Treatment of Oral Thrush in Adults
Oral fluconazole 100-200 mg daily for 7-14 days is the first-line treatment for uncomplicated oral thrush in adults. 1, 2
Primary Systemic Treatment
Fluconazole is superior to topical agents with cure rates of 84-100% compared to nystatin's 32-51% in head-to-head trials, and provides more durable responses with lower relapse rates. 1, 2 The Infectious Diseases Society of America (IDSA) gives this recommendation the highest level of evidence (AI rating). 1
- Dosing: Fluconazole 100-200 mg orally once daily for 7-14 days 1, 2
- Expected response: Most patients experience improvement or resolution within 7 days of initiating therapy 1
- Advantages over topicals: Symptomatic relapses occur sooner with topical therapy than with fluconazole, particularly in HIV-infected patients 2
Topical Therapy Options
While fluconazole is preferred, topical agents remain acceptable for uncomplicated initial episodes in immunocompetent patients who are not critically ill: 1, 2
- Clotrimazole troches: 10 mg dissolved slowly in mouth 5 times daily for 7-14 days 1
- Nystatin suspension: 200,000-400,000 units swished and swallowed 4 times daily for 7-14 days 1
- Miconazole mucoadhesive tablets: 50 mg applied once daily to upper gum 1
Critical caveat: Both topical and systemic therapy can lead to resistance development, so the choice should not be based on resistance concerns alone. 2
Second-Line Treatment for Refractory Disease
If symptoms persist after 7-14 days of fluconazole, or if fluconazole-resistant Candida is suspected:
Itraconazole oral solution: 200 mg once daily for 7-14 days (64-80% response rate in fluconazole-refractory disease) 1, 2, 3
Voriconazole: 200 mg (3 mg/kg) orally twice daily for 7-14 days 1
Posaconazole: 400 mg twice daily (oral suspension) OR 300 mg once daily (extended-release tablets) 1
Severe Cases Requiring Parenteral Therapy
For patients unable to tolerate oral therapy or with severe disease:
- Echinocandins (caspofungin, micafungin, anidulafungin) are highly effective alternatives 1
- Amphotericin B deoxycholate: 0.3 mg/kg daily—less preferred due to toxicity 1
Special Populations and Considerations
HIV-Infected Patients
- Antiretroviral therapy (ART) is essential as adjunctive treatment and dramatically reduces the incidence of oropharyngeal candidiasis 1, 2
- For recurrent infections despite treatment, chronic suppressive therapy with fluconazole 100-200 mg three times weekly is recommended 1
Prolonged Treatment Failure (>2 months)
Before escalating therapy, evaluate for: 2
- Immunocompromised state (HIV, diabetes, corticosteroid use, chemotherapy)
- Denture-related disease requiring thorough denture disinfection
- Non-albicans Candida species or azole-resistant strains
Monitoring
- Periodic monitoring of liver chemistry studies should be considered for patients on prolonged azole therapy (>21 days) 1
Critical Pitfalls to Avoid
Do NOT use topical therapy for esophageal candidiasis—if the patient has severe throat pain with painful swallowing, this suggests esophageal involvement requiring systemic therapy at higher doses (fluconazole 200-400 mg daily for 14-21 days) 2
Do NOT use ketoconazole or itraconazole capsules as alternatives to fluconazole—they have variable absorption and are less effective 2
Do NOT overlook dentures—denture-related candidiasis requires disinfection of the prosthesis for definitive cure 2
Do NOT assume topicals are "safer" to avoid resistance—resistance develops with both topical and systemic therapy 2
Alternative Evidence: Single-Dose Regimen
One prospective study in palliative care patients demonstrated that single-dose fluconazole 150 mg resulted in >50% improvement in 96.5% of patients with advanced cancer, with significant reduction in both number and severity of symptoms by days 3-5. 4 However, this approach is not included in current IDSA guidelines and should be reserved for palliative care settings where pill burden is a primary concern.