Characterization of the onset and consequences of pneumonia due to fluoroquinolone-susceptible or -resistant Pseudomonas aeruginosa

J Antimicrob Chemother. 2003 Sep;52(3):457-63. doi: 10.1093/jac/dkg342. Epub 2003 Jul 29.

Abstract

Objectives: This study was conducted to identify and compare the microbiological and clinical outcomes among hospitalized adults with pneumonia caused by fluoroquinolone-susceptible or -resistant strains of Pseudomonas aeruginosa. Antibiotic regimens used prior to, as well as those used to treat, the infections were characterized.

Patients and methods: This non-randomized multicentre study included 100 consecutively identified patients with pneumonia caused by fluoroquinolone-susceptible (n = 50) or fluoroquinolone-resistant (n = 50) strains of P. aeruginosa. Medical records were examined for demographic, clinical and treatment variables including antibiotics received in the 30 days before the index respiratory or blood culture; AUICs were calculated for each patient using reported or derived MICs. Multivariate logistic and linear regressions were used to identify factors associated with successful clinical and microbiological outcomes.

Results: The study population was primarily elderly, frequently in a critical care unit, with low serum albumin and with a high probability of failure and mortality. Patients with pneumonia caused by fluoroquinolone-resistant P. aeruginosa were more likely to have received antibiotics within 7 days before the infection (P = 0.027); the antibiotic regimen was more likely to be of a weak potency (mean AUIC of 58 versus 169, P = 0.001) and to include levofloxacin (P < 0.0001) than what was administered to patients who became infected with a fluoroquinolone-susceptible strain. Regardless of susceptibility, a mean of between 2 and 3 weeks of directed antibiotic therapy was administered to each patient.

Conclusions: Pneumonia caused by fluoroquinolone-resistant P. aeruginosa is frequently associated with prior exposure to levofloxacin. Treatment of P. aeruginosa pneumonia is difficult and usually consists of combination regimens with multiple modifications.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Anti-Bacterial Agents / economics
  • Anti-Bacterial Agents / pharmacology*
  • Anti-Bacterial Agents / therapeutic use
  • Area Under Curve
  • Drug Resistance, Bacterial
  • Female
  • Fluoroquinolones / economics
  • Fluoroquinolones / pharmacology*
  • Fluoroquinolones / therapeutic use
  • Humans
  • Levofloxacin
  • Logistic Models
  • Male
  • Middle Aged
  • Ofloxacin / adverse effects
  • Ofloxacin / therapeutic use
  • Pneumonia, Bacterial / drug therapy
  • Pneumonia, Bacterial / economics
  • Pneumonia, Bacterial / microbiology*
  • Pseudomonas Infections / drug therapy
  • Pseudomonas Infections / economics
  • Pseudomonas Infections / microbiology*
  • Pseudomonas aeruginosa / drug effects*
  • Treatment Outcome

Substances

  • Anti-Bacterial Agents
  • Fluoroquinolones
  • Levofloxacin
  • Ofloxacin