Killing kinetics of five orally administered antibiotics at clinically achievable concentrations against Moraxella catarrhalis.
Time-kill kinetic studies were used to measure the bactericidal activity of amoxicillin/clavulanic acid (in a new form for pediatric use), cefaclor, cefuroxime, cefixime and erythromycin against 30 beta-lactamase producing Moraxella catarrhalis strains. Antibiotics were tested at the mean maximum serum concentration observed after administration of a standard dose and at 0.5 x Cmax, 0.33 x Cmax and 0.25 x Cmax. A 2 log10 reduction in colony counts was obtained with the Cmax of amoxicillin/clavulanic acid and cefixime after 5 h of incubation. After 24 h of incubation a decrease of 3 and 4 log was observed with cefixime and amoxicillin/clavulanic acid respectively. At 0.5 x Cmax and 0.33 x Cmax, bactericidal activity was obtained only with amoxicillin/clavulanic acid.
Bingen
E
E
Service de Microbiologie, Hôpital Robert Debré, Paris, France.
Bourgeois
F
F
Chardon
H
H
Doit
C
C
Lambert-Zechovsky
N
N
D000658:Amoxicillin / Q000494:pharmacology; D019980:Amoxicillin-Potassium Clavulanate Combination; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002433:Cefaclor / Q000494:pharmacology; D020682:Cefixime; D002439:Cefotaxime / Q000031:analogs & derivatives / Q000494:pharmacology; D002444:Cefuroxime / Q000494:pharmacology; D002648:Child; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D015169:Colony Count, Microbial; D004338:Drug Combinations; D004359:Drug Therapy, Combination / Q000494:pharmacology; D004917:Erythromycin / Q000494:pharmacology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D001936:Moraxella catarrhalis / Q000187:drug effects* / Q000201:enzymology
D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; D004338:Drug Combinations; D019818:Clavulanic Acid; D004917:Erythromycin; D002433:Cefaclor; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin; D020682:Cefixime; D002439:Cefotaxime; D002444:Cefuroxime