The use of fluoroquinolones in neutropenic patients--analysis of adverse effects.

The fluoroquinolones have been extensively used in the neutropenic patient. When fluoroquinolone monotherapy was used as prophylaxis, frequently for extended periods, the rate of adverse effect of ciprofloxacin (6.9%) ofloxacin (11.6%) and norfloxacin (5.5%) were significantly lower than those of the comparator agents--co-trimoxazole, vancomycin and polymycin. Rash and gastrointestinal upset were the commonest adverse effects associated with the fluoroquinolones. When used as monotherapy for bacterial infections, often intravenously and in high dosages, the cumulative rate of adverse effects caused by the fluoroquinolones (12.6%) was similar to that caused by the comparator agents (10.3%), but significantly higher than reported for non-neutropenic patients (6.4%) and for prophylactic use. The main adverse events were also rashes (15.4%) and gastrointestinal upset (6.1%). When fluoroquinolones were used as therapy of bacterial infections in combination with other agents, the incidence of adverse events was 14.9%, which was similar to the comparator agents (13.5%). Adverse events were also similar except that nephrotoxicity was commonest with comparator combinations (4.0%). The data suggest that fluoroquinolone prophylaxis in neutropenic patients, even for prolonged periods, is safer than the comparator agents, but is associated with more frequent adverse events than in non-neutropenic patients. Fluoroquinolone therapy, frequently with high dosages, is associated with similar rate of adverse events as the comparator agents. When used in combination with the other antibiotics, fluoroquinolones are as safe as the comparator agents.