Initial Treatment for Fungal Pyelonephritis
For most patients with Candida pyelonephritis, oral fluconazole at a dose of 200-400 mg (3-6 mg/kg) daily for 2 weeks is the drug of choice. 1
Treatment Algorithm Based on Fungal Species
For Fluconazole-Susceptible Candida Species:
- Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1
- Consider removing any urinary tract obstruction or indwelling catheter if present 1
For Fluconazole-Resistant Candida glabrata:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days with or without oral flucytosine 25 mg/kg 4 times daily 1
- Alternative: Monotherapy with oral flucytosine 25 mg/kg 4 times daily for 2 weeks 1
- Note: Lipid formulations of amphotericin B should not be used due to low concentrations in renal tissue 1
For Candida krusei:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
Surgical and Procedural Management
- Elimination of urinary tract obstruction is strongly recommended 1
- Consider removal or replacement of nephrostomy tubes or stents if present 1
- For fungus balls: aggressive surgical debridement is central to successful treatment 1
- If percutaneous access to the renal pelvis is available, consider irrigation with amphotericin B deoxycholate at 50 mg/L of sterile water as an adjunct to systemic therapy 1
Special Considerations
Echinocandins (caspofungin, micafungin, anidulafungin):
- Not recommended as first-line therapy for Candida pyelonephritis despite in vitro activity 1
- Limitations include poor urinary concentrations and limited clinical data 1, 2
- May be considered in specific circumstances such as renal insufficiency or fluconazole-resistant organisms when other options are limited 1
Fungal Pyelonephritis with Obstruction:
- Percutaneous drainage combined with systemic and local antifungal therapy is often required 2, 3
- Systemic antifungal therapy alone may be insufficient in obstructive cases 2, 4
Common Pitfalls and Caveats
- Failure to identify and address underlying urinary tract obstruction can lead to treatment failure 2, 4
- C. glabrata accounts for approximately 20% of urine isolates in adults and often requires treatment with amphotericin B rather than fluconazole 1
- Lipid formulations of amphotericin B should be avoided due to low concentrations in renal tissue 1
- Echinocandins have poor urinary concentrations and should not be relied upon as monotherapy for fungal urinary tract infections 1, 2
- Failure to drain pus and fungal balls will likely result in treatment failure 1, 2