title: Clinical and bacteriological efficacy of the ketolide telithromycin against isolates of key respiratory pathogens: a pooled analysis of phase III studies.
abstract: A pooled analysis of data from 13 phase III studies of telithromycin in the treatment of community-acquired pneumonia, acute exacerbations of chronic bronchitis, acute sinusitis or group A beta-haemolytic streptococcal pharyngitis and tonsillitis was undertaken. Causative key respiratory tract pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus and Streptococcus pyogenes) were isolated at entry to the studies from cultures of relevant respiratory samples and tested for their susceptibility to telithromycin, penicillin and macrolides (erythromycin A). The combined clinical and bacteriological efficacy of telithromycin at the post-therapy, test-of-cure visit (days 17-24) was assessed in patients from whom a microbiologically evaluable pathogen was isolated at entry. More than 98% of key respiratory pathogens isolated, including penicillin G- and macrolide (erythromycin A)-resistant strains of S. pneumoniae, demonstrated full or intermediate susceptibility to telithromycin in vitro at the breakpoints of < or = 1.0 mg/L (susceptible) and 2.0 mg/L (intermediate) used for the purpose of evaluating the susceptibility of isolates recovered during the clinical trials. Treatment with telithromycin 800 mg once-daily for 5, 7 or 7-10 days resulted in high rates of clinical cure (88.5%) and a satisfactory bacteriological outcome (88.9%), similar to the figures seen with comparator antibacterial agents. Clinical cure and eradication rates were good for all key respiratory pathogens, including penicillin G- and macrolide (erythromycin A)-resistant S. pneumoniae. The results suggest that telithromycin will provide effective empirical therapy for community-acquired upper and lower respiratory tract infections.
authors.affiliation: Mount Sinai Hospital, Department of Microbiology, University of Toronto, 600 University Avenue, Room 1487, Toronto, Ontario, Canada M5G 1X5. dlow@mtsinai.on.ca
authors.forename: D E
authors.initials: DE
authors.lastname: Low
authors.forename: S
authors.initials: S
authors.lastname: Brown
authors.forename: D
authors.initials: D
authors.lastname: Felmingham
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001419:Bacteria / Q000145:classification / Q000187:drug effects* / Q000302:isolation & purification; D017326:Clinical Trials, Phase III as Topic; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000382:microbiology; D006193:Haemophilus influenzae / Q000187:drug effects / Q000302:isolation & purification; D006801:Humans; D048628:Ketolides; D018942:Macrolides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D001936:Moraxella catarrhalis / Q000187:drug effects / Q000302:isolation & purification; D016032:Randomized Controlled Trials as Topic; D012141:Respiratory Tract Infections / Q000188:drug therapy* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000302:isolation & purification; D016896:Treatment Outcome
chemical_list: D048628:Ketolides; D018942:Macrolides; C106791:telithromycin