Background. Enteral fluconazole, a triazole antifungal agent with an excellent oral bioavailability, has not been widely studied in critically ill surgical patients. Methods. During a randomized placebo-controlled trial of enteral fluconazole (N = 130) versus placebo (N = 130) for the prevention of fungal infections in critically ill surgical patients, trough fluconazole levels were measured after the loading dose and 3 times weekly during intensive care unit stay. Minimum inhibitory concentrations (MICs) for fluconazole were measured on all infecting Candida isolates. Results. Four hundred sixty-seven serum samples were assayed for fluconazole levels in 121 patients. The most common infecting fungal species was Candida albicans, isolated in 14 of 31 infections (45%). Other infecting species were C glabrata, C tropicalis, and C parapsilosis. Mean fluconazole levels were above the highest MIC for C albicans and C parapsilosis in all but 5 patients (4%). Mean fluconazole levels were below the median MIC for C glabrata in 93 of 121 patients (77%). No significant relationship was seen between fluconazole levels and risk for fungal infection. Conclusions. Serum fluconazole levels are above the MIC of most yeast species found in these patients. These levels may not be above the MIC of C glabrata, the second most common Candida isolate causing infection in this study.
ASJC Scopus subject areas