Nystatin is a polyene ionophore antifungal used to treat cutaneous, mucocutaneous, and gastrointestinal mycotic infections, particularly those caused by Candida species. It is one of the most effective antifungal agents synthesized by bacteria, in this case a strain of Streptomyces noursei, and is closely related to amphotericin B, differing only slightly in structure. As it undergoes very little absorption following oral or topical administration, nystatin's efficacy is limited to the treatment/prevention of cutaneous, mucocutaneous, and gastrointestinal fungal infections. Nystatin is available in oral formulations for the treatment and/or prevention of oral candidiasis (a.k.a. thrush), intestinal candidiasis, and anal candidiasis. It is indicated topically for the treatment of vulvovaginal candidiasis and other cutaneous candida infections. Nystatin is a channel-forming ionophore, meaning it exerts its therapeutic effect via formation of a membrane-spanning pore in the fungal plasma membrane. The formation of this pore results in a change in membrane permeability that allows for leakage of intracellular contents and the subsequent disruption of electrochemical gradients necessary for proper cell function. Selectivity for fungal cells over mammalian cells is due to nystatin’s greater binding affinity for ergosterol, a key sterol found in fungal cell walls, as opposed to its mammalian counterpart, cholesterol.

Nystatin Pathway References