Background: The use of fluoroquinolone prophylaxis in patients with cancer and neutropenia has failed to show a significant impact on mortality, despite its usefulness in reducing the incidence of gramnegative bacteremia. However, an increase in grampositive bacteremia and the emergence of resistant colonizing bacteria have consistently been noticed.
Objective: To determine the impact of prophylaxis with fluoroquinolones on the incidence of bacteremia and mortality in a hospital with high fluorquinolone resistance in Mexico City.
Patients: We conducted a retrospective and comparative study of patients with acute mieloid (AML) and hybrid (HL) leukemia who received or not prophylaxis with fluoroquinolones and who were attended from January 2000 to December 2003. We reviewed all pertinent clinical and laboratory data of the hematologic malignancies and the febrile episodes.
Results: A total of 108 febrile episodes of severe neutropenia occurred in 69 patients, with an incidence of 6.5 events/1000 day-patient with neutropenia. The median age was 35 +/- 18.3 years and 58% were men; 51 patients had AML (71.8%) and 20 (28.1%) HL. Prophylaxis had been given since the beginning of granulocytopenia in 46 (42.6%) febrile episodes (group 1), where as in 62 no prophylaxis was given (group 2). Of the 46 episodes with prophylaxis, 27 received ciprofloxacin 500 mg qd p.o. and 19, ciprofloxacin 500 mg qd po plus fluconazol 100 mg qd po. The median duration of prophylaxis was 8.5 days (range 1-90 days). Twenty-nine bacteremias (26.8%) were documented, with an incidence of 16.4 bacteremias/1000 day-patient with neutropenia, 12 (26%) in group 1 and 17 (27.5%) in group 2. Bacteremia was most frequently caused by gram negative organisms (18/29), being Escherichia coli (14) the most commonly isolated pathogen, with 7 episodes in each group. Eight (29.6%) of the 21 isolates in which fluoroquinolone susceptibility was tested were ciprofloxacin resistant, 3 in group 1 and 5 in group 2 (p = 0.58). Median survival of patients was 38 days in group 1 and 40 days in group 2. (p = 0.2); mortality was similar in both groups, 34% and 27%, respectively.
Conclusions: In a hospital with a high prevalence of fluoroquinolone-resistance, prophylaxis in patients with acute leukemia and severe neutropenia did not prevent febrile episodes and did not have any impact on mortality. However, there was no increase in infections caused by resistant bacteria.