Moxifloxacin prophylaxis in neutropenic patients.

OBJECTIVES: Recent studies have shown a beneficial impact of fluoroquinolones on infection-related morbidity and mortality for patients with haematological malignancies during neutropenia. Among the fluoroquinolones moxifloxacin currently provides one of the broadest spectra of antibacterial activity and may be suitable for prophylaxis during neutropenia. PATIENTS AND METHODS: In this controlled before and after observational study, moxifloxacin chemoprophylaxis was used during prolonged neutropenia in haemato-oncological patients (period 2; 282 episodes). Data were compared with two periods with levofloxacin prophylaxis, one preceding period (period 1; 399 episodes) and a post-observational period (period 3; 53 episodes). Endpoints for evaluation were the rates of Gram-negative and Gram-positive bacteraemia and infection-related mortality. RESULTS: We found similar survival rates as compared with levofloxacin. The rate of Gram-negative bacteraemia was higher during prophylaxis with moxifloxacin (11%) when compared with levofloxacin (6% for period 1 and 6% for period 3). In addition we observed a marked increase in diarrhoea associated with Clostridium difficile toxin A (CDAD) after a formula change from levofloxacin to moxifloxacin (attack rate 6% versus 33%). A decrease was attained after changing back to levofloxacin and reinforcing hygienic measures (13%). CONCLUSIONS: During moxifloxacin prophylaxis, we observed a significantly increased incidence of Gram-negative bacteraemia and CDAD. Careful attention must be paid not to trade the particularly beneficial effects of fluoroquinolones in the neutropenic setting for such disadvantageous effects. Until further data are obtained, caution is warranted when applying fluoroquinolones with high anaerobic activity in the neutropenic setting.