Nystatin

Nystatin is a polyene antifungal drug that has broad-spectrum fungicidal and fungistatic activity against a number of yeasts and fungi, most notably 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. Nystatin has a greater antifungal activity than amphotericin B - parenterally administered nystatin, however, is associated with significant toxicity and is not available in a formulation appropriate for systemic use. 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. A combination product containing nystatin alongside neomycin, gramicidin D, and triamcinolone (Viaderm K.C.®) is indicated in the treatment of corticosteroid-responsive dermatoses caused by bacterial or candidal infections and for pruritus ani/vulvae. It is also available in combination with metronidazole for the treatment of mixed infections due to Trichomonas vaginalis and Candida albicans.

Nystatin is also sometimes used off-label for the prevention of invasive candidiasis in low birth weight neonates, though it is generally reserved as a second-line option after fluconazole.