Nystatin Dosing for Oral Thrush
For mild oral thrush, use nystatin suspension 4-6 mL (400,000-600,000 units) four times daily for 7-14 days, swishing thoroughly in the mouth before swallowing, or alternatively 1-2 nystatin pastilles (200,000 units each) four times daily for the same duration. 1, 2
Standard Dosing Regimens
The concentration of nystatin suspension is 100,000 units/mL, making the total daily dose 1.6-2.4 million units when using 4-6 mL four times daily 1, 2. The pastille alternative provides 800,000-1.6 million units daily 1, 3.
Administration technique is critical: patients must swish the suspension in the mouth for as long as possible (at least 2 minutes) to ensure contact with all affected areas, then swallow rather than spit to treat potential esophageal involvement 2. Ideally, administer after meals and before bedtime 2.
Treatment Duration and Monitoring
Continue treatment for the full 7-14 days even if symptoms improve earlier 1, 2. Extend treatment for at least 48 hours after symptoms disappear and cultures confirm eradication of Candida 2, 3.
Disease Severity Algorithm
Mild Disease
- First-line: Nystatin suspension 4-6 mL four times daily OR nystatin pastilles 1-2 (200,000 units each) four times daily for 7-14 days 1, 2
- Alternative: Clotrimazole troches 10 mg five times daily for 7-14 days 1, 2
Moderate to Severe Disease
Switch to oral fluconazole 100-200 mg daily for 7-14 days 1, 2. This is critical because fluconazole demonstrates vastly superior efficacy with 100% clinical cure rates compared to nystatin's 32-54% cure rates in comparative studies 2, 4. Nystatin is inadequate for moderate-to-severe disease 2.
Fluconazole-Refractory Disease
- Itraconazole solution 200 mg once daily 1, 2
- Posaconazole suspension 400 mg twice daily for 3 days, then 400 mg daily for up to 28 days 1, 2
- Voriconazole 200 mg twice daily 1, 2
- Amphotericin B oral suspension 100 mg/mL four times daily 1, 2
Common Pitfalls and Caveats
Nystatin has suboptimal tolerability and significantly lower efficacy compared to systemic azoles 2. In one pediatric study, nystatin achieved only 32% clinical cure versus 100% with fluconazole 2, 4. The meta-analysis confirms nystatin suspension is not superior to fluconazole in infants, children, or HIV/AIDS patients 5.
For denture-related candidiasis, denture disinfection must accompany antifungal therapy or treatment will fail 1, 2. This is a frequently missed step.
Esophageal candidiasis requires systemic therapy; topical nystatin is completely inadequate 1, 2. If dysphagia or odynophagia is present, do not use nystatin.
Enhanced Efficacy Strategies
Combining nystatin suspension and pastilles together may achieve higher cure rates than suspension alone 2, 5. The evidence suggests using both formulations simultaneously: 4-6 mL suspension plus 1-2 pastilles, both four times daily 2.
Higher pastille doses (400,000 IU) result in significantly higher mycological cure rates than 200,000 IU doses 5. Extending treatment duration to 4 weeks appears more effective than 2 weeks for pastilles 5.
Special Populations
For HIV-infected patients, antiretroviral therapy is more important than antifungal choice for reducing recurrence rates 1, 2. If chronic suppression is needed, use fluconazole 100 mg three times weekly rather than continuous nystatin 1, 2.
For patients unable to tolerate oral therapy, use intravenous fluconazole 400 mg daily or intravenous echinocandin (micafungin 150 mg daily, caspofungin 70 mg loading then 50 mg daily, or anidulafungin 200 mg daily) 2.
Safety Profile
Cutaneous hypersensitivity reactions to nystatin are rare but possible 3. The most common adverse effects are poor taste and gastrointestinal reactions 5. Patient withdrawal rates are significantly higher with nystatin suspension than clotrimazole troches due to unpleasant taste and compliance difficulties 6.