What is the treatment for thrush (oral candidiasis) caused by oral amoxicillin (amoxicillin)?

Treatment of Thrush Caused by Oral Amoxicillin

For thrush (oral candidiasis) caused by oral amoxicillin, first-line treatment is fluconazole 100-200 mg daily for 7-14 days for moderate to severe cases, or nystatin suspension (100,000 U/mL) 4-6 mL four times daily for mild cases. 1, 2

Treatment Algorithm Based on Severity

Mild Oral Candidiasis

• First-line options:
  • Nystatin suspension (100,000 U/mL) 4-6 mL four times daily for 7-14 days 1
  • Nystatin pastilles (200,000 U each) 1-2 pastilles four times daily for 7-14 days 1
  • Clotrimazole troches 10 mg five times daily for 7-14 days 2
  • Miconazole mucoadhesive buccal tablet applied once daily 2

Moderate to Severe Oral Candidiasis

• First-line treatment:
  • Oral fluconazole 100-200 mg daily for 7-14 days 1, 2

Fluconazole-Refractory Disease

• Second-line options:
  • Itraconazole oral solution 200 mg once daily for up to 28 days 1, 3
    • Note: Solution should be vigorously swished in the mouth (10 mL at a time) for several seconds before swallowing 3
  • Posaconazole suspension 400 mg twice daily for 3 days, then 400 mg daily for up to 28 days 1
  • Voriconazole 200 mg twice daily 1
  • Amphotericin B deoxycholate oral suspension 100 mg/mL four times daily 1, 4

Special Considerations

Risk Factors to Address

• Discontinue amoxicillin if possible, as antibiotics disrupt normal oral flora 5, 6
• Assess for other risk factors:
  • Immunosuppression
  • Diabetes mellitus
  • Poor oral hygiene
  • Use of corticosteroid inhalers
  • Ill-fitting dentures 2

For Denture Wearers

• Disinfect dentures in addition to antifungal therapy 1
• Remove and clean dentures daily
• Leave dentures out overnight if possible 2

For Recurrent Infections

• If recurrent infections occur, consider chronic suppressive therapy with fluconazole 100 mg three times weekly 1, 2
• For HIV-infected patients, antiretroviral therapy is strongly recommended to reduce recurrent infections 1

Treatment Duration and Follow-up

• Continue treatment until all clinical signs and symptoms have resolved
• For immunocompromised patients, treatment may need to be extended to 14-21 days 2
• If no improvement after 7-14 days, obtain culture with susceptibility testing to guide therapy 2

Prevention Strategies

• Maintain good oral hygiene
• Brush teeth with a soft toothbrush twice daily
• Rinse mouth with alcohol-free mouthwash
• Maintain adequate hydration 2
• Consider probiotics to help restore normal oral flora after antibiotic therapy

Amoxicillin-induced oral candidiasis is a common side effect of antibiotic therapy due to disruption of the normal oral microbiome 5, 6. Prompt recognition and appropriate antifungal treatment based on severity will lead to rapid resolution in most cases, improving patient comfort and preventing complications.