Quinolones are currently used as empirical
therapy for treatment of community-acquired lower
respiratory infections as they are effective against a broad range of conventional bacterial and 'atypical' pathogens, including Chlamydia pneumoniae. C. pneumoniae is estimated to be associated with 10-20% of community-acquired
pneumonia in adults, and has recently been suggested to play a role in several non-respiratory conditions, including
atherosclerosis. The newer, third-generation
quinolones have enhanced activity against Gram-positive bacteria, including Streptococcus pneumoniae, and prolonged serum half-lives that permit once-daily dosing. Although
gemifloxacin (SB-265805) and other new
quinolones have good activity against C. pneumoniae in vitro, practically all published treatment studies have relied on serological diagnosis. Consequently, the microbiological efficacy of these agents in human
infection has not been assessed. This paper reviews what is known to date of the in vivo microbiological efficacy of the
quinolones against C. pneumoniae, and demonstrates the importance of assessing this parameter when evaluating the clinical utility of these agents in C. pneumoniae
infection.