What is the best treatment for oral thrush (candidiasis) on the tongue in an adult?

Treatment of Oral Thrush (Oropharyngeal Candidiasis) in Adults

Severity-Based Treatment Algorithm

For mild oral thrush, start with topical therapy using clotrimazole troches 10 mg dissolved slowly in the mouth 5 times daily for 7-14 days, or alternatively miconazole mucoadhesive buccal 50-mg tablet applied once daily to the mucosal surface over the canine fossa for 7-14 days. 1, 2

For moderate to severe disease, use oral fluconazole 100-200 mg daily for 7-14 days as first-line systemic therapy. 1, 2

Mild Disease - Topical Options

• Clotrimazole troches 10 mg dissolved slowly 5 times daily for 7-14 days are highly effective with strong evidence supporting their use 1, 2

• Miconazole mucoadhesive buccal tablet 50 mg applied once daily offers the convenience of single daily dosing with equivalent efficacy 1, 2

• Alternative topical agents include nystatin suspension (100,000 U/mL) 4-6 mL swished and swallowed 4 times daily, or nystatin pastilles (200,000 U each) 1-2 dissolved slowly 4 times daily for 7-14 days 1, 2

• Topical therapy requires patient compliance with frequent dosing (except miconazole), which can be challenging but avoids systemic drug interactions 1

Moderate to Severe Disease - Systemic Therapy

• Oral fluconazole 100-200 mg once daily for 7-14 days is the preferred systemic agent due to superior efficacy, convenience, and tolerability compared to topical therapy 1, 2

• Fluconazole demonstrates clinical response within 48-72 hours in most patients, with improvement typically seen within 5-7 days 1, 2

• The once-daily dosing significantly improves compliance compared to topical agents requiring multiple daily applications 3

Refractory or Fluconazole-Resistant Disease

When oral thrush persists after 7-14 days of appropriate fluconazole therapy, escalate to alternative azoles or other antifungal classes:

• Itraconazole oral solution 200 mg once daily for up to 28 days is effective for fluconazole-refractory cases 1, 4

• Posaconazole suspension 400 mg twice daily for 3 days, then 400 mg daily for up to 28 days provides another azole option 1, 4

• Voriconazole 200 mg twice daily serves as an additional alternative for resistant cases 1, 4

• Amphotericin B deoxycholate oral suspension 100 mg/mL 4 times daily can be used when azoles fail, though availability is limited 1, 4

• Intravenous echinocandins (caspofungin 70-mg loading dose then 50 mg daily; micafungin 100 mg daily; or anidulafungin 200-mg loading dose then 100 mg daily) are reserved for severe refractory disease 1, 4

• Intravenous amphotericin B deoxycholate 0.3 mg/kg daily represents another parenteral option for treatment failures 1, 4

Important Considerations for Refractory Cases

• Consider Candida species identification and antifungal susceptibility testing, as non-albicans species (particularly C. glabrata) may be azole-resistant and respond better to echinocandins 4

• Itraconazole solution is better absorbed than capsules and should be used preferentially 1

Special Clinical Situations

Denture-Related Candidiasis

• Disinfection of dentures is essential in addition to antifungal therapy to prevent reinfection 2

• Remove dentures at night and soak in appropriate disinfectant solution 2

HIV-Infected Patients

• Antiretroviral therapy (ART) is strongly recommended as it reduces the frequency and severity of mucosal candidiasis 1, 2

• Initial treatment follows the same severity-based algorithm as immunocompetent patients 1

• For recurrent infections requiring suppression, use fluconazole 100 mg three times weekly rather than daily therapy 1, 2, 4

• Chronic suppressive therapy is usually unnecessary once immune reconstitution occurs with effective ART 1, 2

Monitoring and Adverse Effects

• Clinical response should occur within 48-72 hours for topical therapy and within 5-7 days for systemic fluconazole 1, 2

• Short courses of topical therapy rarely cause adverse effects beyond mild local irritation or hypersensitivity reactions 1

• For azole therapy exceeding 21 days, monitor liver function tests periodically due to potential hepatotoxicity 1

• Fluconazole can cause gastrointestinal upset, including nausea, vomiting, diarrhea, and abdominal pain 1

Common Pitfalls to Avoid

• Do not use ketoconazole or itraconazole capsules as first-line therapy due to variable absorption and inferior efficacy compared to fluconazole 1

• Avoid routine prophylaxis in HIV patients, as it leads to drug-resistant species, drug interactions, and unnecessary cost without mortality benefit 1

• Do not perform endoscopy immediately for suspected esophageal involvement; a diagnostic trial of fluconazole 200-400 mg daily for 14-21 days is appropriate first 1

• Ensure adequate contact time for topical agents by having patients dissolve troches or pastilles slowly rather than chewing or swallowing them 5

• Check for drug interactions before prescribing azoles, particularly in patients on warfarin, statins, or other medications metabolized by cytochrome P450 enzymes 1