What is the recommended management for fungal infections?

Management of Fungal Infections

The optimal management of fungal infections requires early diagnosis and appropriate antifungal therapy based on the type of infection, causative organism, and patient factors, with echinocandins or voriconazole being first-line treatments for most invasive fungal infections. 1, 2

Diagnostic Approach

Diagnosis of fungal infections requires a combination of:

• Clinical examination: Identifying characteristic lesions or symptoms
• Laboratory testing:
  • Direct microscopy of clinical specimens
  • Fungal cultures
  • Histopathology
  • Serological tests (galactomannan, β-D-glucan)
• Radiological imaging: CT scans for invasive pulmonary infections

Treatment Algorithm by Infection Type

1. Invasive Candidiasis/Candidemia

• First-line therapy:

  • Echinocandins (caspofungin, micafungin, anidulafungin)
    • Caspofungin: 70 mg loading dose, then 50 mg daily
    • Micafungin: 100 mg daily
    • Anidulafungin: 200 mg loading dose, then 100 mg daily
  • Duration: Minimum 14 days after last positive culture and resolution of symptoms 1

• Alternative therapy:

  • Fluconazole (if isolate is susceptible)
  • Lipid formulation of amphotericin B (3-5 mg/kg/day)

2. Invasive Aspergillosis

• First-line therapy:

  • Voriconazole: 6 mg/kg IV every 12 hours for day 1, then 4 mg/kg IV every 12 hours; can switch to oral 200 mg every 12 hours 2
  • Duration: Minimum 6-12 weeks, depending on immunosuppression resolution

• Alternative therapy:

  • Lipid formulation of amphotericin B (3-5 mg/kg/day)
  • Isavuconazole

3. Mucormycosis

• First-line therapy:

  • Lipid formulation of amphotericin B (5 mg/kg/day)
  • Surgical debridement of infected tissue when feasible
  • Duration: Until resolution of clinical and radiological findings

• Alternative therapy:

  • Posaconazole (delayed-release tablets: 300 mg twice daily on day 1, then 300 mg once daily)

4. Fusariosis and Scedosporiosis

• First-line therapy:
  • Voriconazole: 6 mg/kg IV every 12 hours for day 1, then 4 mg/kg IV every 12 hours; can switch to oral 200 mg every 12 hours 1, 2
  • Duration: Until resolution of clinical and radiological findings

5. Superficial Fungal Infections

• Dermatophyte infections (tinea corporis, tinea pedis, etc.):

  • Topical azoles (miconazole, clotrimazole) or allylamines (terbinafine) for 1-4 weeks 3, 4
  • For extensive disease: Oral terbinafine or itraconazole

• Candidiasis (mucocutaneous):

  • Topical azoles for uncomplicated cases
  • Oral fluconazole for extensive or refractory cases

Special Considerations

Immunocompromised Patients

• Prophylaxis may be indicated in high-risk patients (e.g., neutropenic, transplant recipients)
• Lower threshold for empiric therapy
• Broader spectrum antifungal agents may be needed initially
• Longer duration of therapy often required 5, 6

Drug Monitoring and Adjustments

• Therapeutic drug monitoring recommended for:

  • Voriconazole
  • Posaconazole
  • Itraconazole 1

• Dose adjustments needed for:

  • Hepatic impairment
  • Renal impairment (for certain agents)
  • Drug-drug interactions

Common Pitfalls and Caveats

1. Delayed diagnosis leading to increased mortality - maintain high index of suspicion in high-risk patients
2. Inadequate source control (failure to remove infected catheters, drain abscesses, or debride necrotic tissue)
3. Insufficient duration of therapy - continue treatment until resolution of symptoms and negative cultures
4. Failure to adjust for drug interactions - azoles have numerous interactions with other medications
5. Not considering local epidemiology - resistance patterns vary by region and institution 1, 7

Follow-up and Monitoring

• Regular clinical assessment for treatment response
• Follow-up cultures to document clearance of infection
• Monitor for drug toxicity:
  • Liver function tests
  • Renal function
  • Electrolytes
• Adjust therapy based on susceptibility testing results when available

Adherence to these guidelines has been associated with improved survival rates and treatment outcomes in patients with invasive fungal infections 1.