[Clinical study on fluoroquinolone prophylaxis in neutropenia patients with acute leukemia]

To investigate the clinical benefits and the impacts on distribution and antibiotic resistance of pathogenic bacterium associated with fluoroquinolone prophylaxis during neutropenia in patients with acute leukemia.

A total of 309 infection episodes occurred in patients with acute leukemia were retrospectively analyzed. The patients admitted in ward A (group A, n = 149) received oral ofloxacin as antibacterial prophylaxis during the neutropenia phase; no antibacterial prophylaxis was administered to the patients in ward B (group B, n = 160). The influences of prophylactic ofloxacin were determined by comparative evaluation on the clinical characteristics and the microbiological profile in both groups' patients.

Almost all enrolled patients experienced severe neutropenia. The median durations of ANC (absolute neutrophil count, ANC) < 0.2 x 10(9)/L were 11 (range 0 - 43) days. The median persistence time of fever was 8(range 1 - 46) days. Prophylaxis of ofloxacin decreased the proportion of normal flora (P = 0.00). The frequency of Escherichia coli was higher in group A than group B (23.9%, 12.5%, respectively, P = 0.00). Exposure to ofloxacin didn't affect the distributions of other pathogenic bacteria. No difference in the rate of ESBL (+) Escherichia coli was discovered between ofloxacin and no ofloxacin prophylaxis groups (31.9%, 35.4%, respectively, P = 0.61). Commonly used antibiotics had similar activity against the major strains isolated from two groups. Patients who received antibacterial prophylaxis showed a lower incidence (10.7%) of upper respiratory infections/tonsillitis and a relative higher incidence (14.4%) of gastrointestinal tract infections than those without intervention measure. The prophylactic use of ofloxacin couldn't cut down the risk of septicemia. Ofloxacin prophylaxis did not display negative effect on initial clinical response (65.8% in group A, 60.6% in group B, respectively, P = 0.35) and final efficacy (96.0% in group A, 91.9% in group A, P = 0.14) to the same empirical antimicrobial treatment schemes.

The fluoroquinolone prophylaxis induces diminishing proportion of normal flora and increasing frequency of Escherichia coli in severely neutropenic patients with acute leukemia, may not influence the distribution of other bacteria. The susceptibility of main pathogens may not be affected by antibiotic prophylaxis. The fluoroquinolone don't decrease the incidence of septicemia and infection in gastrointestinal tract. Our data suggest that more prudent use of antibiotic prophylaxis may be reasonable even in patients at high-risk for developing infection.