The postantifungal effect (PAFE) of itraconazole, in comparison with those of miconazole and fluconazole, on Candida species

Abstract

To study the postantifungal effect (PAFE) of itraconazole (ITCZ) against Candida species, we quantitated it using a newly introduced parameter T/C (T=time required for the drug-treated culture to reach 5-fold increase in turbidity; C=time required for the drug-free control culture to reach 5-fold increase in turbidity) referred as PAFE index and compared the results with those obtained for two other azole antifungal drugs fluconazole (FLCZ) and miconazole (MCZ). The mean values of PAFE index for ITCZ against three C. albicans strains were 1.28, 1.45, and 1.60 when exposed to the drug for 1 hr at concentrations of 1xMIC, 2xMIC and 4xMIC, respectively. These values are similar to those for MCZ and appreciably higher than those for FLCZ. PAFE index values for ITCZ against each single strain of three non-albicans Candida species exposed to 2xMIC of the drug for 1 hr were: 1.22 with C. glabrata, 1.63 with C. parapsilosis, and 3.90 with C. tropicalis. Again, comparable values were obtained for MCZ and lower values for FLCZ. The drug concentration for exposure and the duration of exposure only slightly or scarcely affected the PAFE of ITCZ, although the magnitude of the PAFE considerably varied among different strains or species tested. In general, ITCZ, as well as MCZ, produced greater extents of PAFE than those for FLCZ against C. albicans and several non-albicans Candida species.