Effects of fluconazole administration in critically ill patients: analysis of bacterial and fungal resistance.

HYPOTHESIS The administration of fluconazole in intensive care unit (ICU) patients leads to the emergence of bacterial and fungal resistance. DESIGN Retrospective analysis of 2 patient cohorts: (1) critically ill patients treated in surgical, trauma, and medical ICUs between June 1997 and January 1999 who did and did not receive fluconazole; and (2) ICU patients with fungal infections and sensitivity testing results from June 1994 to December 1998. SETTING University-affiliated tertiary care hospital. PATIENTS The first cohort included 99 ICU patients with documented microorganism culture(s) who were treated with (n = 50) or without (n = 49) fluconazole; the second cohort included 38 patients with Candida species infection, identification, and antifungal susceptibility testing. RESULTS Mortality (40% vs 20%; P = .03) and hospital length of stay (33.8 vs 25.6 days; P = .04) were higher in the patients treated with fluconazole compared with patients not treated with fluconazole. The ICU length of stay was also higher in patients treated with fluconazole (23.7 vs 15.1 days; P = .009). An increase in bacterial resistance occurred in patients after fluconazole treatment as opposed to bacterial resistance of patients who were treated for bacterial microorganism(s) without fluconazole (16% vs 4%; P = .049). Comparison of patient populations with Candida species identification before and after December 1997 showed an increase in Candida species resistance to fluconazole (11% vs 36%; P = .16), respectively. Fungal strains were dominated by a combination of Candida albicans and Candida glabrata in both populations (60% [before 1998] vs 82% [after 1998]), with an emergence of Candida non-albicans species tolerant to fluconazole. The amount of fluconazole administered and the number of patients receiving fluconazole treatment in the ICUs has also increased when comparing both periods. CONCLUSIONS Comparison of critically ill patient populations with and without fluconazole treatment found increased mortality and longer hospital and ICU lengths of stay in the fluconazole-treated group. This group also had higher bacterial pathogen resistance to antibiotics after fluconazole administration compared with bacterial resistance of patients without fluconazole treatment. Our results warrant concern regarding worsening bacterial infections, increased mortality, and an increase in Candida resistance to fluconazole from increased use in ICU patients, with a shift in yeast infection that is more difficult to treat.