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Antifungal — polyene (topical oral candidiasis treatment) Pregnancy: Compatible — negligible systemic absorption; topical antifungal of choice in pregnancy.

Nystatin 100,000 units/mL Oral Suspension

Brand names: Nystan

Adult dose

Dose: 1 mL (100,000 units) four times daily, held in mouth for 1 minute before swallowing
Route: Oral (oral suspension — topical mucosal contact)
Frequency: Four times daily
Max: 500,000 units four times daily (immunocompromised)
Oral candidiasis (thrush): 1 mL QDS for 7 days (retain in mouth for 1 minute before swallowing for mucosal contact — 'swish and swallow'). Continue for 48 hours after symptoms resolve. Immunocompromised or denture wearers: increase to 5 mL (500,000 units) QDS. Dentures: soak in nystatin suspension overnight; leave out during treatment if possible.

Paediatric dose

Route: Oral
Frequency: Four times daily
Max: 100,000 units per dose
Concentration: 100000 units/ml
Neonates (oral thrush): 100,000 units (1 mL) QDS — drop 0.5 mL into each side of mouth after feeds. Infants and children: 100,000 units (1 mL) QDS (or 1 mL per side of mouth). Continue for 48 hours after resolution.

Dose adjustments

Renal

No adjustment required — negligible systemic absorption.

Hepatic

No adjustment required — negligible systemic absorption.

Clinical pearls

  • First-line treatment for oral candidiasis in non-immunocompromised patients
  • Retain in mouth as long as possible before swallowing — mucosal contact time is key to efficacy
  • Denture wearers: must soak dentures overnight in nystatin solution and clean prosthetics during treatment to prevent reinfection
  • Fluconazole oral 150 mg single dose (or 50 mg/day × 7–14 days) is alternative for nystatin-refractory or immunocompromised patients
  • Identify and address predisposing factors: inhaled steroids (advise rinsing mouth after use), dentures, diabetes, immunosuppression, antibiotics

Contraindications

  • Hypersensitivity to nystatin

Side effects

  • Nausea, vomiting, diarrhoea (with high doses — swallowed component)
  • Oral irritation and sensitisation
  • Rash (rare — hypersensitivity)

Interactions

  • No clinically significant systemic interactions — negligible absorption

Monitoring

  • Clinical response at 5–7 days
  • Repeat cultures if not responding (consider fluconazole)

Reference: BNFc; BNF; NICE CKS Oral Candidiasis; PHE Candidiasis Guidelines; BNFc. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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