Evaluation of the clinical microbiology profile of moxifloxacin

Moxifloxacin is a new broad-spectrum antibacterial agent for treatment of respiratory tract infection of pathogens, including the major pathogens isolated in respiratory tract infections. The pharmacokinetic and pharmacodynamic properties of moxifloxacin are: excellent bioavailability, long half-life, and superior tissue penetration. Consequently, the 90% minimum inhibitory concentration (MIC(90)) values exhibited by moxifloxacin are generally lower than the concentrations of moxifloxacin found in circulation and in pulmonary tissues after a standard 400-mg dose given for up to 30 h. The relationship between moxifloxacin MIC(90) values and clinical response was investigated. The results of 13 clinical trials, performed in 30 countries between 1997 and 1998 and comprising 2618 patients treated with moxifloxacin or a comparator drug, were reviewed. Overall, 94% clinical success and 95% bacterial eradication was observed with moxifloxacin. These results were equivalent or superior to results seen with the comparator drugs. Clinical response rates and bacterial eradication rates with moxifloxacin were not significantly affected by bacterial resistance to other antibiotics (i.e., penicillin, clarithromycin, or amoxicillin). The majority (89%-97%) of the different bacterial strains with MICs for moxifloxacin < or =2 mg/L were successfully eradicated. In conclusion, moxifloxacin has potent in vivo bactericidal activity, and pathogen sensitivity to moxifloxacin is in accordance with US Food and Drug Administration and European suggested breakpoint values.