nystatine

Nystatin, also spelled nystatine, is a polyene antifungal antibiotic produced by Streptomyces noursei. It acts locally in fungal membranes by binding to ergosterol, a key component of fungal cell membranes, which disrupts membrane integrity and causes leakage of cellular contents. It is fungicidal at high concentrations and fungistatic at lower concentrations. It is poorly absorbed from the gastrointestinal tract, so oral formulations act mainly within the gut and are not used for systemic infections.

Indications and forms: Nystatin is used to treat and prevent mucosal and cutaneous candidiasis, including oral thrush, diaper dermatitis due to Candida, and vulvovaginal candidiasis. It is available in multiple forms: oral suspension (swish and swallow), tablets or capsules, topical creams, ointments, powders, as well as vaginal tablets or creams. It is not effective for systemic fungal infections due to its poor oral bioavailability.

Safety and pharmacology: Because absorption is minimal, adverse effects are usually limited to the site of application or the gastrointestinal tract. Possible gastrointestinal upset such as nausea or diarrhea with oral use; skin irritation or contact dermatitis with topical forms; rare hypersensitivity reactions. It has few drug interactions and is generally considered safe in pregnancy and lactation, though medical advice should be sought.