Breakpoints ??
Classical breakpoints of older FQs and of levofloxacin are probably set too high and correspond to AUC / MIC -based PK/PD breakpoints only if
- clearance is lower than in normal subjects
- accepting an AUC / MIC ratio of 25 as being sufficient…
- considering total concentrations
Classical FQ breakpoints almost never correspond to a peak / MIC ratio ? 10 !