Pharmacological study of cefoxitin as an alternative antibiotic therapy to carbapenems in treatment of urinary tract infections due to extended-spectrum-β-lactamase-producing Escherichia coli.

Cefoxitin could be an alternative to carbapenems in extended-spectrum-beta-lactamase-producing Escherichia coli (ESBL-EC) infections. However, pharmacological and clinical data regarding cefoxitin are limited. Using a recent pharmacological model and the MICs of ESBL-EC collected from pyelonephritis, we determined the probabilities to reach four pharmacological targets: free cefoxitin concentrations above the MIC during 50% and 100% of the administration interval (T>MIC = 50% and T>MIC = 100%, respectively) and free cefoxitin concentrations above 4× MIC during 50% and 100% of the administration interval (T>4MIC = 50% and T>4MIC = 100%, respectively). Cefoxitin could be used to treat ESBL-EC pyelonephritis, but administration modalities should be optimized according to MICs in order to reach pharmacological targets.