Generic Name: nystatin
Brand Names: Mycostatin, Nilstat, Nyamyc, Nystat Rx, Nystatin Systemic, Nystex
Drug Class: Antifungals, Other; Antifungals, Systemic
What is nystatin, and what is it used for?
Nystatin is an antifungal medication used to treat yeast and fungal infections, in particular those caused by Candida species (candidiasis).
Oral nystatin is used in the treatment of mouth and throat (oropharyngeal), and intestinal fungal infections. Nystatin is also available as topical applications for skin and vaginal yeast infections.
Nystatin is not well absorbed with oral or topical administration and it is effective only for fungal infections on the skin, and the mucous lining of the mouth, throat and gastrointestinal tract.
Nystatin is an ionophore that dissolves in the fungal cell membrane and increases the membrane’s permeability. This results in leakage of fungal cell contents and destruction of the fungus. Nystatin binds to ergosterol, a sterol in the fungal cell membrane that functions similar to cholesterol in humans. Nystatin is not absorbed systemically by humans and oral nystatin is excreted unchanged in the stools.
Nystatin is used off-label for the prevention of secondary fungal infection associated with peritoneal dialysis, concurrently with antibacterial drugs to prevent bacterial infections. Nystatin has an orphan designation being investigated for use in invasive fungal infections.
Warnings
- Do not use if you are hypersensitive to nystatin or any of its components.
- Do not use nystatin to treat systemic fungal infections.
- Stop using nystatin if you notice irritation or sensitization after using nystatin.
What are the side effects of nystatin?
Common side effects of nystatin include:
- Oral irritation and sensitivity
- Diarrhea
- Nausea
- Vomiting
- Stomach pain
- Gastrointestinal disturbances
Rare side effects of nystatin include:
- Bloody diarrhea
- Muscle pain (myalgia)
- Skin reactions including:
- Rash
- Hives (urticaria)
- Stevens-Johnson syndrome
- Contact dermatitis
- Hypersensitivity reactions including:
- Rapid heart rate (tachycardia
- Bronchospasm
- Facial swelling
Seek medical care or call 911 at once if you have the following serious side effects while using this drug:
Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:
- Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
- Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
- Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
- Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.
What are the dosages of nystatin?
Oral Powder
- 100,000 units/g
Oral Suspension
- 100,000 units/mL
Oral Tablet
- 500,000 units
Capsule
- 500,000 units
- 1,000,000 units
Adult:
Oropharyngeal Candidiasis
- Oral suspension: 400,000-600,000 units orally every 6 hours; swish in mouth several minutes and then swallow
Intestinal Candidiasis
- Oral tablets: 500,000-1,000,000 units every 8 hours
- Powder: 1/8 to 1/4 teaspoonful in 1/2 cup of water (500,000-1,000,000 units) orally every 8 hours
Administration
- Retain suspension in mouth as long as possible before swallowing
Pediatric:
Oropharyngeal Candidiasis
Premature infants
- 100,000 units orally every 6 hours; paint suspension into recesses of the mouth
Infants
- 200,000 units orally every 6 hours (100,000 units in each side of mouth); paint suspension into recesses of the mouth
Children
- Oral suspension: 400,000-600,000 units PO orally every 6 hours; swish in mouth several minutes and then swallow
Intestinal Candidiasis
- Oral tablets: 500,000 units-1,000,000 units every 8 hours
- Powder: 1/8 to 1/4 teaspoonful in 1/2 cup of water (500,000-1,000,000 units) orally every 8 hours
Overdose
- Overdose of nystatin can cause nausea and gastrointestinal upset.
- There have been no reports of serious toxicity from nystatin overdose. In case of overdose, discontinue nystatin, and if symptoms don’t resolve, seek medical help or contact Poison Control.
What drugs interact with nystatin?
Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.
- Severe interactions of nystatin include:
- allogeneic cultured keratinocytes/fibroblasts in bovine collagen
- Serious interactions of nystatin include:
- Saccharomyces boulardii
- Moderate interactions of nystatin include:
- voclosporin
- Nystatin has no known mild interactions with other drugs.
The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.
It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.
Pregnancy and breastfeeding
- There are no studies of nystatin use during pregnancy and it is not known if nystatin can affect reproductive capacity or cause fetal harm. Nystatin should be used in pregnancy only if clearly needed.
- It is not known if nystatin is present in breast milk. Many drugs are excreted in breast milk, use with caution in nursing mothers.
What else should I know about nystatin?
- Take nystatin exactly as prescribed.
- Nystatin is for treating fungal infections, do not use for viral, bacterial or protozoan infections.
- Store nystatin safely out of reach of children.

SLIDESHOW
Bacterial Infections 101: Types, Symptoms, and Treatments See SlideshowSummary
Nystatin is an antifungal medication used to treat yeast and fungal infections (mouth, throat, intestinal, and vaginal infections), in particular those caused by Candida species (candidiasis). Common side effects of nystatin include oral irritation and sensitivity, diarrhea, nausea, vomiting, stomach pain, and gastrointestinal disturbances. Nystatin should be used in pregnancy only if clearly needed. Use nystatin with caution in nursing mothers.
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Medications & Supplements
- nystatin (oral tablet and capsule)
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- Who Is A Candidate for Thrombolytic Therapy?
- nystatin oral suspension, Bio-Statin, (Mycostatin, Nilstat, and Nystex are discontinued)
- nystatin lozenge (pastille)-oral, Mycostatin
- nystatin powder suspension - oral
- neomycin-gramicidin-nystatin-triamcinolone-cream
- Side Effects of Mycostatin (nystatin)
- nystatin/metronidazole-vaginal cream
- nystatin/triamcinolone - topical, Mycolog II
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Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
https://www.rxlist.com/consumer_nystatin_mycostatin/drugs-condition.htm
https://reference.medscape.com/drug/mycostatin-nilstat-nystatin-342594#0
https://www.uptodate.com/contents/nystatin-oral-drug-information
https://www.accessdata.fda.gov/drugsatfda_docs/anda/98/64142ap_appltr_prntlbl_chemr.pdf
https://pubchem.ncbi.nlm.nih.gov/compound/Nystatin