What is the recommended treatment for a patient with a fungal infection?

Treatment of Fungal Infections

The recommended treatment for fungal infections depends on the specific type of infection, site of infection, and patient factors, with echinocandins being the first-line therapy for invasive candidiasis and voriconazole for invasive aspergillosis. 1, 2

Treatment Algorithm Based on Fungal Type

Candida Infections

Invasive Candidiasis/Candidemia

• First-line therapy:
  • Echinocandins (preferred for moderate to severe illness or recent azole exposure) 1
    • Caspofungin: 70 mg loading dose, then 50 mg daily
    • Micafungin: 100 mg daily
    • Anidulafungin: 200 mg loading dose, then 100 mg daily
  • Fluconazole (for non-critically ill patients unlikely to have resistant species): 800 mg loading dose, then 400 mg daily 1
• Duration: At least 14 days after documented clearance of Candida from bloodstream and resolution of symptoms 1
• Source control: Catheter removal should be considered on an individual basis 1
• Monitoring: Follow-up blood cultures after 48-72 hours of therapy and then every other day 1

Esophageal Candidiasis

• First-line: Fluconazole 200-400 mg/day 1
• Alternatives: Itraconazole 200 mg/day, echinocandin, or voriconazole 1
• Duration: 14-21 days until clinical improvement 1

CNS Candidiasis

• First-line: Liposomal Amphotericin B (5 mg/kg daily) with or without flucytosine 1
• Step-down therapy: Fluconazole 400-800 mg (6-12 mg/kg) daily after initial response 1
• Duration: Until all signs, symptoms, and CSF/radiological abnormalities have resolved 1
• Device management: Infected CNS devices should be removed if possible 1

Candida Endophthalmitis

• Treatment options: Amphotericin B with flucytosine, fluconazole, liposomal AmB, voriconazole, or echinocandin 1
• Additional intervention: Intravitreal injection of amphotericin B or voriconazole for macular involvement or vitritis 1
• Duration: At least 4-6 weeks or until resolution of lesions 1

Urinary Tract Infections

• Asymptomatic cystitis: Therapy not usually needed except in high-risk patients 1
• Symptomatic cystitis: Fluconazole 200 mg (3 mg/kg) daily for 14 days 1
• Pyelonephritis: Fluconazole 200-400 mg (3-6 mg/kg) daily for 14 days 1

Mucocutaneous Candidiasis

• Oropharyngeal: Nystatin suspension, fluconazole 100-200 mg/day, or itraconazole 200 mg/day for 7-14 days 1

Aspergillus Infections

Invasive Aspergillosis

• First-line: Voriconazole (6 mg/kg IV every 12 hours for first 24 hours, then 4 mg/kg every 12 hours; oral: 200 mg every 12 hours) 1, 3
• Alternatives: Liposomal Amphotericin B, echinocandin, itraconazole 1
• Duration: Until resolution or stabilization of clinical and radiographic manifestations 1
• Surgical intervention: Consider for specific cases (pulmonary lesions near great vessels, chest wall invasion) 1

CNS Aspergillosis

• First-line: Voriconazole 1
• Alternatives: Amphotericin B, echinocandin, liposomal AmB, itraconazole 1
• Surgical intervention: Resection of infected tissue if possible 1

Other Fungal Infections

Zygomycosis

• First-line: Liposomal Amphotericin B 1
• Surgical intervention: Aggressive surgical resection is mandatory 1

Scedosporiosis and Fusariosis

• First-line: Voriconazole (6 mg/kg IV every 12 hours for first 24 hours, then 4 mg/kg every 12 hours; oral: 200 mg every 12 hours) 3

Special Considerations

Fungal Joint Infections

• First-line: Echinocandins 2
• Alternatives: Lipid formulation amphotericin B (3-5 mg/kg daily) 2
• Duration: At least 6-12 months 2
• Surgical management: Adequate drainage is critical, particularly for Candida arthritis of the hip 2

Pregnancy

• First-line: Amphotericin B deoxycholate is the treatment of choice 1

Children

• First-line: Fluconazole 8-12 mg/kg/day orally 2

Important Caveats and Pitfalls

1. Resistance concerns:

   • Candida krusei is intrinsically resistant to fluconazole 4, 5
   • Candida glabrata often shows reduced susceptibility to azoles 4, 5
   • Monotherapy with flucytosine should be avoided as resistance develops rapidly 1

2. Diagnostic considerations:

   • Obtain specimens for fungal culture before starting therapy 3
   • Testing for antifungal susceptibility should be considered for treatment failures or prior antifungal exposure 1
   • Superficial wound swabs are not reliable for determining true infection versus colonization 2

3. Treatment modifications:

   • For patients with moderate to severe illness, favor echinocandins 1
   • For non-critically ill patients unlikely to have resistant species, fluconazole is appropriate 1
   • Adjust dosing for renal insufficiency with fluconazole 6
   • Consider drug interactions, particularly with voriconazole 3

4. Follow-up:

   • Regular monitoring of clinical response and inflammatory markers is essential 2
   • Adjust therapy based on culture results and clinical response 3

By following this evidence-based approach to fungal infection management, clinicians can optimize outcomes while minimizing treatment failures and resistance development.