A single-center evaluation of the risk for colonization or bacteremia with piperacillin-tazobactam- and cefepime-resistant bacteria in patients with acute leukemia receiving fluoroquinolone prophylaxis.

ABSTRACT

Fluoroquinolone prophylaxis is indicated to prevent neutropenic fever in patients with acute leukemia. However, fluoroquinolone use has been associated with development of multi-drug-resistant Pseudomonas aeruginosa and extended spectrum ß-lactamase producing gram-negative bacilli. Due to a presumed risk of multi-drug resistance associated with fluoroquinolone prophylaxis, patients admitted to our hospital with neutropenic fever receive empiric carbapenem therapy until cultures are negative for 72 h or identification of an organism. Our study seeks to identify the incidence of multi-drug-resistant organism colonization and bacteremia among patients who receive fluoroquinolone prophylaxis and to evaluate duration of empiric carbapenem therapy. A retrospective review of adult patients with acute leukemia receiving a fluoroquinolone as outpatient infection prophylaxis, admitted to our tertiary cancer center for treatment of neutropenic fever was completed. Surveillance and blood cultures were reviewed for antibiotic resistance. Duration of empiric carbapenem therapy was reviewed. One hundred patients and 177 admissions for neutropenic fever were included. Six patients harbored a piperacillin-tazobactam-resistant organism found during routine surveillance. Among these patients, two bacteremias were identified, one of which was a piperacillin-tazobactam-resistant organism. Five bacteremias were identified among 83 patients with negative surveillance cultures. Among the bloodstream infections, five organisms isolated were fluoroquinolone resistant. No cefepime-resistant organism was isolated on surveillance or bloodstream cultures. Adherence to the institution guideline of narrowing antibiotics after 72 h of negative cultures occurred in only 13% of neutropenic fever cases. The average duration of carbapenem therapy in 177 neutropenic fever episodes was 4.4 days. Our findings show that among our patient population, there is a low risk of bacteremia with a piperacillin-tazobactam-resistant or cefepime-resistant organism. However, prompt de-escalation of carbapenem therapy needs to be reiterated within hospital practice.