Itraconazole capsules are used to treat fungal infections in the lungs that can spread throughout the body. Itraconazole capsules are also used to treat fungal infections of the fingernails. Itraconazole tablets and capsules are used to treat fungal infections of the toenails. Itraconazole is an antifungal medication that is used in adults to treat infections caused by fungus. This includes infections in any part of the body including the lungs, mouth or throat, toenails, or fingernails.