What is the dosage and treatment duration for nystatin (antifungal medication) oral suspension for oral fungal infections?

Nystatin Oral Suspension Dosing and Duration

For oral candidiasis (thrush), nystatin oral suspension should be dosed at 4-6 mL (400,000-600,000 units) four times daily for 7-14 days in adults and children, with treatment continued for at least 48 hours after symptoms resolve and cultures are negative. 1

Standard Dosing by Age Group

Infants

• 2 mL (200,000 units) four times daily 1
• Use dropper to place one-half of dose in each side of mouth 1
• Avoid feeding for 5-10 minutes after administration 1
• Premature and low birth weight infants: 1 mL four times daily is effective 1

Children and Adults

• 4-6 mL (400,000-600,000 units) four times daily 1, 2, 3
• Place one-half of dose in each side of mouth 1
• Retain in mouth as long as possible before swallowing 1, 2

Treatment Duration

• Standard duration: 7-14 days 2, 3, 1
• Minimum requirement: Continue for at least 48 hours after symptoms disappear and cultures demonstrate eradication of Candida albicans 1
• Extended duration: Treatment for 4 weeks may improve efficacy compared to 2 weeks, particularly with pastilles 4

Critical Clinical Context: When NOT to Use Nystatin

Nystatin is appropriate only for mild oral candidiasis; for moderate-to-severe disease, fluconazole 100-200 mg daily for 7-14 days is superior and should be used instead. 2, 3

Situations Where Fluconazole is Preferred:

• Moderate-to-severe oral candidiasis: Fluconazole achieves 87-100% clinical cure vs. 32-54% with nystatin 5, 6
• HIV/AIDS patients: Fluconazole provides longer disease-free intervals and fewer relapses 6
• Immunocompromised patients: Systemic therapy is more appropriate 2
• Infants with thrush: Fluconazole 3 mg/kg once daily for 7 days shows 100% cure rate vs. 32% with nystatin 5

Alternative Nystatin Formulations

Nystatin Pastilles

• 1-2 pastilles (200,000 units each) four times daily for 7-14 days 7, 2, 3
• Higher dose pastilles (400,000 IU) achieve better mycological cure rates than 200,000 IU 4
• Combination therapy: Pastilles plus suspension may be more effective than suspension alone 4

Common Pitfalls and Caveats

• Poor efficacy: Nystatin has suboptimal tolerability and lower efficacy compared to fluconazole, with clinical cure rates of only 32-54% in some populations 2
• Frequent recurrences: Symptomatic relapses occur sooner and more frequently with nystatin than with fluconazole 7
• Proper administration is critical: Patients must swish thoroughly for at least 2 minutes and swallow (not spit) to treat potential esophageal involvement 2
• Complete full course: Continue for full 7-14 days even if symptoms improve sooner 2
• Denture-related candidiasis: Denture disinfection must accompany antifungal therapy or treatment will fail 2, 3
• Clinical response expected within 48-72 hours: If no improvement, consider alternative diagnosis or resistant organisms 3

Adverse Effects

• Most common: Poor taste and gastrointestinal adverse reactions 4
• Generally well-tolerated: Serious adverse effects are rare 1

When to Switch to Alternative Therapy

If nystatin fails after 48-72 hours or disease is refractory, switch to:

• Itraconazole solution 200 mg once daily 7, 2
• Posaconazole suspension 400 mg twice daily 7, 2
• Voriconazole 200 mg twice daily 7, 2
• Amphotericin B oral suspension 100 mg/mL four times daily 2