Safety and Efficacy of Prophylactic Levofloxacin in Pediatric and Adult Hematopoietic Stem Cell Transplantation Patients.

Levofloxacin has been widely used for bacteremia prophylaxis in the pre-engraftment setting for patients undergoing hematopoietic stem cell transplantation (HSCT), but data supporting this practice are inconsistent. In addition to concern for lack of benefit, there are also concerns that this practice could increase the rates of Clostridioides difficile (C diff) infections, the incidence of multidrug-resistant organisms (MDRO) or lead to increased incidence of acute graft-versus-host disease (aGVHD) by disrupting the gut microbiome. This study aimed to assess the safety and efficacy of levofloxacin as bacterial prophylaxis in pediatric and young adult patients undergoing allogeneic or autologous HSCT at a single pediatric center. We conducted a retrospective chart review evaluating patients age ≥6 months who underwent HSCT at our center between January 1, 2016, and July 31, 2020. Patients who underwent transplantation before March 2018 did not receive levofloxacin prophylaxis, whereas those who underwent transplantation after April 2018 did receive levofloxacin prophylaxis. Each transplantation was included as a separate episode if the patient underwent more than 1 transplantation during the inclusion time. The primary outcome of this study was the proportion of patients who experienced at least 1 bacterial bloodstream infection (BSI) in the first 100 days post-transplantation. Secondary outcomes included the number of non-levofloxacin antibiotic days post-transplantation, the incidence of aGVHD, the occurrence of C diff infections, and development of MDRO. A total of 370 HSCT recipients with a median age of 6.7 years (range, 0.5 to 39 years) were included in this study. Seventy-two patients had undergone more than 1 transplantation, and thus we had 443 transplantations to observe. Of these, 216 did not include levofloxacin prophylaxis and 227 included levofloxacin prophylaxis. There were no differences in baseline characteristics between the 2 groups except for age; patients in the non-levofloxacin prophylaxis group were younger (8.1 years vs 9.6 years; P = .05). There were no between-group differences in rates of death at 100 days, antibiotic use, fungal infections, or MDRO infections. Patients in the non-prophylaxis group developed more bacterial BSI in the first 100 days post-HSCT (27% versus 17%; P = .004) and more C diff infections (20% versus 9%; P = .003) than patients who received levofloxacin prophylaxis. In addition, more aGVHD was seen in the patients without levofloxacin prophylaxis (P = .014). Levofloxacin prophylaxis given from day -2 of HSCT through engraftment was significantly associated with decreased bacterial BSI in the first 100 days post-transplantation and was not associated with increased risks of C diff, aGVHD, or MDRO. Our study supports the use of levofloxacin prophylaxis in the peritransplantation period. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.