Treatment of Fungal Infections
The treatment of fungal infections should be tailored to the specific type of infection, location, and patient factors, with fluconazole being the first-line treatment for most candidal infections and voriconazole for invasive aspergillosis. 1, 2
Classification of Fungal Infections
Fungal infections can be broadly categorized into:
Superficial/Mucocutaneous Infections
- Oropharyngeal candidiasis
- Esophageal candidiasis
- Dermatophyte infections (tinea)
- Candida skin/nail infections
Invasive Fungal Infections
- Candidemia/Invasive candidiasis
- Invasive aspergillosis
- Cryptococcosis
- Zygomycosis
Treatment Approach by Infection Type
Mucocutaneous Candidiasis
Oropharyngeal Candidiasis:
- First-line: Fluconazole 100-200 mg daily for 7-14 days 1, 2
- Alternatives:
- Nystatin suspension 200,000-400,000 units QID for 7-14 days
- Itraconazole 200 mg daily
- Clotrimazole troches
Esophageal Candidiasis:
- First-line: Fluconazole 200-400 mg daily for 14-21 days 1
- Alternatives:
- Itraconazole 200 mg daily
- Voriconazole
- Echinocandins (for severe cases)
- AmB-d 0.3-0.7 mg/kg/day IV (for refractory cases)
Urinary Tract Candida Infections
Symptomatic Cystitis:
- First-line: Fluconazole 200 mg daily for 14 days 1
- Alternative: AmB-d 0.3-0.6 mg/kg/day
Pyelonephritis:
- First-line: Fluconazole 200-400 mg daily for 14 days 1
- Alternative: AmB-d with or without 5-FC for 7-14 days
Invasive Candidiasis/Candidemia
- First-line: Echinocandin (caspofungin, micafungin, anidulafungin) 1
- Step-down therapy: For stable patients with susceptible isolates (especially C. albicans), transition to fluconazole after initial response
- For C. glabrata: AmB-d 0.7-1.0 mg/kg/day or echinocandin 1
- For C. krusei: Echinocandin, L-AmB, or voriconazole 1
- Duration: Treat for 14 days after first negative blood culture and resolution of symptoms
Invasive Aspergillosis
- First-line: Voriconazole (loading dose 6 mg/kg IV q12h for 24h, then 4 mg/kg IV q12h, transition to oral 200 mg BID when stable) 2, 3
- Alternatives:
- Liposomal Amphotericin B (L-AmB)
- Echinocandin (as salvage therapy)
- Duration: Until resolution or stabilization of all clinical and radiographic manifestations 1, 2
- Special consideration: Surgical intervention for pulmonary lesions near great vessels or with hemoptysis 2
Treatment Considerations for Special Populations
Neutropenic Patients
- Empiric therapy: AmB-d 0.7-1.0 mg/kg/day IV, echinocandin, or voriconazole 1
- Duration: For candidemia, treat for 2 weeks after first negative blood culture, symptom resolution, and neutropenia resolution 1
Neonates
- First-line: AmB-d 1.0 mg/kg/day or fluconazole 12 mg/kg/day 1
- Diagnostic workup: Lumbar puncture, ophthalmoscopic examination, and imaging of genitourinary tract, liver, and spleen recommended 1
Monitoring and Follow-up
- For azole therapy: Monitor liver function tests before and during treatment
- For voriconazole: Also monitor for visual disturbances 2, 4
- For AmB formulations: Monitor renal function and electrolytes
- Follow-up cultures: Particularly important for invasive infections to confirm clearance
Common Pitfalls to Avoid
Inadequate treatment duration - Continue treatment until complete resolution of symptoms and, for invasive infections, radiographic findings 2
Overlooking drug-drug interactions - Azoles have significant interactions with many medications 2, 4
Failure to remove infected devices - Intraventricular devices in CNS candidiasis and infected catheters in candidemia should be removed when possible 1
Misdiagnosis - Obtain appropriate cultures and histopathology before initiating therapy 3
Not considering surgical intervention - Some fungal infections (especially invasive aspergillosis and zygomycosis) may require surgical debridement in addition to antifungal therapy 1, 2
By following these evidence-based guidelines and considering the specific type of fungal infection and patient factors, clinicians can optimize treatment outcomes and reduce morbidity and mortality associated with fungal infections.