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. © The Author 2008. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved.