[Evaluation of efficacy of oral quinolone against Streptococcus pneumoniae AND Haemophilus influenzae with the use of Monte Carlo simulation].

We investigated the efficacies of various administration methods for levofloxacin (LVFX) and tosufloxacin (TFLX) against 161 isolates of Streptococcus pneumoniae and 309 isolates of Haemophilus influenzae isolated in Gifu prefecture, using Monte Carlo simulation. The pharmacokinetic parameters of the fluoroquinolones were calculated from changes in blood concentration in healthy adults. Monte Carlo simulation was performed for 1,000 times to determine the AUC/MIC target attainment rates for various administration methods for fluoroquinolones (LVFX: 100 mgx3, 200 mgx2, 500 mgx 1, TFLX: 150 mgx3, 300 mgx2) with Crystal Ball 7. For S. pneumoniae, target attainment rates ofAUC/MIC; 30 were 47.18%, 75.54%, 89.16%, 93.63% and 98.63% for LVFX 100mgx3, LVFX 200mgx2, LVFX 500mgxl, TFLX 150mgx3 and TFLX 300mgx2, respectively. For H. influenzae, target attainment rates of AUC/MIC; 125 were 99.20%, 99.05%, 99.54%, 99.66% and 100% for LVFX 100mgx3, LVFX 200mgx2, LVFX 500mgxl, TFLX 150mgx3 and TFLX 300mgx2, respectively. These results suggest that administration methods might have a large impact on the efficacy of treatment with oral fluoroquinolones, and to determine administration method based on PK/PD would be important in clinical practices.