Potent antibacterial activities of latamoxef (moxalactam) against ESBL producing Enterobacteriaceae analyzed by Monte Carlo simulation

Latamoxef (LMOX, Moxalactam) is one of the beta-lactam antibiotics which is stable against beta-lactamase. In this study, the antibacterial activity of LMOX was investigated, and Monte Carlo simulation was conducted to determine the appropriate dosing regimens of LMOX against extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae. The probability of target attainment (PTA) was analyzed at 40% and 70% of time above minimum inhibitory concentration (MIC) (time above MIC, T(>MIC)) for bacteriostatic and bactericidal effect respectively. All the tested regimens achieved 85% of PTA at 40% of T(>MIC) against ESBL producing Escherichia coli, and all the tested regimens except 1g q12h with 1 hour infusion achieved 85% of PTA at 40% of T(>MIC) against ESBL producing Klebsiella pneumoniae. The effective regimens to achieve 85% of PTA at 70% of T(>MIC )against E. coli were lg ql2h with 4 hours infusion, lg q8h with 1-4 hours infusion, 2g ql2h with 2-4 hours infusion, and lg q6h with 1-4 hours infusion. The effective regimens to achieve 85% of PTA at 70% of T(>MIC) against K. pneumoniae were 1g q8h with 3-4 hours infusion and 1g q6h with 1-4 hours infusion. These results of pharmacokinetics/pharmacodynamics (PK/PD) modeling showed the potent efficacy of LMOX against bacterial infections caused by ESBL producing Enterobacteriaceae.