Fluconazole concentrations in human serum and mixed saliva after administration of fosfluconazole

The concentrations of fluconazole (FLCZ) in serum and mixed saliva after a single intravenous bolus injection of fosfluconazole (504.5mg) were determined by the paper disc method. The samples of serum and mixed saliva were obtained 0.5, 1, 2, 4, 8, and 24 hours after administration. The peak concentrations of FLCZ in serum and mixed saliva occurred 4 hours after administration of fosfluconazole and were 9.45±1.53 and 9.51±2.16μg/ml, respectively. The ratio of the mean concentration ratio of FLCZ in mixed saliva to that in serum was 0.97±0.17. The highest ratio (1.06) was noted 8 hours after administration. There was a significant correlation between the concentration of fluconazole in serum and that in mixed saliva (r=0.8466, p<0.01). A direct relation between the serum and mixed saliva concentrations of FLCZ was thus obtained. The saliva concentration was similar to the serum concentration, indicating that the saliva concentration is a reliable variable for therapeutic drug monitoring (TDM).