Oral fluoroquinolones for definitive treatment of gram-negative bacteremia in cancer patients

Abstract

Purpose: Bloodstream infections (BSI) are significant causes of morbidity and mortality in cancer patients. These patients often receive 10 to 14 days of intravenous (IV) antibiotics. The objective of this study was to compare the outcomes of cancer patients transitioned from IV to oral (PO) therapy compared to continuation of IV treatment.

Methods: This was a single-center, retrospective cohort study of hospitalized adult cancer patients with gram-negative bacteremia. Patients transitioned to a PO fluoroquinolone (FQ) within 5 days were allocated to the IV-to-PO group, while the remaining patients comprised the IV group. The primary outcome was the composite of treatment failure, defined as infection-related readmission, infection recurrence, or inpatient mortality. A multivariable logistic regression model was constructed to account for confounding variables. Secondary outcomes assessed included infection-related length of stay (LOS), hospital LOS, and adverse events, such as Clostridioides difficile infection and catheter-related complications.

Results: The IV-to-PO group included 78 patients, while the remaining 133 patients were allocated to the IV group. Differences at baseline included more hematologic malignancy, neutropenia, ICU admissions, and higher Pitt bacteremia scores in the IV group. The rate of treatment failure was significantly higher in the IV group (24% vs 9%; p < 0.01), which persisted in the logistic regression (aOR 3.5, 95% CI 1.3-9.1). The IV-to-PO group had decreased infection-related and hospital length of stay, as well as fewer catheter-related complications.

Conclusions: The use of PO FQ may be considered for the definitive treatment of uncomplicated Enterobacterales BSI in cancer patients.

Keywords: Bacteremia; Cancer; Fluoroquinolones; Gram-negative bacterial infections.