication with moxifloxacin, mainly driven by higher rates of eradication of H. influenzae (89.2% vs. 66.7%).
In the study population overall, patients who had bacteriologic eradication at the end of antibiotic therapy, compared with bacteriologic persistence or superinfection, were more likely to be cured 8 weeks later (79.7% vs. 54.7%; P less than .001). The finding was the same in the two treatment groups individually.
The rate of drug-related adverse events was 7.8% with moxifloxacin and 6.1% with amoxicillin–clavulanic acid. The most common events were headache, diarrhea, and fever.
Dr. Sethi reported that he is an investigator for and scientific advisor to Bayer HealthCare Pharmaceuticals, which manufactured the moxifloxacin, and has received speaker honoraria and consulting fees from the company. The trial was supported by Bayer HealthCare Pharmaceuticals.