Noncarbapenems for the Treatment of Urinary Tract Infections Caused by Extended-Spectrum β-Lactamase-Producing Bacteria.

OBJECTIVES: Urinary tract infections (UTIs) caused by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are resistant to many conventional therapies, including third-generation cephalosporins. Carbapenems are considered first-line agents for ESBL infections, but their use is associated with increased multidrug resistance and should be reserved when absolutely necessary. Because of the increased rates of UTIs caused by ESBL-producing organisms and incidence of carbapenem resistance, safe and effective alternatives to carbapenems are needed. This study was conducted to evaluate the outcomes associated with the treatment of ESBL UTIs with noncarbapenem antibiotics.

METHODS: A retrospective cohort study of adults with ESBL UTIs was conducted at a community hospital. Patients were categorized as those receiving definitive carbapenem therapy and those receiving definitive noncarbapenem therapy. Calculated measurements included infection-related mortality, length of hospital stay, and duration of definitive antibiotic therapy. Microbiological failure was assessed as a secondary outcome. Data on the safety of antibiotic therapy were not collected. P < 0.05 was considered significant.

RESULTS: Fifty patients met inclusion criteria for the study, divided evenly between the two cohorts. No statistical differences were observed for length of hospital stay (P = 0.601), duration of therapy (P = 0.398), or rate of microbiological failure between the groups (P = 0.115).

CONCLUSIONS: Noncarbapenems did not demonstrate significant differences compared with carbapenems in the treatment of adults with ESBL UTIs. In certain patient populations, noncarbapenems that demonstrate in vitro activity may be appropriate for UTIs caused by ESBL-producing organisms.