Nystatin Oral Solution for Adult Thrush
For an adult with thrush, use nystatin oral suspension 4-6 mL (400,000-600,000 units) four times daily for 7-14 days, swishing the medication in the mouth as long as possible before swallowing. 1
Dosing and Administration
- Dose: 4-6 mL (400,000-600,000 units) four times daily 2, 1
- Duration: 7-14 days 2, 3, 4
- Technique: Place half the dose in each side of the mouth, swish thoroughly for as long as possible (ideally at least 2 minutes), then swallow rather than spit out 4, 1
- Continue treatment for at least 48 hours after symptoms resolve and cultures confirm eradication of Candida 1
Important Caveats
Nystatin is only appropriate for mild thrush. For moderate to severe disease, oral fluconazole 100-200 mg daily for 7-14 days is superior and should be used instead 2, 4. The clinical cure rates with nystatin are substantially lower (32-54%) compared to fluconazole (100%) 4, 5.
When to Use Fluconazole Instead:
- Moderate to severe symptoms 2, 4
- Immunocompromised patients 4
- Patients who cannot tolerate the frequent dosing of nystatin 6
Special Considerations
- Denture-related thrush: Disinfection of dentures is mandatory alongside nystatin treatment, as antifungal therapy alone will fail 2, 3
- HIV-infected patients: Antiretroviral therapy is strongly recommended to reduce recurrent infections 2, 3
- Recurrent infections: If thrush recurs frequently, chronic suppressive therapy with fluconazole 100 mg three times weekly may be needed 2, 4
Common Pitfalls
- Inadequate contact time: Patients must swish the suspension thoroughly and hold it in the mouth as long as possible; simply swallowing it quickly reduces efficacy 4, 1
- Premature discontinuation: Complete the full 7-14 day course even if symptoms improve earlier 4
- Using nystatin for moderate-severe disease: This is a common error; nystatin has poor efficacy in more severe cases and systemic fluconazole should be used instead 2, 4
- Ignoring dentures: Failure to disinfect dentures will lead to treatment failure and rapid recurrence 2, 3
Refractory Disease
If symptoms persist after completing nystatin treatment, consider fluconazole-refractory disease and escalate to itraconazole solution 200 mg once daily, posaconazole suspension 400 mg twice daily for 3 days then 400 mg daily, or other alternatives 2, 4.