A number of different antifungal agents are available. Agents in use for humans and animals are sometimes used in environmental, industrial and agricultural settings, but there are agents that are useful on plants but not humans or animals.
Generally speaking, the available agents can be classified as follows:
Allylamines and other non-azole ergosterol biosynthesis inhibitors:
These agents act in a variety of fashions, but fundamentally all lead to reduced ergosterol biosynthesis and are thus conceptually related to the azole antifungal agents. One example is terbinafine, which acts by inhibiting squalene epoxidase.
Antimetabolites:
This class has only one example, flucytosine. This small molecule is a DNA substrate analog that leads to incorrect DNA synthesis.
Azoles:
There are many agents of this class now available. All inhibit the synthesis of ergosterol by blocking the action of 14-alpha-demethylase. Examples: fluconazole, itraconazole, posaconazole, voriconazole, isavuconazole
Glucan Synthase inhibitors:
Agents of this class inhibit glucan synthesis. Glucan is a key component of the fungal cell wall, and inhibition of this enzyme produces significant antifungal effects. Examples: caspofungin, micafungin, anidulafungin
Polyenes:
These very potent agents act by binding to the fungal cell membrane and causing the fungus to leak electrolytes. Examples: amphotericin B, nystatin
Miscellaneous systemic agents:
This class currently contains only one agent, griseofulvin. It acts by disrupting the mitotic spindle.