title: Clinical outcomes with ertapenem as a first-line treatment option of infections caused by extended-spectrum β-lactamase producing gram-negative bacteria.
abstract: BACKGROUND
  Infections caused by extended-spectrum β-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.
authors.affiliation: Massachusetts College of Pharmacy and Health Sciences-Worcester, Worcester, MA, USA. jeffrey.fong@mcphs.edu
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Fong
authors.forename: Lucia
authors.initials: L
authors.lastname: Rosé
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Radigan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000077727:Ertapenem; D004927:Escherichia coli Infections / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D001618:beta-Lactamases / Q000378:metabolism; D047090:beta-Lactams / Q000627:therapeutic use*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D001618:beta-Lactamases; D000077727:Ertapenem