Fluoroquinolone Prophylaxis in Acute Myeloid Leukemia (AML) Patients Undergoing Post-Remission Chemotherapy Reduces Hospital Admission Rates

High-dose cytarabine (HIDAC) is a standard treatment for younger AML patients (pts) receiving post-remission chemotherapy. The risk for febrile neutropenia (FN) is high among these pts and considered a medical emergency, requiring prompt hospital admission and treatment. In 2004 our institution adopted the use of fluoroquinolones (FQ) for bacterial prophylaxis in AML pts receiving HIDAC. We compared rates of hospital admission due to FN before and after the initiation of bacterial prophylaxis with FQ. We also evaluated the incidence of blood stream infections (BSI) and the incidence of resistant infections among the two groups.

We identified AML (excluding acute promyelocytic leukemia) pts receiving cytarabine-based remission induction chemotherapy at Cleveland Clinic who achieved a complete remission and then were treated with HIDAC post-remission chemotherapy (cytarabine dose of 3000mg/m² × 6) from 1997–2008. Pts receiving FQ prophylaxis with ciprofloxacin 500mg twice daily or levofloxacin 500mg once daily comprised the treatment group, while AML patients with no prophylaxis served as controls. Pts were excluded if they developed an episode of FN during hospital admission for HIDAC or received non-FQ bacterial prophylaxis. Categorical data and continuous variables were analyzed per chemotherapy cycle using Fishers exact test and independent-sample t-tests, respectively.

80 pts received HIDAC post-remission chemotherapy during the study period; 52 received FQ prophylaxis; 28 did not. A total of 198 chemotherapy cycles were administered, 148 in the FQ group and 50 in the control group. The mean age (+/−SD) of the entire cohort was 44.8 (11.4) years; 53% were female. Despite the decreased use of granulocyte-colony stimulating factor in the FQ group (12% vs. 50%, p<0.001), the duration of neutropenia was the same (24.6 days vs. 23.8 days, p=0.5) between groups. All other baseline characteristics were similar. FQ treated pts had a 33% absolute reduction in hospital admissions due to FN (50.7% vs. 84%, p<0.001) and when admitted, hospital LOS for FN was shorter for the FQ group (7.9 days vs. 10.5 days, p=0.007). The incidence of BSI was also reduced in the FQ group (23% vs. 42%, p=0.009); however there was an increase in resistant gram-negative (5/17 vs. 0/14, p=0.04) and resistant gram-positive (15/19 vs. 3/9, p=0.03) infections among pts treated with FQ.

AML pts treated with HIDAC chemotherapy followed by FQ prophylaxis had fewer and shorter hospital admissions due to FN compared to pts with no prophylaxis. FQ treated patients were at increased risk of developing antibiotic-resistant bacterial BSI.

No relevant conflicts of interest to declare.