Clinical perspectives on new antimicrobials: focus on fluoroquinolones

Respiratory tract infections are the most common infectious presentation in the community and hospital settings and are a major cause of morbidity and mortality worldwide. Recently, newer fluoroquinolones have been recommended for the treatment of these infections. Among them, moxifloxacin shows improved activity against gram-positive pathogens, has maintained potency against gram-negative organisms, and shows activity against atypical pathogens and anaerobes. Moxifloxacin also has excellent in vitro activity against strains resistant to penicillin, erythromycin, and other fluoroquinolones, such as levofloxacin. Moxifloxacin has demonstrated clinical efficacy rates of 90%-95% in clinical trials in community-acquired pneumonia, acute exacerbations of chronic bronchitis, and acute sinusitis. In these trials, moxifloxacin demonstrated no serious or unexpected adverse effects. Development of resistance appears to be slower for moxifloxacin than for several other fluoroquinolones, making moxifloxacin a good treatment choice. The pharmacodynamics of moxifloxacin support once-daily oral therapy of short duration, providing convenience, compliance, and safety advantages.