Nystatin Swish and Swallow Dosing for Oral Thrush
For 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, and continue treatment for at least 48 hours after symptoms resolve with negative cultures. 1, 2
Standard Dosing Protocol
Adults and Children
- Administer 4-6 mL (400,000-600,000 units) four times daily 1, 2
- Swish the suspension in the mouth for as long as possible (at least 2 minutes) to maximize contact with affected mucosa before swallowing 3
- Place half the dose in each side of the mouth 2
Infants
- Use 2 mL (200,000 units) four times daily 2
- For premature and low birth weight infants, 1 mL four times daily is effective 2
- Use a dropper to place half the dose in each side of the mouth and avoid feeding for 5-10 minutes 2
Treatment Duration
Treat for 7-14 days minimum, extending at least 48 hours beyond symptom resolution and negative cultures confirming Candida eradication. 1, 3, 2
The 2016 IDSA guidelines provide strong recommendation with moderate-quality evidence for this duration 1. The FDA label reinforces continuing treatment until cultures demonstrate eradication 2.
Critical Timing Considerations
- Administer four times daily, ideally after meals and before bedtime 3
- This timing maximizes contact time with oral mucosa when salivary flow is reduced 3
Important Efficacy Caveat
Nystatin has significantly inferior efficacy compared to fluconazole, with clinical cure rates of only 32-54% versus fluconazole's near-100% cure rates. 3, 4
For moderate-to-severe oral thrush, oral fluconazole 100-200 mg daily for 7-14 days is superior first-line therapy with strong recommendation and high-quality evidence 1, 3. Reserve nystatin for mild disease only 1, 3.
Enhanced Efficacy Strategy
Combining nystatin suspension PLUS pastilles (1-2 pastilles of 200,000 units each, four times daily) achieves higher cure rates than suspension alone. 1, 3, 5
This combination approach for 14 days demonstrates superior clinical and mycological cure rates in descriptive studies 5. The IDSA guidelines list both formulations as equivalent alternatives, but evidence suggests synergy when used together 1, 5.
When NOT to Extend Beyond 14 Days
Do not routinely extend nystatin beyond 14 days—treatment failure indicates either moderate-severe disease requiring systemic therapy or resistant species. 3, 6
If symptoms persist after 7-14 days, this signals inadequate response requiring escalation to:
- Itraconazole solution 200 mg once daily (effective in two-thirds of fluconazole-refractory cases) 1, 3
- Posaconazole suspension 400 mg twice daily for 3 days, then 400 mg daily for up to 28 days 1, 3
- Oral fluconazole 100-200 mg daily for 7-14 days if not previously tried 1, 3
Special Populations and Adjunctive Measures
Denture-Related Candidiasis
Denture disinfection must accompany antifungal therapy—antifungals alone will fail without removing dentures at night and cleaning thoroughly. 1, 3, 6
HIV-Infected Patients
Antiretroviral therapy is more important than antifungal choice for reducing recurrence rates. 1, 3
For recurrent infections requiring chronic suppression, use fluconazole 100 mg three times weekly rather than continuous nystatin 1, 3.
Patients Unable to Tolerate Oral Therapy
For moderate-severe disease with inability to swallow, intravenous fluconazole 400 mg daily or IV echinocandin (micafungin 150 mg daily, caspofungin 70 mg loading then 50 mg daily, or anidulafungin 200 mg daily) is required 1, 3.
Common Pitfalls to Avoid
- Poor taste and gastrointestinal adverse reactions are the most common side effects limiting adherence 5
- Patients often spit out nystatin rather than swallowing it, which fails to treat potential esophageal involvement 3
- Inadequate swishing time (less than 2 minutes) reduces mucosal contact and efficacy 3
- Stopping treatment when symptoms improve rather than continuing 48 hours beyond symptom resolution leads to recurrence 2