What is the recommended treatment for an adult patient with a yeast infection, considering their medical history and potential underlying conditions such as diabetes, immunosuppressive conditions, or previous antifungal use?

Treatment for Yeast Infection

For uncomplicated vaginal yeast infections, use a single dose of oral fluconazole 150 mg OR topical azole therapy (clotrimazole 2% cream for 3 days or miconazole 2% for 7 days), with topical agents preferred for pregnant women. 1, 2

Classification and Initial Assessment

Before initiating treatment, confirm the diagnosis with wet mount preparation using saline and 10% potassium hydroxide to demonstrate yeast or hyphae, and verify vaginal pH <4.5. 1

Uncomplicated VVC (~90% of cases):

• Mild to moderate symptoms
• Infrequent episodes (<4 per year)
• Likely Candida albicans
• Immunocompetent host 1

Complicated VVC (~10% of cases):

• Severe symptoms
• Recurrent disease (≥4 episodes/year)
• Non-albicans Candida species
• Diabetes, immunosuppression, or pregnancy 1

Treatment by Type

Uncomplicated Vaginal Yeast Infection

Oral therapy (first-line for non-pregnant patients):

• Fluconazole 150 mg single dose 1, 2
• Achieves >90% cure rate 1
• FDA-approved specifically for vaginal candidiasis 2

Topical therapy alternatives:

• Clotrimazole 2% cream: 5 grams intravaginally daily for 3 days 3
• Miconazole 2% cream: Apply intravaginally for 7 days 1, 4
• Equivalent efficacy to oral fluconazole 1
• Mandatory for pregnant women (avoid systemic azoles) 2

Complicated Vaginal Yeast Infection

For severe disease:

• Fluconazole 150 mg every 72 hours for 3 doses (total of 3 doses over 1 week) 1
• OR topical azole therapy daily for 7-14 days 1

For recurrent VVC (≥4 episodes/year):

1. Induction phase: Topical or oral azole for 10-14 days 1
2. Maintenance phase: Fluconazole 150 mg once weekly for at least 6 months 1
   • Achieves control in >90% of patients 1
   • Alternative: Clotrimazole 500 mg vaginal suppository once weekly 1
3. After cessation: Expect 40-50% recurrence rate 1

For Candida glabrata (azole-resistant):

• Topical boric acid 600 mg in gelatin capsule daily for 14 days 1
• Alternative: Compounded 17% flucytosine cream ± 3% amphotericin B cream daily for 14 days 1

Oropharyngeal Candidiasis

Mild disease:

• Clotrimazole troches 10 mg 5 times daily for 7-14 days 1
• OR miconazole mucoadhesive buccal 50 mg tablet once daily for 7-14 days 1
• Alternative: Nystatin suspension 4-6 mL (100,000 U/mL) 4 times daily for 7-14 days 1

Moderate to severe disease:

• Fluconazole 100-200 mg daily for 7-14 days 1

Fluconazole-refractory disease:

• Itraconazole solution 200 mg once daily OR posaconazole suspension 400 mg twice daily for 3 days, then 400 mg daily for up to 28 days 1
• For severe refractory cases: IV echinocandin (caspofungin 70 mg loading, then 50 mg daily; micafungin 100 mg daily; or anidulafungin 200 mg loading, then 100 mg daily) 1

Urinary Tract Candidiasis (Males)

Asymptomatic candiduria:

• Treatment generally NOT indicated unless patient is neutropenic, undergoing urologic procedures, or is a very low-birth-weight infant 5
• Remove indwelling catheters first—clears candiduria in ~50% of cases 5

Symptomatic cystitis:

• Fluconazole 200 mg daily for 2 weeks 5
• Catheter removal is mandatory 5
• For C. glabrata: Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days OR flucytosine 25 mg/kg four times daily for 7-10 days 5

Pyelonephritis:

• Fluconazole 200-400 mg daily for 2 weeks 5
• Eliminate urinary obstruction (nephrostomy tubes, stents) 5

Invasive/Systemic Candidiasis

For moderately severe to severe illness or recent azole exposure:

• Echinocandin is first-line: Caspofungin 70 mg loading dose, then 50 mg daily; OR micafungin 100 mg daily; OR anidulafungin 200 mg loading dose, then 100 mg daily 1, 6
• Initiate within 24 hours of positive blood culture—delays increase mortality 1, 6

For less critically ill patients without recent azole exposure:

• Fluconazole 800 mg loading dose, then 400 mg daily 1, 6
• Only if confirmed susceptible isolate (e.g., C. albicans) 6

Step-down therapy:

• Transition from echinocandin to fluconazole 400 mg daily when clinically stable, isolate is susceptible, and blood cultures cleared 6

Duration:

• Continue for 2 weeks after documented clearance from bloodstream AND resolution of symptoms 1, 6
• Obtain blood cultures daily or every other day until negative 1

Special Populations

Diabetes mellitus:

• Control blood glucose—best preventive measure 7
• Fluconazole 100-200 mg daily achieves 90% success rate for cutaneous/mucosal candidiasis 7
• Higher dosages (up to 800 mg daily) may be required for severe or recurrent cases 7

HIV-infected patients:

• Antiretroviral therapy strongly recommended to reduce recurrent infections 1
• Treatment regimens identical to HIV-negative patients 1
• Chronic suppressive therapy (fluconazole 100 mg 3 times weekly) only if recurrent infection despite ART 1

Pregnancy:

• Avoid oral azoles—use topical therapy only 2
• Topical azole for 7 days (longer than non-pregnant patients) 1
• If oral fluconazole used inadvertently, use contraception for 1 week after final dose 2

Immunosuppressed/neutropenic patients:

• Echinocandin or lipid formulation amphotericin B 3-5 mg/kg daily preferred 1
• Fluconazole only if no recent azole exposure and not critically ill 1

Critical Pitfalls to Avoid

• Do not treat asymptomatic candiduria in immunocompetent patients—leads to unnecessary resistance 5
• Do not delay antifungal therapy for invasive disease—initiate within 24 hours of positive blood culture 1, 6
• Do not use fluconazole for C. glabrata without susceptibility testing—high resistance rates 1, 6
• Do not use fluconazole for C. krusei—intrinsic resistance 6
• Do not prescribe oral azoles in pregnancy—teratogenic risk 2
• Failure to remove catheters significantly reduces treatment success in urinary candidiasis 5
• Do not prematurely discontinue therapy—leads to relapse, especially in disseminated disease 6