Prevention of infection in the neutropenic patient.

All adult patients with acute nonlymphocytic leukemia--either first diagnosed or in relapse--who were admitted to University Hospital (Utrecht) between 1 December 1978 and 1 November 1980 were randomly assigned to a control group or to a group that received trimethoprim-sulfamethoxazole (TMP-SMZ) prophylactically; those admitted between 30 November 1980 and 1 December 1981 received a regimen of TMP-SMZ plus colistin; those admitted from 1 December 1981 to 1 December 1983 were randomized to receive TMP-SMZ plus colistin or neomycin plus colistin; and those admitted after 1 December 1983 were randomized to receive either ciprofloxacin alone or TMP-SMZ plus colistin. All agents were capable of preventing infections. However, the use of TMP-SMZ alone led to an increase in the number of infections caused by multiresistant microorganisms. The combination of TMP-SMZ plus colistin was superior to that of neomycin plus colistin. The new quinolone derivative ciprofloxacin was more effective than TMP-SMZ and was well tolerated. Antimicrobial prophylaxis with agents that provide adequate levels of drug in tissue prevents infections in granulocytopenic patients and is superior to that with nonabsorbable agents.