Clostridioides difficile Infection in Hematology-Oncology Patients Receiving Bacterial Prophylaxis With Levofloxacin: A Single-Institution Experience.

Background and objectives Prophylactic levofloxacin reduces the risk of bacteremia in patients with treatment-induced neutropenia. However, fluoroquinolone use has been linked to an increased risk of Clostridioides difficile infections (CDI), which can be associated with delays in treatment schedules or prolonged hospital stays in hematology/oncology patients. Due to a lack of convincing evidence, routine CDI prophylactic interventions are not currently recommended. In this context, we aimed to assess how prophylactic levofloxacin in pediatric hematology-oncology patients affects CDI rates at our institution and whether there is a rationale for implementing CDI prophylactic measures in this population.  Methods We conducted a retrospective chart review of prophylactic levofloxacin administration records in patients admitted to our pediatric hematology-oncology unit between January 2022 and June 2023. Only records documenting more than four days of continuous exposure to levofloxacin were included. Patients were excluded if levofloxacin was administered exclusively in the outpatient setting, if they did not have a primary hematologic or oncologic diagnosis, or if levofloxacin was administered for purposes other than antibacterial prophylaxis. Cases of CDI were identified as the presence of diarrhea with a positive stool C. difficile toxin A/B enzyme immunoassay or nucleic acid amplification test. CDIs that occurred within 30 days of documented levofloxacin exposure were then reported. Results We found 408 records of levofloxacin exposure in 234 patients between January 2022 and June 2023. Seventy-five patients included in the final analysis received a total of 1851 days of levofloxacin prophylaxis in 129 recorded exposures (mean: 14.35 days per exposure, range: 4-76 days). CDI occurred in 10 patients (13.3%) at some point after a hematologic or oncologic diagnosis had been established. We identified five cases of CDI within 30 days of the last day of levofloxacin prophylaxis; thus, CDI occurred in 6.67% of all patients and 3.88% of all exposures. Three of these cases occurred after cessation of levofloxacin and the administration of intravenous broad-spectrum antibiotics for febrile neutropenia. Only two of the patients who developed CDI within that time frame had not received any antibiotics other than levofloxacin immediately before the infection. One of these patients had complete resolution of the infection with an oral antibiotic course, while the other died within six days due to unrelated infectious causes. Conclusions Levofloxacin antimicrobial prophylaxis in neutropenic patients does not appear to be associated with an increased risk of CDI or with an increased risk of adverse outcomes from the infection. This study does not provide evidence supporting the need for additional CDI prophylactic measures, such as antibiotics, in these patients.