Impact of a change in antibacterial prophylaxis on bacteremia and hospitalization rates following outpatient autologous peripheral blood stem cell transplantation for multiple myeloma.

BACKGROUND: Levofloxacin is routinely used for the prevention of invasive bacterial infections during autologous peripheral blood stem cell transplantation (APBSCT). However, increasing rates of bacterial sepsis were noted at our institution among multiple myeloma (MM) patients undergoing outpatient APBSCT with melphalan-based chemotherapy and levofloxacin prophylaxis. We assessed the impact of a change in antibacterial prophylaxis from oral levofloxacin (Period 1) to sequential oral levofloxacin followed by ertapenem (Period 2).
METHODS: Electronic medical records were reviewed to identify MM patients who underwent APBSCT in the outpatient clinic between October 2007 and April 2012.
RESULTS: Over a 4.5-year period, 165 outpatient APBSCTs were eligible for the analysis. Fewer overall bacteremias occurred during Period 2 as compared with Period 1 (0.5 cases per 100 person-days vs. 2.4 cases per 100 person-days, P<0.001). In addition, fewer patients were hospitalized for neutropenic fever while receiving sequential prophylaxis (45.7% vs. 75.7% of outpatient APBSCT recipients during Periods 2 and 1, respectively; P<0.001). In Kaplan-Meier analysis, receipt of sequential prophylaxis (Period 2) was significantly associated with overall bacteremia-free survival within 30 days after the APBSCT (P<0.001). No significant differences were seen in the number of patients developing Clostridium difficile infection or ertapenem-resistant gram-negative bacteremia between study periods.
CONCLUSION: In conclusion, sequential prophylaxis may effectively prevent episodes of bacteremia and hospitalizations in neutropenic MM outpatient APBSCT recipients. Prospective studies that involve larger numbers of MM patients with extended periods of follow-up are ultimately required to define the safety and efficacy of sequential antibacterial prophylaxis.