Itraconazole is used to treat yeast infections of the mouth and throat or of the esophagus. Itraconazole is in a class of antifungals called triazoles. It works by slowing the growth of fungi that cause infection. Itraconazole acts by inhibiting the fungal cytochrome P-450 dependent enzyme lanosterol 14-α-demethylase. When this enzyme is inhibited it blocks the conversion of lanosterol to ergosterol, which disrupts fungal cell membrane synthesis.