How to Write a Prescription for Nystatin Powder for Skin
For cutaneous candidiasis, prescribe nystatin topical powder 100,000 units per gram, applied to the affected area 2-3 times daily until the infection clears (typically 7-14 days). 11
Prescription Format
Write the prescription as follows:
Nystatin Topical Powder 100,000 units/gram
- Dispense: 15 grams (or 30g/60g depending on affected area size)
- Sig: Apply to affected area two to three times daily
- Duration: Continue for 7-14 days or until lesions resolve
- Refills: 0-1 as appropriate
Clinical Context and Rationale
The FDA-approved formulation contains 100,000 USP nystatin units per gram dispersed in talc 1. This is the standard concentration available commercially (marketed as Nystop® and generics) 11.
Dosing Specifics
- Frequency: 2-3 times daily application is the standard regimen 1
- Available sizes: 15g, 30g, or 60g bottles - choose based on body surface area affected 1
- Storage instructions: Room temperature 15-30°C (59-86°F); avoid excessive heat >40°C 1
Important Clinical Considerations
When Nystatin Powder is Appropriate
Nystatin powder works specifically for Candida skin infections, particularly in:
- Intertriginous areas (skin folds)
- Areas prone to moisture accumulation
- Diaper dermatitis with candidal superinfection
Critical Limitation: Nystatin Does NOT Treat Dermatophytes
A major pitfall: Nystatin has no activity against dermatophytes (tinea infections) 23. Despite this, nystatin continues to be inappropriately prescribed for tinea infections, particularly by non-dermatologists 3. If you suspect a dermatophyte infection (ringworm, athlete's foot, jock itch), use an azole (clotrimazole, miconazole) or allylamine (terbinafine) instead 2.
When to Consider Alternatives
The IDSA guidelines 44444 focus primarily on mucosal candidiasis (oral, esophageal, vulvovaginal) rather than cutaneous infections. For cutaneous candidiasis:
- Mild to moderate cutaneous candidiasis: Topical nystatin powder or azoles (clotrimazole, miconazole) are appropriate first-line options
- Severe or refractory cutaneous candidiasis: Consider oral fluconazole 100-200 mg daily
- Immunocompromised patients with extensive disease: May require systemic therapy from the outset
Special Populations
Severe burns with candidal infection: Research supports higher concentrations (up to 6,000 units/gram) mixed with other topical agents in burn units 56, but this requires specialized compounding and is beyond routine outpatient prescribing.
Practical Prescribing Tips
- Powder formulation advantages: Better for moist, intertriginous areas compared to creams or ointments
- Patient counseling: Apply to clean, dry skin; continue treatment for full course even if symptoms improve
- Follow-up: If no improvement after 7-14 days, reconsider diagnosis (may be dermatophyte, not Candida) or consider systemic therapy
- Confirm diagnosis: When possible, obtain KOH prep or fungal culture to distinguish Candida from dermatophytes before prescribing