Treatment of Candida glabrata UTI
For fluconazole-resistant C. glabrata urinary tract infections, treat with amphotericin B deoxycholate 0.3–0.6 mg/kg daily for 1–7 days OR oral flucytosine 25 mg/kg four times daily for 7–10 days, and always remove the urinary catheter if present. 1
Initial Assessment and Susceptibility Testing
First, determine if the C. glabrata is fluconazole-susceptible or resistant through antifungal susceptibility testing. C. glabrata has inherently reduced susceptibility to fluconazole, making susceptibility testing critical before treatment decisions 2. Most C. glabrata isolates demonstrate fluconazole resistance, which fundamentally changes your treatment approach.
Treatment Based on Infection Site
For Cystitis (Lower UTI)
If fluconazole-susceptible (uncommon):
- Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1
If fluconazole-resistant (typical):
- Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days (strong recommendation) 1
- OR oral flucytosine 25 mg/kg four times daily for 7–10 days (strong recommendation) 1
- Consider amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) as adjunctive therapy for resistant cystitis (weak recommendation) 1
For Pyelonephritis (Upper UTI)
If fluconazole-susceptible:
- Oral fluconazole 200–400 mg (3–6 mg/kg) daily for 2 weeks 1
If fluconazole-resistant:
- Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days with or without oral flucytosine 25 mg/kg four times daily (strong recommendation) 1
- Alternative: Oral flucytosine monotherapy 25 mg/kg four times daily for 2 weeks (weak recommendation) 1
Critical Management Steps
Catheter Removal
Remove indwelling bladder catheters immediately if feasible (strong recommendation) 1. This is non-negotiable and often leads to resolution without antifungal therapy in asymptomatic patients. Catheter removal is as important as antifungal selection.
Obstruction Management
- Eliminate any urinary tract obstruction (strong recommendation) 1
- Remove or replace nephrostomy tubes and ureteral stents if present 1
- For fungus balls causing obstruction, surgical intervention is required along with antifungal therapy 1
Special Considerations
When NOT to Treat
Do not treat asymptomatic candiduria unless the patient is:
- Neutropenic
- Very low birth weight infant (<1500g)
- Undergoing urologic procedures 1
For these high-risk groups, treat as candidemia rather than isolated UTI.
Echinocandins: A Critical Limitation
Echinocandins (caspofungin, micafungin, anidulafungin) do NOT achieve adequate urinary concentrations and are not recommended by IDSA guidelines for C. glabrata UTI 3. While isolated case reports describe success 4, 5, 6, these likely represent hematogenous spread or candidemia rather than isolated UTI. The 2016 IDSA guidelines explicitly do not recommend echinocandins for urinary candidiasis despite their effectiveness for candidemia 1.
Monitoring Flucytosine Toxicity
When using flucytosine, monitor for:
- Bone marrow suppression (CBC monitoring)
- Hepatotoxicity (LFTs)
- GI toxicity
- Maintain serum levels 25-100 mcg/mL if available 2
Common Pitfalls to Avoid
- Using fluconazole empirically for C. glabrata without susceptibility testing—most isolates are resistant
- Treating asymptomatic candiduria in non-high-risk patients—this leads to resistance without benefit
- Using echinocandins for isolated UTI—they don't achieve urinary levels despite systemic efficacy
- Failing to remove catheters—medical therapy alone often fails without source control
- Inadequate treatment duration—ensure 2 weeks for cystitis, longer for pyelonephritis
Algorithm Summary
- Obtain susceptibility testing for C. glabrata isolate
- Remove catheter immediately if present
- Assess for obstruction and correct if found
- For resistant isolates (most common): Use amphotericin B deoxycholate 0.3–0.6 mg/kg daily OR flucytosine 25 mg/kg QID
- Duration: 1–7 days for cystitis with amphotericin B, 7–10 days with flucytosine, or 2 weeks for pyelonephritis
- Do not use echinocandins for isolated UTI