Fluoroquinolone Prophylaxis Reduces Intensive Care Unit Admission and Clostridioides difficile Rates in Acute Myeloid...

Patients with acute myeloid leukemia (AML) undergoing induction chemotherapy are at high-risk of bloodstream infections, including central line-associated bloodstream infections (CLABSI) or mucosal barrier injury-related infections (MBI-LCBI). The impact of fluoroquinolone (FQ) prophylaxis on MBI-LCBI, Clostridioides difficile, and intensive care unit (ICU) outcomes in this population remains unclear.

We retrospectively reviewed adults with AML receiving induction chemotherapy between 2010 and 2022. Patients were grouped by receipt of FQ prophylaxis. Primary outcomes were incidence of CLABSI, and MBI-LCBI. Secondary outcomes included neutropenic fever, ICU admission, length of stay, and C. difficile infection. Microbiologic patterns were analyzed by time and prophylaxis status.

Among 195 patients, 88 (45.1%) received FQ prophylaxis. CLABSI rates were 8.0% with prophylaxis versus 15.0% without (p = 0.132), and MBI-LCBI rates were 11.4% versus 15.0% (p = 0.463). ICU admission was significantly lower with prophylaxis (10.2% vs. 31.8%; p < 0.001). C. difficile infection was also less frequent among those receiving prophylaxis (5.7% vs. 17.8%; p = 0.012). Neutropenic fever rates were similar between groups. CLABSI isolates were primarily skin flora and staphylococcal species, whereas MBI-LCBI isolates were exclusively enteric flora, increasingly involving Gram-negative rods over time. Pseudomonas infections were more frequent among patients without prophylaxis.

In this cohort, FQ prophylaxis did not significantly reduce bloodstream infections but was associated with fewer ICU admissions and lower rates of C. difficile infection. These findings further support the use of FQ prophylaxis with minimal concern for exacerbation of C. difficile rates. It further highlights ongoing risk from enteric translocation despite prophylaxis.