This followed a 2012 French study on the same E. coli strain with CTX-M-15 extended release beta-lactamase. Lepeule et al. determined that in mice, the ideal pharmacodynamic target of fT>MIC=33%, where MIC is the minimum inhibitory concentration, was obtained with 200 mg/kg every four hours. The fT>MIC (%) was increased by 11% when the administration frequency was increased from every four hours to every three hours. This implied that increasing the frequency might yield similar results in humans. The study also found no significant difference between the effectiveness of carbapenems and cefoxitin and suggested that cefoxitin can be used as an alternative treatment for CTX-M producing E. coli to carbapenems such as imipenem and ertapenem.