Impact of antibacterial prophylaxis during reinduction chemotherapy for relapse/refractory acute myeloid leukemia

This study evaluated the impact of antibacterial prophylaxis with levofloxacin in relapsed/refractory acute myeloid leukemia (AML) patients. This was a retrospective, single-center, cohort study. Adult patients with relapsed/refractory AML admitted for reinduction chemotherapy between November 1, 2006 and June 15, 2015 were screened for inclusion. A protocol initiating levofloxacin prophylaxis was implemented on December 1, 2013. Patients receiving hypomethylating agents (decitabine/azacitidine) were not administered antibacterial prophylaxis and thus not included in this analysis. Patients receiving broad spectrum antibiotics on day 1 of reinduction chemotherapy or receiving another antibacterial agent for prophylaxis were also excluded. Ninety-seven patients were included in the control group (no prophylaxis), while 48 patients received levofloxacin prophylaxis. Patients in the prophylaxis group received levofloxacin 500 mg once daily on day 1 of chemotherapy and continued until neutrophil recovery (or hospital discharge or death). There was a reduction in the rate of bacteremia in the prophylaxis group (37.5 %) compared to the control group (53.6 %, p = 0.0789), largely due to a reduction in gram-negative bacteremia (2.1 vs. 21.6 % respectively, p = 0.001). No difference was found between prophylaxis and the control groups in the incidence of neutropenic fever, incidence of multidrug resistance, length of hospital or ICU stay, or mortality. Levofloxacin prophylaxis reduced the rate of infections overall in adult patients with relapsed/refractory AML, without increasing rates of multidrug-resistant organisms.