Twenty-six oncology patients, 25 of whom received bone marrow transplants, were enrolled in a prospective, randomized, double-blinded, placebo-controlled trial assessing the efficacy of
ciprofloxacin, 750 mg p.o. b.i.d., for preventing
bacterial infections during prolonged
neutropenia. Treatment was begun within 48 hr of initiation of
chemotherapy and continued until the absolute granulocyte count recovered to greater than or equal to 500/microliters, or until the onset of
fever (greater than or equal to 38.3 degrees C). Seven evaluable subjects received
ciprofloxacin, and 11 received placebo. Risk factors for
infection were comparable in both groups.
Fever occurred in all study subjects, but onset was delayed in
ciprofloxacin recipients (median = 6 days after the fall of the absolute granulocyte count to less than or equal to 500/microliters vs. 3 days for placebo recipients, P = 0.01). No clinically or microbiologically documented
infections occurred in
ciprofloxacin recipients vs. 10
infections in placebo recipients (5
bacteremias, 4 skin/
soft tissue infections, 1
urinary tract infection, P = 0.0003).
Ciprofloxacin recipients required fewer days of therapeutic antimicrobials (median: 28
antibiotic-days vs. 49, P0.02). The bioavailability of
ciprofloxacin appeared comparable to that found in previously published studies of normal volunteers and patients not receiving
chemotherapy. Adverse effects and colonization by
ciprofloxacin-resistant microorganisms were monitored, but the sample sizes were too small to permit meaningful conclusions about these safety parameters.
Ciprofloxacin appears to be effective for preventing
bacterial infections in neutropenic patients. Additional trials are needed to establish the optimal dose of
ciprofloxacin and to compare its safety and efficacy with those of currently used prophylactic regimens.