Nystacid Oral is a nystatin suspension containing 100,000 units per ml. It is an antifungal used to treat and prevent oral thrush — a Candida infection of the mouth and throat — and Candida in the gut. It is swished around the mouth before swallowing, and is not absorbed into the body.
What is Nystacid Oral?
Nystacid is registered in South Africa in two forms:
| Product | Contains | Schedule |
|---|---|---|
| Nystacid Oral suspension | Nystatin 100,000 units/ml | S2 |
| Nystacid ointment | Nystatin 100,000 units/g | S1 |
Check which you have — the oral suspension is for the mouth and gut; the ointment is for skin.
Nystatin is a polyene antifungal. It binds to ergosterol, a component of fungal cell membranes that human cells do not have. Binding punches pores in the membrane so the cell’s contents leak out and the fungus dies. That difference in membrane composition is what makes it selective.
Nystatin’s defining feature is that it is not absorbed from the gut. Essentially all of it passes through and out in the stool. Two consequences follow, and they explain everything about how it is used:
- It works only where it physically touches. It treats Candida on the surfaces of the mouth, throat and gut — and nothing beyond. It cannot treat a vaginal, skin or bloodstream fungal infection when taken by mouth.
- It is very safe, because nothing meaningful enters the bloodstream. Side effects are minimal and it is suitable for infants.
How you take it matters more than usual. Because it works by contact, the suspension should be held in the mouth and swished around for as long as possible before swallowing, with food and drink avoided for a period afterwards. Swallowing it straight down treats the gut but barely treats the mouth — a common reason it appears not to work.
What is Nystacid Oral commonly used for?
- Oral thrush (oral candidiasis) — white patches on the tongue, inner cheeks or palate, sometimes with soreness or altered taste. The main use.
- Oral thrush in babies, a common and generally straightforward problem.
- Denture-related thrush, alongside proper denture cleaning.
- Angular cheilitis, cracking at the corners of the mouth where Candida is involved.
- Intestinal candidiasis.
- Oesophageal candidiasis, in some cases, though systemic antifungals are usually needed.
- Preventing thrush in people at higher risk — on chemotherapy, long-term steroids, or with weakened immunity.
Certain groups are much more prone to oral thrush, and the cause often matters more than the treatment:
- People using inhaled corticosteroids for asthma or COPD. This is common and largely preventable — rinsing the mouth and gargling after each inhaler dose, and using a spacer, substantially reduces it.
- Denture wearers, particularly where dentures are worn overnight.
- Babies, whose immune systems are still developing.
- People with diabetes, especially with poor blood sugar control.
- People taking antibiotics, which disturb the normal balance of organisms.
- People with dry mouth, from medicines or medical conditions.
- People with weakened immunity, including from HIV or chemotherapy.
How Nystacid Oral fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Polyene antifungals (topical) | Nystatin (Nystacid, Candacide) | Surface Candida in mouth and gut |
| Azole antifungals (topical) | Clotrimazole, miconazole | Skin, vaginal and oral thrush |
| Azole antifungals (systemic) | Fluconazole, itraconazole | Absorbed; treat infection throughout the body |
| Antibiotics | Amoxicillin, metronidazole | Bacteria only — can trigger thrush |
| Antispasmodics | Hyoscine | Gut cramping; unrelated to fungal infection |
| Anti-nausea | Metoclopramide | Nausea and vomiting |
Antibiotics have no effect on thrush and often cause it, by removing the bacteria that normally keep Candida in check. See the digestive and stomach medicines hub.
What to check before using Nystacid Oral
Use it after food, not before, so it is not immediately washed away — and avoid eating or drinking for a period afterwards.
Hold it in the mouth and swish it around before swallowing. For a baby, apply it to the affected areas with a clean finger or applicator as directed.
Continue for at least 48 hours after symptoms clear. Stopping the moment the white patches disappear is the most common reason thrush returns, as the organism is often still present.
Shake the bottle well before each dose and use the measuring device supplied.
Speak to a pharmacist or doctor first if you:
- Are treating a baby, particularly a newborn.
- Are breastfeeding. Thrush passes between mother and baby, so both usually need treating at the same time, or it bounces back and forth. Nipple pain during and after feeds is the typical sign.
- Wear dentures. These must be cleaned and soaked properly and left out overnight, or they reinfect the mouth.
- Use a steroid inhaler, so technique and rinsing can be checked.
- Have diabetes, or have not had blood sugar checked recently.
- Have recurrent thrush, or thrush without an obvious cause.
- Have a weakened immune system.
- Have difficulty or pain on swallowing, which may indicate the infection extends into the oesophagus and needs systemic treatment.
Possible cautions and when to ask a pharmacist or doctor
Nystatin is very well tolerated because it is not absorbed. Occasional effects are nausea, an unpleasant taste, mild stomach upset and, at higher doses, diarrhoea.
Stop and seek advice if you develop:
- A rash, or swelling of the face, lips or tongue.
- Blistering or peeling skin, which is rare but needs immediate attention.
- Worsening mouth soreness, or new ulcers.
See a doctor rather than continuing if:
- The thrush does not improve within about a week, or keeps returning.
- You have pain or difficulty swallowing, or a feeling of food sticking.
- You have white patches that do not scrape off, or a persistent white or red patch — not every white patch in the mouth is thrush, and a persistent one needs examination.
- You have unexplained mouth ulcers lasting more than three weeks.
- Thrush occurs without an obvious cause in an otherwise healthy adult. Recurrent unexplained oral thrush can indicate undiagnosed diabetes or immune problems including HIV, and is worth investigating.
- A baby is not feeding, or is losing weight.
- You have fever or feel generally unwell.
Addressing the cause usually matters more than the antifungal itself — inhaler technique, denture hygiene, blood sugar control, or treating mother and baby together.
Related medicine guides
Frequently asked questions
What is Nystacid Oral suspension used for? Treating and preventing oral thrush — a Candida infection of the mouth and throat — and Candida in the gut. It contains nystatin.
Is it an antibiotic? No, it is an antifungal. Antibiotics treat bacteria and often cause thrush rather than treating it.
How should I take it? After food, held in the mouth and swished around before swallowing, avoiding food and drink for a period afterwards.
Can I use it for vaginal thrush? No. Nystatin taken by mouth is not absorbed, so it cannot treat infection elsewhere. Vaginal thrush needs a local or systemic antifungal.
Can I give it to my baby? It is commonly used in infants, but ask a pharmacist or doctor first. If you are breastfeeding, you will usually both need treating.
What is the difference between the oral suspension and the ointment? The suspension treats the mouth and gut; the ointment treats skin. They are not interchangeable.
How long should I use it? Continue for at least 48 hours after symptoms clear — stopping too early is the main reason thrush returns.
Why do I keep getting thrush? Common causes include steroid inhalers without rinsing, dentures worn overnight, antibiotics, dry mouth and diabetes. Recurrent unexplained thrush should be investigated.