Antibiotic prophylaxis in neutropenic patients: new evidence, practical decisions.

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. 2006 American Cancer Society