What is the recommended treatment for Candida krusei infections?

Treatment of Candida krusei Infections

For Candida krusei infections, an echinocandin (caspofungin, micafungin, or anidulafungin), lipid formulation amphotericin B, or voriconazole should be used as first-line therapy, with echinocandins being the preferred choice for most patients. 1

Site-Specific Treatment Recommendations

Candidemia and Invasive Candidiasis

Initial Therapy Options:

• Echinocandins (preferred for most patients): 1

  • Caspofungin: 70 mg loading dose, then 50 mg daily
  • Micafungin: 100 mg daily
  • Anidulafungin: 200 mg loading dose, then 100 mg daily

• Lipid formulation amphotericin B: 3-5 mg/kg daily (effective alternative but less attractive due to toxicity potential) 1

• Voriconazole: 400 mg (6 mg/kg) twice daily for 2 doses, then 200-300 mg (3-4 mg/kg) twice daily (particularly useful when additional mold coverage is desired) 1

The 2016 IDSA guidelines provide a strong recommendation for these three options specifically for C. krusei, though the quality of evidence is low. 1 Research supports that micafungin achieves clinical cure rates of approximately 73.5% in C. krusei infections, with outcomes comparable to other echinocandins. 2

Duration of Treatment:

• Continue therapy for 2 weeks after documented clearance of Candida from the bloodstream AND resolution of symptoms AND resolution of neutropenia (if applicable) 1

Central Venous Catheter Management:

• Remove CVCs as early as possible when the catheter is the presumed source and can be safely removed 1
• Failure to remove catheters is independently associated with increased 28-day mortality 2

Urinary Tract Infections

For Cystitis (C. krusei):

• Amphotericin B deoxycholate: 0.3-0.6 mg/kg daily for 1-7 days 1
• Amphotericin B bladder irrigation: 50 mg/L sterile water daily for 5 days may be useful 1
• Remove indwelling bladder catheter if feasible (strong recommendation) 1
• Duration: 1-7 days for systemic therapy 1

For Pyelonephritis (C. krusei):

• Amphotericin B deoxycholate: 0.3-0.6 mg/kg daily for 1-7 days 1
• Eliminate urinary tract obstruction (strong recommendation) 1
• Consider removal or replacement of nephrostomy tubes or stents if present 1

For Fungus Balls:

• Surgical intervention is strongly recommended 1
• Antifungal treatment as noted above for cystitis or pyelonephritis 1
• Irrigation through nephrostomy tubes with amphotericin B deoxycholate 25-50 mg in 200-500 mL sterile water 1

Emerging evidence suggests that higher-dose micafungin (150 mg daily) may successfully eradicate symptomatic C. krusei urinary tract infections, though this is not yet guideline-recommended. 3

Special Population Considerations

Neutropenic Patients

• Echinocandins remain the preferred initial therapy (strong recommendation) 1
• Lipid formulation amphotericin B or voriconazole are acceptable alternatives 1
• Perform dilated funduscopic examination within the first week after recovery from neutropenia (not during neutropenia, as findings are minimal until recovery) 1
• Consider catheter removal on an individual basis, as gastrointestinal tract sources predominate over CVC sources in neutropenic patients 1

Patients Undergoing Urologic Procedures

• Fluconazole 400 mg (6 mg/kg) daily OR amphotericin B deoxycholate 0.3-0.6 mg/kg daily for several days before and after the procedure 1
• Note: This recommendation applies to prophylaxis; for established C. krusei infection, use amphotericin B as fluconazole is intrinsically resistant 1

Critical Clinical Pitfalls

Fluconazole Resistance:

• C. krusei exhibits intrinsic resistance to fluconazole and should never be treated with this agent 4
• This is a critical distinction from other Candida species and a common prescribing error to avoid 4

Severity Assessment:

• Echinocandins are particularly favored for moderately severe to severe illness 1
• Patient characteristics (severity of illness, neutropenia, medical admission) are independently associated with lower cure rates and should guide aggressive initial therapy 2

Monitoring:

• Obtain daily or every-other-day blood cultures until clearance is documented 5
• Initiate antifungal therapy within 24 hours of positive blood culture, as delays are associated with increased mortality 5

Step-Down Therapy Considerations

• Voriconazole can be used as step-down oral therapy for C. krusei after clinical stabilization and documented bloodstream clearance 1
• Confirm susceptibility before transitioning to any azole therapy 1
• Do not use fluconazole for step-down therapy given intrinsic resistance 4