Fig. 5
Monte Carlo simulation was performed to evaluate the PTA attainment of Tfree > MIC for over 80% and for 100% of the dosing interval. The PTA for the 80% dosing interval was 0% for MIC = 1 mg/L with the 1 g dose, and 99% with the 2 g dose in the sham rats. In the CLP rats, the PTA for the 80% dosing interval was 75% for MIC = 1 for the 1 g dose and 95% for the 2 g dose (a, b). Probability of target attainment (PTA) was calculated for the two dosing regimens 100 (blue line) and 200 (red line) mg/kg (corresponding to 1 and 2 g in humans respectively), using Monte Carlo simulation based on the PK model. The time period during which free concentrations remained higher then MIC (Tfree > MIC) and the PTA for different multiples of MIC were estimated graphically. MIC values according to the EUCAST breakpoints were considered, with CTX susceptibility for Enterobacteriaceae being ≤1 mg/L [34]. The PTA for the 100% dosing interval was 0% for MIC = 1 mg/L for both the 1 g and 2 g doses in both the sham rats (c) and the CLP rats (d)