Background: Voriconazole (Vfend®, Pfizer) is a new triazole antifungal agent with potent activity against many pathogenic fungi; however, its proper place in the treatment of fungal infections has yet to be fully defined. Methods: In order to characterize the indications for use and incidence and monitoring of adverse events, we conducted a retrospective review of all adult and pediatric voriconazole use during the first 6 months following market release. Data were collected on indication, dosing, previous and concurrent antifungal therapy, liver function test (LFT) monitoring, and concomitant use of interacting medications and management of these interactions. Results: 85 patients representing 101 distinct therapeutic courses were included. Most common underlying diseases were bone marrow transplant (50%), solid organ transplant (17%) and hematologic malignancy (22%). Aspergillus infection was the indication for 27% of treatment courses, followed by febrile neutropenia (24%) and other empiric therapy (14%). Combination therapy with systemic antifungals was used in 13 courses, 6 of which involved caspofungin. The most common drug interactions involved benzodiazepines (71% of treatment courses), calcium channel blockers (51%), tacrolimus (31%) and cyclosporine (27%). Within 72 hours of initiating voriconazole, 52% of patients receiving cyclosporine and 29% of patients receiving tacrolimus had a serum drug level outside the therapeutic range. LFTs greater than 3 times upper limit of normal were observed in about 10% of treatment courses, although no determination of causality was made. Conclusions: Voriconazole was employed for a variety of indications in its initial period of licensed use. Coprescribing of interacting drugs was frequent. Clinician awareness of voriconazole drug interactions and their management should be emphasized.
Full conference title:
43rd Interscience Conference on Antimicrobial Agents
- ICAAC 43rd