Antimicrobial prophylaxis in hematopoietic stem cell transplant recipients: heterogeneity of current clinical practice.

Antimicrobial agents are commonly used after hematopoietic stem cell transplant (HSCT) to prevent bacterial, viral and fungal infections. A pharmacy practice survey was undertaken to evaluate prevailing practices. The 31 centers evaluated transplanted over 3400 patients in 2001. Over half used bacterial prophylaxis; all with fluoroquinolones. A significantly higher proportion (90-100%) used fungal and viral prophylaxis. Most centers used fluconazole for fungal prophylaxis, but the dose used varied from 400 mg (the recommended dose) to 100 mg. Itraconazole and amphotericin preparations were used by some centers for allograft recipients because of their activity against aspergillosis. Most centers used brief viral prophylaxis for autograft recipients aimed at preventing HSV reactivation. Viral prophylaxis for allograft recipients was usually much more prolonged, reflecting concern over cytomegalovirus infections. Overall, there was significant deviation from recommended guidelines in many of the practices. Our survey suggests that substantial variation exists among transplant centers in their approach to antimicrobial prophylaxis after HSCT. This probably stems from the lack of definitive studies and strong recommendations in several areas, availability of newer agents that have not been adequately studied in the HSCT setting, and a desire to improve outcome before definitive studies are available for newer agents, a process that could take several years.