A study of antibiotic therapy in fever of unknown origin in neutropenic cancer patients.

Neutropenic cancer patients were given carbenicillin, cephalothin, and gentamicin (CCG) during 51 evaluable episodes of fever of unknown origin. Patients in whom fever persisted despite these antibiotics and in whom infection had not been documented were randomized after 3 days either to discontinue antibiotics or to add chloramphenicol or clindamycin to CCG. During 19 episodes (37%) an infection was documented during the first 3 days, and during an additional 12 episodes (24%) there was a response in 3 days without a focus of infection or an identifiable organism. Two patients died within 3 days, and one developed renal failure. Seventeen febrile episodes (33%) were unresponsive to CCG after 3 days and were randomized. Klebsiella was cultured in 4 of 6 patients randomized to stop antibiotics within a week of cessation, and 3 of these patients died. Of 11 episodes randomized to continue antibiotics, all patients were alive at 2 weeks after randomization and 9 after 4 weeks. This study, albeit small, demonstrates no advantage to withholding treatment in unremitting fever of unknown etiology and indeed strongly suggests that in this clinical setting, antibiotics once started should be continued until bone marrow recovery.