title: In vitro activities of azithromycin, clarithromycin, L-ofloxacin, and other antibiotics against Chlamydia pneumoniae.
abstract: The in vitro susceptibilities of 11 strains of Chlamydia pneumoniae to azithromycin, clarithromycin, erythromycin, L-oflaxacin, and doxycycline were determined. Clarithromycin was the most active agent tested, with an MIC for 90% of strains and minimal chlamydiacidal concentration for 90% of strains of 0.03 microns/ml. The activity of azithromycin was similar to those of erythromycin and doxycycline, with MICs for 90% of strains of 0.125 to 0.25 microns/ml. However, the prolonged half-life and enhanced tissue penetration of azithromycin should allow for less frequent dosing and shorter duration of therapy than with erythromycin or clarithromycin. L-Ofloxacin had activity similar to that of ofloxacin, with MICs of 0.125 to 0.5 micron/ml. From the results of this in vitro study, azithromycin and clarithromycin appear to be effective antibiotics that may have a role in the treatment of infections due to C. pneumoniae.
authors.affiliation: Department of Pediatrics and Medicine, State University of New York, Brooklyn 11203.
authors.forename: M R
authors.initials: MR
authors.lastname: Hammerschlag
authors.forename: K K
authors.initials: KK
authors.lastname: Qumei
authors.forename: P M
authors.initials: PM
authors.lastname: Roblin
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin; D002478:Cells, Cultured; D016993:Chlamydophila pneumoniae / Q000187:drug effects*; D017291:Clarithromycin; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D015242:Ofloxacin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D004917:Erythromycin; D017963:Azithromycin; D015242:Ofloxacin; D017291:Clarithromycin