Types of Anti-Fungal Agents and Their Mechanism of Action

Anti-Fungal Agents

• Fenbendazole inhibits ergosterol synthesis through the inhibition of squalene oxidase.

Mode of Action

• Amphotericin B forms a complex with Ergosterol, leading to cytoplasmic leakage and fungal death.
• Echinocandins inhibit the enzyme 1,3 D-glucan synthase, thus inhibiting fungal cell wall synthesis.
• Griseofulvin disrupts fungal cell mitotic spindles, thus preventing fungal cell division.

Inhibition of Ergosterol Synthesis

• Azoles (e.g. Ketoconazole) cause the depletion of ergosterol in the fungal cell membrane by inhibiting the fungal cytochrome p450 3A –dependent C 14 demethylase.

Topical vs. Oral Administration

• Imidazoles are primarily topical, but one exception, Ketoconazole, is available as both oral and topical.

Fungal Death

• Amphotericin B causes fungal death by forming a complex with Ergosterol, leading to cytoplasmic leakage.

1,3 D-Glucan Synthase Inhibitors

• Echinocandins primarily act by inhibiting the enzyme 1,3 D-glucan synthase.

Flucytosine Mode of Action

• Flucytosine's primary MOA is to inhibit DNA synthesis by converting into a toxic metabolite that inhibits fungal RNA and DNA synthesis.

Squalene Oxidase Inhibitors

• Fenbendazole inhibits ergosterol synthesis through the inhibition of squalene oxidase.

Azole Mode of Action

• Azoles cause the depletion of ergosterol in the fungal cell membrane by inhibiting the fungal cytochrome p450 3A –dependent C 14 demethylase.

Allylamine Mode of Action

• Allylamines act as anti-fungal agents by inhibiting squalene epoxidase, a key enzyme in ergosterol synthesis.