What is the appropriate nystatin oral suspension dose and administration for a 3‑year‑old child with oral thrush?

Nystatin Dosing for Oral Thrush in a 3-Year-Old

For a 3-year-old child with oral thrush, administer nystatin oral suspension 4–6 mL (400,000–600,000 units) four times daily for 7–14 days, applied directly to the oral mucosa after meals. 1

Standard Dosing Protocol

• Nystatin suspension (100,000 units/mL): Give 4–6 mL orally four times daily 1
• Alternative formulation: Nystatin pastilles 200,000 units can be used 4–5 times daily in children old enough to dissolve them without choking risk 1
• Treatment duration: Continue for 7–14 days, even if symptoms resolve earlier to prevent relapse 1, 2

Administration Technique

• Apply the suspension directly to the affected areas of the mouth using a dropper or swab after meals and at bedtime 1
• Have the child retain the medication in the mouth as long as possible before swallowing 1
• Avoid food or drink for 30 minutes after administration to maximize contact time 2

Expected Efficacy and Limitations

• Nystatin suspension achieves clinical cure in approximately 32–54% of cases by day 12–14 3, 4
• Important caveat: Nystatin is significantly less effective than fluconazole (32% vs 100% cure rate in one pediatric trial) 3
• Relapse rates are relatively high (24–27%) within 2–4 weeks after completing nystatin therapy 5

When to Consider Alternative Therapy

For moderate to severe oral thrush or if nystatin fails after 7 days, switch to oral fluconazole 3–6 mg/kg once daily (maximum 400 mg) for 7–14 days. 1

• Fluconazole demonstrates superior efficacy (91–100% clinical cure) compared to nystatin in pediatric populations 3, 5
• The IDSA guidelines recommend fluconazole as first-line for moderate to severe oropharyngeal candidiasis 1
• Clotrimazole troches (10 mg five times daily) are an alternative for children who can safely dissolve them 1

Common Pitfalls to Avoid

• Insufficient treatment duration: Stopping therapy when symptoms improve (typically 3–5 days) rather than completing the full 7–14 day course leads to high relapse rates 2, 5
• Poor adherence to four-times-daily dosing: The frequent dosing schedule is difficult for families to maintain; consider fluconazole (once daily) if compliance is a concern 3
• Inadequate contact time: Simply swallowing the suspension without allowing mucosal contact reduces efficacy substantially 2
• Ignoring underlying risk factors: Recurrent thrush warrants evaluation for immunodeficiency, diabetes, or chronic antibiotic/corticosteroid use 1

Safety Profile

• Nystatin has excellent safety with minimal systemic absorption 1, 2
• Most common adverse effects are poor taste and mild gastrointestinal upset (nausea, diarrhea) 2, 4
• No significant drug interactions or laboratory monitoring required 2