Clinical Outcomes with Ertapenem as a First-Line Treatment Option of Infections Caused by Extended-Spectrum β-Lactamase Producing Gram-Negative Bacteria

BACKGROUND: Infections caused by extended-spectrum beta-lactamase (ESBL) producing gram-negative organisms are a growing concern in hospitalized patients. Traditionally, these infections can be effectively treated by the carbapenem class of drugs. In 2005, our institution initiated a protocol for use of ertapenem, a carbapenem, as the first-line treatment option for these infections. It is unknown whether ertapenem is associated with similar clinical response and microbiologic cure rates as those achieved with group 2 carbapenems (imipenem, meropenem, doripenem). OBJECTIVE: To describe clinical response and microbiologic cure rates associated with ertapenem as first-line treatment of infections caused by ESBL-producing organisms. METHODS: This case series included patients who received ertapenem for more than 48 hours to treat a documented infection with a positive culture for an ESBL-producing organism. Efficacy was determined by the clinical response and microbiologic cure rates achieved with ertapenem. RESULTS: Seventy-three patients received ertapenem for a mean (SD) of 10.7 (5.9) days. The most common (59%) infection site was urine. The most common causative organisms were ESBL-producing Klebsiella pneumoniae (47%) and Escherichia coli (48%). Clinical response was observed in 78% of patients. Microbiologic cure was achieved in 92% of the evaluable population (n = 50). There were no significant differences in clinical or microbiologic cure rates across important subgroups. CONCLUSIONS: Patients treated with ertapenem achieved favorable clinical response and microbiologic cure rates. Our data suggest that ertapenem can be used as an alternative to group 2 carbapenems for the treatment of infections caused by ESBL-producing gram-negative organisms.