New evidence shows that
antibiotic prophylaxis in neutropenic patients reduces mortality, febrile episodes, and
bacterial infections. For patients with acute
leukemia or those who undergo
bone marrow transplantation, prophylaxis with
fluoroquinolones diminished the risk of death from any cause by 33% (95% confidence interval [95% CI], 2-54%). Thus, 55 patients who have acute
leukemia or who undergo
bone marrow transplantation must receive prophylaxis to prevent 1 death. In 4 studies that included patients with solid
tumors or
lymphoma, prophylaxis reduced the rate of death during the first month (relative risk, 0.51; 95% CI, 0.27-0.97), and 82 patients had to receive prophylaxis to prevent 1 death. The main argument brought against prophylaxis is the induction of resistance. Patients who received prophylaxis did not experience more
infections caused by resistant strains than patients in the control group. The recent GIMEMA study was conducted in a population with a nearly 50% resistance to
fluoroquinolones in all pathogens and 20% resistance in gram-negative isolates, thus indicating that prophylaxis should be offered in settings with similar or less resistance. Prophylaxis with
fluoroquinolones was efficacious in reducing
infections caused by gram-positive bacteria. Patients who are treated for acute
leukemia should be offered prophylaxis with
ciprofloxacin or
levofloxacin. Prophylaxis to cover the expected period of
neutropenia may be considered for the first cycle of treatment in patients with solid
tumors or
lymphoma who regularly receive regimens that cause severe
neutropenia. Excessive local levels of resistance to
fluoroquinolones or high local incidence of
infections caused by Clostridium difficile and related to
fluoroquinolones should prompt a reconsideration of this policy.