Antibiotic use during cytarabine consolidation in acute myeloid leukemia

Acute myeloid leukemia (AML) patients undergoing consolidation chemotherapy with intermediate or high-dose cytarabine (IDAC/HiDAC) are often placed on prophylactic antibacterials. This practice is largely based on the benefits of prophylaxis (PPX) during induction chemotherapy. However, recent concerns regarding antibacterial prophylaxis have emerged including risk of Clostridioides difficile colitis, medication toxicities, and the potential for fostering multidrug-resistant pathogens. We therefore retrospectively explored whether antibacterial PPX is beneficial during cytarabine consolidation. Adult AML patients who received IDAC/HiDAC at our institution from January 2007 to March 2018 were evaluated for receipt of antibacterial PPX. The primary endpoint was rate of febrile neutropenia (FN); secondary endpoints were rates of unplanned hospitalization, bacteremia, infection from resistant organisms, C. difficile colitis, and death from infection. One hundred twenty patients with data from 229 IDAC/HiDAC cycles were included. Patients who received antibacterial PPX were more often hospitalized during cytarabine cycle 1 (C1) than those who received no PPX. Patients who received PPX had significantly more episodes of bacteremia, in addition to infections from resistant, predominantly Gram-positive organisms during cycle 1 of consolidation than those without PPX. Antibacterial PPX during IDAC/HiDAC consolidation treatment at our institution did not decrease the rates of FN, hospitalization, or bacteremia and was associated with higher risk of infection from drug-resistant bacteria in C1. Prospective studies examining antibacterial prophylaxis during cytarabine consolidation for AML patients are necessary, with strong consideration made for institution-specific protocols.