BIOLOGICAL SIGNIFICANCE

It is a polyene macrolide antifungal drug, often used intravenously for systemic fungal infections. It was originally extracted from Streptomyces nodosus, a filamentous bacterium.

CLINICAL USE

The main use is in systemic fungal infections (e.g. in immunocompromised patients), and in visceral leishmaniasis. Aspergillosis, Naegleria fowleri primary amoebic meningoencephalitis, Cryptococcus infections (e.g. meningitis) and candidiasis, cryptococcosis (torulosis),

North American blastomycosis, systemic candidiasis, coccidioidomycosis, histoplasmosis, zygomycosis including mucormycosis due to susceptible species of the genera Absidia, Mucor and Rhizopus, and infections due to related susceptible species of Conidiobolus and Basidiobolus, and sporotrichosis are treated with amphotericin B.

It is also used empirically in febrile immunocompromised patients who do not respond to broad-spectrum antibiotics.

MODE OF ACTION

Amphotericin B is believed to interact with membrane sterols (ergo sterol) to produce an aggregate that forms a transmembrane channel. Intermolecular hydrogen bonding interactions among hydroxyl, carboxyl and amino groups stabilize the channel in its open form, destroying activity and allowing the cytoplasmic contents to leak out.

STRUCTURE: