Nystatin
Nystatin acts locally against susceptible yeasts. Oral administration has negligible systemic absorption and is not a treatment for invasive systemic fungal disease.
Group
Polyene antifungal
Mechanism of Action
Binds fungal membrane sterols and increases membrane permeability.
Dose Rates
Birds
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Crop or gastrointestinal candidiasis | 300000–600000 IU/kg | PO | Every 12 h | Oral suspension 100,000 units/mL; local contact is essential. |
| Alternative candidiasis contact schedule | Reference only | PO | A narrative describes 300,000 IU/kg and recommends administration three times daily before feeding for local contact, while also describing twice-daily use. Resolve the intended schedule for the case; not an automatic merged regimen. | |
| Alternative enteric candidiasis regimen | 200000–300000 IU/kg | PO | Every 8–12 h | Ensure contact with oral lesions; tubing directly into the crop may bypass them. |
| Post-antibiotic candidiasis | 333333.3333333334 IU/kg | PO | Every 8–24 h | Up to 14 days; Equivalent to 1 mL of 100,000 units/mL suspension per 300 g, one to three times daily for 7–14 days. Do not gavage when mouth lesions require contact. |
| Neonatal antifungal combination during antibiotics | Reference only | PO | Every 12 h | A described mixture combines a 100 mg fluconazole tablet with 20 mL nystatin 100,000 units/mL and gives 0.5 mL/kg twice daily during antibiotic treatment. Final compounded volume/stability is not established, so no component concentration is invented. |
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Oral or gastrointestinal candidiasis | 100000 IU/animal | PO | Every 6 h | Local action requires contact with infected tissue; oral suspension is not systemic antifungal treatment. |
| Alternative oral candidiasis regimen | 50000–150000 IU/animal | PO | Every 8 h |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Oral or gastrointestinal candidiasis | 100000 IU/animal | PO | Every 6 h | Local action requires contact with infected tissue; oral suspension is not systemic antifungal treatment. |
Ratites
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Enteric candidiasis | 250000–500000 IU/kg | PO | Every 12 h |
Turtles
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Enteric yeast infection | 100000 IU/kg | PO | Every 24 h | Up to 10 days |
Reptiles
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Enteric yeast infection | 100000 IU/kg | PO | Every 24 h | General reptile listing; species-specific assessment remains necessary. |
Indications
- Local oral, crop or gastrointestinal candidiasis
- Selected topical or otic fungal infection in an appropriate formulation
Contraindications
- Hypersensitivity
- Parenteral use of oral or topical formulations
Adverse effects
- Gastrointestinal intolerance
- Poor acceptance of oral suspension
- Local irritation
Toxicity
Oral systemic toxicity is generally limited by poor absorption; assess excipients and route errors.
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Nystatin oral suspension 100,000 units/mL Shake well. Intended for local oral/GI exposure, not systemic or injectable treatment. | Oral Liquid | 100000 IU / mL | PO |
| Nystatin oral tablets 500,000 units | Tablet | 500000 IU / tablet | PO |
| Nystatin topical powder 100,000 units/g | Powder | 100000 IU / g | TOPICAL |
| Nystatin topical ointment 100,000 units/g | Other | 100000 IU / g | TOPICAL |
| Panalog nystatin combination ointment All active strengths per gram as listed. Combination treatment; do not opt into single-component dose conversion. Skin use requires a lesion-specific plan. | Other | nystatin 100000 IU / g + triamcinolone acetonide 1 mg / g + neomycin sulfate 2.5 mg / g + thiostrepton 2500 IU / g | TOPICAL |
Monitoring and Administration
Shake suspension and bring it into direct contact with infected tissue. Diagnose and correct underlying husbandry or immunosuppressive factors in birds.
The avian table lists twice-daily dosing; another narrative recommends before-feed contact three times daily. These are retained separately rather than merged into an artificial interval range.
An additional oral canine total of 22,000 units/kg/day is listed without a division schedule; it is not automatically converted into a per-administration amount.
Poultry feed treatment was described using Mycostatin-20 at 50 or 100 g product per ton for 7–10 days; product potency is required before converting to active units.
Store oral tablets and suspension tightly closed and protected from light at 15–30°C; avoid freezing the suspension or heat above 40°C.
Topical nystatin-steroid combinations may suit focal yeast lesions; use short courses and reduce frequency once controlled. Avoid eyes; neomycin may cause contact sensitization and glucocorticoids may cause skin atrophy or HPA suppression.
Historical intrauterine infusion: 250,000–1,000,000 IU in sterile water, often daily or every other day for 3–7 days. Saline causes precipitation. Evidence for dose, volume and frequency is limited; the schema lacks an intrauterine route.