Ofloxacin: bactericidal effect in an in vitro pharmacokinetic model

Ofloxacin has been evaluated in an in vitro model where microorganisms were exposed to the varying concentrations met in human serum after the oral administration of a 200 mg dose. The recently isolated strains were selected with minimum inhibitory concentrations (MICs) representative of the MICs 90% of ofloxacin against the species considered. Results showed that ofloxacin sterilized the bacterial cultures of S. aureus, P. morganii and E. coli, with 99.99% of killing still evident for P. aeruginosa after 12 hours of exposure. All the reference compounds (amoxicillin 1 g b.i.d., cefaclor 500 mg t.i.d., rifampicin 450 mg b.i.d.) showed, in the same test, worse results than ofloxacin.