How should I write a prescription for Nystatin oral powder for a patient with suspected oral candidiasis?

How to Write a Prescription for Nystatin Oral Suspension

For oral candidiasis, prescribe nystatin oral suspension 100,000 units/mL, with instructions to swish and swallow 4-6 mL four times daily for 7-14 days. 1

Prescription Format

Write the prescription as follows:

Nystatin Oral Suspension 100,000 units/mL

• Dispense: 60-480 mL bottle (depending on treatment duration)
• Sig: Swish and swallow 4-6 mL (400,000-600,000 units) four times daily for 7-14 days
• Instructions: Shake well before each use. Retain in mouth as long as possible before swallowing. Continue treatment for 48 hours after symptoms resolve.

2

Disease Severity-Based Dosing Algorithm

The IDSA 2016 guidelines provide clear stratification based on disease severity 1:

For Mild Oral Candidiasis:

• Nystatin suspension (100,000 U/mL): 4-6 mL four times daily for 7-14 days (strong recommendation; moderate-quality evidence)
• Alternative: Nystatin pastilles (200,000 U each): 1-2 pastilles four times daily for 7-14 days

For Moderate to Severe Disease:

• Switch to oral fluconazole 100-200 mg daily for 7-14 days (strong recommendation; high-quality evidence) 1
• Nystatin is insufficient for moderate-severe disease

For Fluconazole-Refractory Disease:

• Escalate to itraconazole solution 200 mg once daily OR posaconazole suspension 1

Key Prescribing Considerations

Formulation specifics:

• Standard concentration is 100,000 units/mL 2
• Commercial preparations contain 0.5% alcohol 2
• Available in 60 mL and 480 mL bottles 2
• Some formulations contain sugar—avoid in diabetics or consider sugar-free compounded alternatives 3

Critical instruction for patients:

• Must shake bottle vigorously before each use
• Retain medication in mouth (swish) for maximum contact time before swallowing
• Avoid eating or drinking for 30 minutes after administration
• Complete full course even if symptoms improve

Common Pitfalls to Avoid

1. Underdosing duration: Nystatin requires 7-14 days minimum. Treatment limited to symptom resolution leads to rapid recurrence 4

2. Wrong severity assessment: If patient has moderate-severe disease (extensive lesions, dysphagia, immunocompromised), nystatin will fail—start fluconazole instead 1

3. Denture-related candidiasis: Antifungal therapy alone is insufficient. Must disinfect dentures concurrently or treatment will fail 1

4. Ignoring sugar content: Standard nystatin suspensions contain sucrose. For diabetics or patients requiring prolonged therapy, request sugar-free compounded formulations 3

5. Inadequate contact time: Patients who immediately swallow the suspension get suboptimal results. Emphasize "swish and hold" technique.

Special Populations

Immunocompromised patients (HIV, chemotherapy, transplant):

• Nystatin has limited efficacy in this population
• Consider starting with fluconazole 100-200 mg daily instead 1
• If using nystatin, monitor closely for treatment failure

Infants/neonates:

• Nystatin is safe and commonly used
• Dose: 1 mL (100,000 units) to each side of mouth four times daily
• Apply directly to lesions with cotton swab or dropper 2

Recurrent infections:

• Chronic suppressive therapy with nystatin is usually unnecessary
• If required: fluconazole 100 mg three times weekly is preferred 1
• Address underlying predisposing factors (inhaled corticosteroids, dentures, xerostomia, immunosuppression)