Patients undergoing intensive
chemotherapy for
acute myeloid leukemia are at high risk for
bacterial infections during
therapy-related
neutropenia. However, the use of specific
antibiotic regimens for prophylaxis in afebrile neutropenic
acute myeloid leukemia patients is controversial. We report a retrospective evaluation of 172
acute myeloid leukemia patients who received 322 courses of myelosuppressive
chemotherapy and had an expected duration of
neutropenia of more than seven days. The patients were allocated to
antibiotic prophylaxis groups and treated with
colistin or
ciprofloxacin through 2 different hematologic services at our hospital, as available. The
infection rate was reduced from 88.6% to 74.2% through
antibiotic prophylaxis (vs without prophylaxis; P=0.04). A comparison of both
antibiotic drugs revealed a trend towards fewer
infections associated with
ciprofloxacin prophylaxis (69.2% vs 79.5% in the
colistin group; P=0.07), as determined by univariate analysis. This result was confirmed through multivariate analysis (OR: 0.475, 95%CI: 0.236-0.958; P=0.041). The prophylactic agents did not differ with regard to the microbiological findings (P=0.6, not significant). Of note, the use of
ciprofloxacin was significantly associated with an increased rate of
infections with pathogens that are resistant to the
antibiotic used for prophylaxis (79.5% vs 9.5% in the
colistin group; P<0.0001). The risk factors for higher
infection rates were the presence of a
central venous catheter (P<0.0001),
mucositis grade III/IV (P=0.0039), and induction/relapse courses (vs consolidation; P<0.0001). In conclusion,
ciprofloxacin prophylaxis appears to be of particular benefit during induction and relapse
chemotherapy for
acute myeloid leukemia. To prevent and control drug resistance, it may be safely replaced by
colistin during consolidation cycles of
acute myeloid leukemia therapy.