Antimicrobial prophylaxis in bone marrow transplantation.

OBJECTIVE: To review the efficacy of antimicrobial prophylaxis in bone marrow transplantation. DATA SOURCES: English-language articles identified through a MEDLINE search (1975 to 1994) and through the bibliographies of selected articles. STUDY SELECTION: Articles on the use of antimicrobial agents for the prevention of infections in bone marrow transplant recipients and neutropenic patients with cancer. DATA SYNTHESIS: Use of quinolones reduces the incidence of gram-negative bacillary infections but increases the frequency of infections caused by streptococci and staphylococci before marrow engraftment. Death associated with alpha-hemolytic streptococcal bacteremia is of concern and may justify the use of penicillin for prophylaxis. Conflicting data exist regarding prophylaxis with vancomycin. Although ganciclovir has diminished the incidence of infection and disease caused by cytomegalovirus in seropositive recipients, drug-induced myelotoxicity, emergence of resistant virus, and cost are major concerns. High-dose acyclovir may suppress reactivation of cytomegalovirus. Acyclovir prevents herpes simplex virus infection, but its prolonged use to prevent reactivation of varicellazoster virus is not cost-effective and remains controversial. Fluconazole prevents colonization and infection with Candida species other than C. krusei and Torulopsis glabrata before marrow engraftment. Elevation of cyclosporine concentrations because of interaction between azoles and cyclosporine requires close monitoring of plasma drug levels. Optimal chemoprophylaxis is not available against aspergillus or fungal infections that develop after engraftment. Trimethoprim-sulfamethoxazole decreases the incidence of Pneumocystis carinii infection and "late" bacterial infections in recipients of allogeneic transplants who have chronic graft-versus-host disease.
CONCLUSION: Available antimicrobial agents can prevent common bacterial, viral, and "early" fungal infections. However, the few studies that address antimicrobial prophylaxis in bone marrow transplantation have not always shown a survival benefit. Toxicity and cost-effectiveness of prophylactic strategies should be critically evaluated.