title: Activity of clarithromycin and its principal human metabolite against Haemophilus influenzae.
abstract: Clarithromycin is a new macrolide antibiotic which forms a microbiologically active principal in vivo metabolite, 14-OH-clarithromycin. The in vitro activities of clarithromycin and its metabolite were examined separately and in pharmacokinetically relevant fixed combinations of 4:1 and 2:1 against a group of 50 Haemophilus influenzae isolates. Broth microdilution susceptibility tests indicated that clarithromycin was less active than erythromycin against all but highly erythromycin-susceptible strains, while 14-OH-clarithromycin was generally more active than either antibiotic. An enhancement in activity against the majority of strains was demonstrated when clarithromycin and its metabolite were tested in combination.
authors.affiliation: Department of Pathology, University of Texas Health Science Center, San Antonio 78284-7750.
authors.forename: J H
authors.initials: JH
authors.lastname: Jorgensen
authors.forename: L A
authors.initials: LA
authors.lastname: Maher
authors.forename: A W
authors.initials: AW
authors.lastname: Howell
mesh_terms: D017291:Clarithromycin / Q000031:analogs & derivatives; D004352:Drug Resistance, Microbial; D004917:Erythromycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D006193:Haemophilus influenzae / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests
chemical_list: C056228:14-hydroxyclarithromycin; D004917:Erythromycin; D017291:Clarithromycin