What is the recommended dose of nystatin (antifungal medication) for treating fungal infections?

Recommended Dosage of Nystatin for Fungal Infections

For treating fungal infections, nystatin should be administered as follows: for oral candidiasis in adults, use 4-6 mL (400,000-600,000 units) four times daily; for infants, use 2 mL (200,000 units) four times daily; and for premature/low birth weight infants, use 1 mL four times daily. 1

Dosing by Age Group and Condition

Oropharyngeal Candidiasis

• Adults and Children:
  • 4-6 mL (400,000-600,000 units) oral suspension four times daily 1
  • Alternative: 1-2 nystatin pastilles (200,000 units each) four times daily for 7-14 days 2
• Infants:
  • 2 mL (200,000 units) four times daily 1
  • Use dropper to place one-half of dose in each side of mouth
  • Avoid feeding for 5-10 minutes after administration
• Premature/Low Birth Weight Infants:
  • 1 mL four times daily 1, 3

Administration Technique

• Retain the suspension in the mouth as long as possible before swallowing 1
• For infants and young children, place half the dose on each side of the mouth 1
• For denture-related candidiasis, disinfection of dentures in addition to antifungal therapy is recommended 2

Treatment Duration

• Continue treatment for at least 48 hours after symptoms have disappeared and cultures demonstrate eradication of Candida 1
• For mild to moderate oropharyngeal candidiasis: 7-14 days 2
• For esophageal candidiasis: 14-21 days 2
• For diaper rash: Continue for 1-2 weeks after symptoms resolve to prevent relapse 4

Special Considerations

For Refractory Infections

If nystatin fails, consider alternative therapies:

• Fluconazole 100-200 mg daily for moderate to severe oropharyngeal candidiasis 2
• Itraconazole solution 200 mg daily or posaconazole suspension for fluconazole-refractory disease 2
• For severe cases, intravenous echinocandin or amphotericin B deoxycholate at 0.3 mg/kg daily 2

Prophylaxis in High-Risk Patients

• In very low birth weight infants: 1 mL (100,000 units/mL) every 8 hours until 1 week after extubation can significantly reduce fungal colonization and systemic infection 3
• In neutropenic patients: Higher doses (1 million units every four hours) may alter colonization patterns but have not been shown to prevent disseminated fungal infection 5

Clinical Pearls and Pitfalls

Common Pitfalls

1. Inadequate Duration: Premature discontinuation after visible symptoms disappear can lead to relapse 4
2. Improper Administration: Failure to retain medication in the mouth reduces effectiveness 1
3. Missing Concurrent Conditions: For denture-related infections, failing to disinfect dentures will lead to treatment failure 2

Monitoring

• Assess for clinical improvement within 48-72 hours of starting therapy
• For persistent symptoms despite appropriate therapy, consider:
  • Medication adherence issues
  • Resistant organisms
  • Underlying immunosuppression requiring alternative therapy

Nystatin is generally well-tolerated with minimal systemic absorption, making it particularly suitable for infants, pregnant women, and patients who cannot tolerate systemic antifungals.