Nystatin
A polyene antifungal used as a mouth liquid, tablets or skin cream for Candida; it is barely absorbed, so it acts only locally.
Drug card
- Class
- Polyene antifungal
- How it works
- Binding ergosterol and forming pores that make the fungal membrane leak
- Used for
- Mouth and gut thrush (Candida)
- Candida skin infections, in creams
- Known for
- Nausea and vomiting
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does nystatin work?
Nystatin, made by Streptomyces noursei, binds sterols in the Candida cell membrane and makes it leaky, so the cell contents escape; it can be fungistatic or fungicidal. Taken by mouth it is barely absorbed and passes out in the stool, so it treats Candida only in the mouth and gut, or on the skin where it is applied.
Like other polyene antifungals: Polyenes bind ergosterol in the fungal cell membrane and form channels through it, so potassium, sodium and other contents leak out and the cell dies. They bind the cholesterol of human cells less strongly, but enough for amphotericin B to harm human tissue, the kidney most. Nystatin is barely absorbed from the gut, so it acts only in the mouth, gut or skin.
Uses
What is nystatin used for?
- Mouth and gut thrush (Candida)
- Candida skin infections, in creams
Side effects
Side effects of nystatin
- Nausea and vomitingKnown for
- Diarrhea
- Mouth or skin irritation where applied
- Rash or hives
- Bronchospasm or facial swelling (rare)Serious
- Stevens-Johnson syndrome (very rare)Serious
- Anaphylaxis (rare)Serious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Not for esophageal or systemic Candida infections, since almost none of the drug is absorbed.
- In kidney failure, oral doses can occasionally reach significant blood levels.
- Stop it if irritation or allergic sensitization develops.
Good to know: Unlike its relative amphotericin B, nystatin is not given IV: barely absorbed from the gut, it works only where it touches, with few side effects.
Remember it
A way to remember it
Polyenes punch pores in the fungal membrane.
Amphotericin B and nystatin bind ergosterol and line up into pores, so ions leak out and the fungus dies. They also bind some human cholesterol, which is why amphotericin B harms human cells, the kidney most.
Written for biofideX
Its class
Polyene antifungals
Other polyene antifungals with a card:
Easily mixed up with azole antifungals and allylamines.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.
Antifungals and antiparasitics
Nystatin is one of 14 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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