Short-term bactericidal activity of amoxicillin and cefotaxime against penicillin-susceptible and -resistant pneumococcal strains: an in vitro pharmacodynamic simulation.
The 8-hour in vitro activity of serum-simulated concentrations of amoxicillin (obtained after 875 mg oral dose) and cefotaxime (obtained after a 1 g i.v. dose), against 20 strains of the 5 Streptococcus pneumoniae serotypes most prevalent in Spain, was explored. Despite a greater initial inocula decrease observed with cefotaxime against the resistant strains at the first sampling time, a decrease > or =99.9% was obtained with both beta-lactams from 6h onwards against the penicillin-susceptible strains; the same was observed for the penicillin-resistant strains with amoxicillin but not with cefotaxime.
Fenoll
A
A
Pneumococcal Reference Laboratory, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
Casal
J
J
Giménez
M J
MJ
Jado
I
I
Aguilar
L
L
D000284:Administration, Oral; D000658:Amoxicillin / Q000008:administration & dosage / Q000494:pharmacology*; D002439:Cefotaxime / Q000008:administration & dosage / Q000494:pharmacology*; D002511:Cephalosporins / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007262:Infusions, Intravenous; D008826:Microbial Sensitivity Tests / Q000379:methods; D010403:Penicillin Resistance; D010406:Penicillins / Q000008:administration & dosage / Q000494:pharmacology*; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology; D013030:Spain / Q000453:epidemiology; D013296:Streptococcus pneumoniae / Q000145:classification / Q000187:drug effects*
D002511:Cephalosporins; D010406:Penicillins; D000658:Amoxicillin; D002439:Cefotaxime