title: Reducing empirical use of fluoroquinolones for Pseudomonas aeruginosa infections improves outcome.
abstract: BACKGROUND
  We previously reported ciprofloxacin resistance (CR) and empirical use of fluoroquinolones as predictors of mortality in patients infected with Pseudomonas aeruginosa in a case-control study. Here, we assessed the clinical impact of reducing empirical fluoroquinolone use for P. aeruginosa infections in hospitalized patients by performing a follow-up study in 2005-06 [period 2 (P2)] and comparing this with prior data from 2001-02 [period 1 (P1)].
  
  
  METHODS
  Medical charts of infected patients who received at least 72 h of antibiotic therapy were reviewed. Patients were subgrouped based on the susceptibility of infected strains into the CR or ciprofloxacin-susceptible group. Antibiograms, patient and treatment variables and outcome measures were compared between groups and between study periods.
  
  
  RESULTS
  Study patients were elderly (median age, 76 years), had a median of three co-morbidities and a median APACHE II score of 13. Most (75%) had pneumonia or urosepsis. Empirical use of fluoroquinolones was reduced by 30% in P2 versus P1, with a corresponding 39% increase in piperacillin/tazobactam use. The resultant positive impact observed in the CR group during P2 includes shortened delay to receipt of effective therapy (1 versus 3.5 days, P < 0.0001), reduced length of stay (13 versus 16 days, P = 0.03) and 2-fold lower mortality (9% versus 22%, P = 0.05). Susceptibility of P. aeruginosa improved by 10% to all antipseudomonal agents tested.
  
  
  CONCLUSIONS
  In settings where high rates of fluoroquinolone resistance exist, use of non-fluoroquinolone-based empirical regimens for P. aeruginosa infections improves patient outcomes and organism susceptibility over time.
authors.affiliation: Loma Linda University, School of Pharmacy, Loma Linda, CA, USA.
authors.forename: Lee H
authors.initials: LH
authors.lastname: Nguyen
authors.forename: Donald I
authors.initials: DI
authors.lastname: Hsu
authors.forename: Vaidyanathan
authors.initials: V
authors.lastname: Ganapathy
authors.forename: Kimberly
authors.initials: K
authors.lastname: Shriner
authors.forename: Annie
authors.initials: A
authors.lastname: Wong-Beringer
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D036262:Empirical Research; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000302:isolation & purification; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D024841:Fluoroquinolones