Nystatin (Oral)

Nystatin oral is an antifungal medication which can be used to treat yeast infections in the mouth, throat or digestive system.


Nystatin in primarily used to treat infections of the Candida family of fungi, such as thrush. The Candida fungi occur naturally in the mouth and in the digestive system. However, in some situations the fungi can multiply rapidly, leading to infections and unpleasant symptoms.

Fungal cells are protected by a membrane which is partly made up of a substance called ergosterol. Nystatin binds with ergosterol, which damages the membrane. Without its protective layer, the fungal cell quickly dies off as the essential parts of the cell leak out.

The medication does not absorb through into the bloodstream, and so when delivered orally it can only be used to treat infections in the mouth, throat and digestive system. Its effects come through direct contact with the fungi, so when the infection is located in the mouth or throat, you should try to hold the medication in your mouth for as long as possible.

This medication is available in capsules, tablets, powder, lozenges, or as a suspension (liquid). The lozenges, powder, and liquid varieties are typically used to treat fungal infections in the mouth.

Conditions Treated

Type Of Medicine

  • Antifungal

Side Effects

Nystatin is a well-tolerated medication even when taken for extended periods of time. However, in rare cases nystatin may also produce undesired side effects in addition to the antifungal effect of the drug. These can include:

  • Diarrhea
  • Nausea and vomiting
  • Gastrointestinal disturbances
  • Oral irritation, including rashes

This is not a complete list, and medications can affect people in unexpected ways. While you are taking this medication, be aware of how you feel, and if you notice any changes that concern you, contact your doctor or pharmacist. In many cases, side effects will go away on their own as your body adjusts to the medication, but in other cases, you may be prescribed another medication to manage the side effect.


There have been no reported cases of severe toxicity in people taking large doses of nystatin, however taking excessively large doses increases the risk that you will experience side-effects, particularly irritation, nausea and gastrointestinal problems. For this reason, you should always take the medication as prescribed to do so by your doctor. If you do take an excessive dose of nystatin, contact your nearest poison control center.

Allergic reaction

Allergic reactions to nystatin are rare, but they can occur. You may also be allergic to some of the non-active ingredients in the medication, such as filler materials in tablets. You should seek emergency medical assistance if you notice any of the symptoms listed below:

  • Rives, rashes or redness on the skin
  • Itching or swelling particularly around the face, tongue, or throat
  • Dizziness, disorientation, drowsiness, or extreme fatigue
  • Any breathing problems


You will be prescribed a unique dose of nystatin that is relevant to your age and the symptoms that you are experiencing. You should therefore always take the medication exactly as your doctor prescribes. However, as a general guideline, here are the doses that are usually given:


Mix one-eighth (12.5%) of a teaspoon of the powder into four ounces of water. Stir the mixture well to ensure that the medication is fully absorbed into the water. Do not take the whole preparation at once, but instead take it in three to four portions. For each portion, move the liquid around your mouth for as long as you can, so that the medication can get to work in damaging the fungal cells. Gargle briefly before swallowing.

Lozenge or Pastille

Lozenges should be held in the mouth until they are fully dissolved. You should not chew the lozenges, or swallow them before they have dissolved.


Adults: 4 to 6 milliliters four times a day

Infants under 5 years old: 2 milliliters four times a day

Low-birth-weight or premature infants: 1 milliliters four times a day

You will usually receive a dropper which will enable you to measure your required dose. Drop the liquid into the sides of your mouth, and move it around your mouth for as long as possible. Gargle the liquid before you swallow it.

If you forget or are unable to take one of your daily doses, take the dose as soon as you can. The only exception to this is if you are near to the time at which you will take your next dose. In this case, skip the dose you missed and continue your schedule as normal. There is no need to take a double dose when you miss a previous dose, and it may be harmful for you to do so.


Nystatin is generally well-tolerated and safe to take when prescribed by a doctor. However, before you take this medication, discuss with your doctor all other medications, vitamins and over-the-counter supplements you take, to ensure that there are no adverse interactions.


Nystatin is generally considered safe for use by children, however, due to the risk of choking, children under the age of five will usually be prescribed the liquid version of the medication.

Some oral nystatin products contain sucrose or fructose, particularly the lozenge, pastille and liquid forms. This may make nystatin unsafe to take for people with certain conditions, including:

  • Diabetes
  • Fructose intolerance
  • Glucose-galactose malabsorption
  • Sucrase-isomaltase insufficiency

If you have any of these conditions, inform your doctor before you take nystatin. You will probably be prescribed a form of oral nystatin that does not contain sugar.

No studies have been carried out comparing the effects of nystatin in older individuals with the effects on younger people. If you are over the age of 65, your doctor may want to see you more often to ensure the medication is working properly.

If you have full or partial dentures, the fungal infection may reside in the dentures. You may be advised to leave your dentures in liquid nystatin overnight in order to remove the fungus from them. If you do not do this, you may reinfect yourself after your course of the medication has been completed.

Ensure that you complete the full course of your treatment as prescribed by your doctor. Do not discontinue your use of the medication early, even if your symptoms improve, or the infection may return.


Follow the guidelines below when storing your medication. If you do not do so, the strength of the medication may be affected, or it may become harmful for you to take.


The lozenge and pastille forms of oral nystatin should be kept refrigerated. If children are able to access your refrigerator, make sure the medication is kept in a child-proof container.

All other forms

Observe the following guidelines when storing the powder, tablet, capsule and liquid forms of the medication.

Store at Room temperature -- the medication may become damaged if it is exposed to excessive heat or cold. Keep the tablets at room temperature, away from heaters and radiators. The bathroom is not a suitable place to store this medication due to the heat produced by the shower and hot water faucet. Likewise, the glove compartment of your car usually gets too hot to serve as a storage location.

Dry Location -- Store your medication away from sources of moisture. The bathroom is too humid a location to store this medicine, and it should not be stored near the stove. If you are taking this medication in tablet or capsule form, remove any cotton wool from the bottle as this can cause a build up of moisture.

Avoid Sunlight -- keep the medicine well away from sources of direct sunlight, such as near windows or on the dashboard of your vehicle.

Use Child-Proof Containers -- Keep all medications away from the sight and reach of children, and always store them in child-proof containers.

Shelf Life -- Do not take the medication if it has exceeded the expiry date. In such cases the medication may not be as effective, or it may be harmful.

Safe Disposal -- when you have finished your course of treatment, do not throw any remaining medication into the trash. Instead, locate a take back scheme in your local area, who will be able to take the medication from you and dispose of it safely. Your pharmacist will advice you on where you can find a local take back scheme.


Oral nystatin is used to treat fungal infections in the mouth, throat, stomach and digestive system. It is primarily prescribed to treat Candida infections, also known as thrush. When delivered orally, nystatin does not absorb into the bloodstream and so cannot be used to treat infections in other areas of the body.

Nystatin is well-tolerated and generally does not cause any significant side effects, although some people may experience nausea or gastrointestinal upset in rare cases. It is safe to take by children and older individuals, although the dose may be adjusted.

Some oral nystatin products contain sugar, and may be unsuitable for use in people with conditions such as diabetes or fructose intolerance.