What is the appropriate treatment for a symptomatic Candida glabrata urinary tract infection in a 66‑year‑old male?

Treatment of Symptomatic Candida glabrata UTI in a 66-Year-Old Male

For symptomatic Candida glabrata urinary tract infection in this patient, you must first determine fluconazole susceptibility; if the organism is fluconazole-susceptible, treat with oral fluconazole 200 mg daily for 2 weeks, but if it is fluconazole-resistant (which is common with C. glabrata), use 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. 1

Initial Critical Steps

Remove any indwelling urinary catheter immediately if present—this is mandatory and strongly recommended, as catheter removal alone resolves candiduria in nearly 50% of cases and is essential for treatment success. 1

Confirm this is true symptomatic infection rather than asymptomatic colonization by documenting urinary symptoms (dysuria, frequency, urgency, suprapubic pain) or systemic signs (fever, flank pain suggesting pyelonephritis). 1

Treatment Algorithm Based on Susceptibility Testing

For Fluconazole-Susceptible C. glabrata (Cystitis):

• Oral fluconazole 200 mg (3 mg/kg) daily for 14 days 1
• This is the preferred option when susceptibility is confirmed, as fluconazole achieves urine concentrations 10–20 times higher than serum levels 1

For Fluconazole-Resistant C. glabrata (Cystitis):

• First-line: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days 1
• Alternative: Oral flucytosine 25 mg/kg four times daily for 7–10 days (can be used as monotherapy for cystitis) 1
• Combination option: Amphotericin B deoxycholate plus flucytosine for more severe cases 1
• Bladder irrigation option: Amphotericin B deoxycholate 50 mg/L sterile water daily for 5 days (only for cystitis when systemic therapy is contraindicated; has high recurrence rates) 1

For Pyelonephritis (Upper Tract Involvement):

• Fluconazole-susceptible: Oral fluconazole 200–400 mg (3–6 mg/kg) daily for 14 days 1
• Fluconazole-resistant: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days, with or without flucytosine 25 mg/kg four times daily 1
• Eliminate any urinary tract obstruction (hydronephrosis, stones) through urologic consultation 1
• Remove or replace nephrostomy tubes/stents if present 1

Why NOT to Use Certain Agents

Do not use echinocandins (caspofungin, micafungin, anidulafungin) for C. glabrata UTI—despite their excellent activity against C. glabrata systemically, they achieve minimal urinary concentrations and are ineffective for UTIs. 2, 3, 4 While one retrospective case series suggested possible benefit in complicated cases 5, this contradicts established pharmacokinetic data and guideline recommendations.

Do not use lipid formulations of amphotericin B (liposomal amphotericin, amphotericin B lipid complex) for UTIs, as they do not achieve adequate urine levels. 6

Do not use voriconazole for C. glabrata UTI—it does not accumulate in active form in urine and should not be used for urinary candidiasis. 1

Important Clinical Considerations

C. glabrata has variable fluconazole susceptibility—many strains exhibit dose-dependent susceptibility or frank resistance, making susceptibility testing essential before choosing therapy. 1 Higher fluconazole doses (800 mg daily, 12 mg/kg) are sometimes used for susceptible C. glabrata infections, though this has not been validated in clinical trials. 1

Amphotericin B deoxycholate requires no dose adjustment for renal impairment but is nephrotoxic; monitor serum creatinine, BUN, potassium, and magnesium at least twice weekly during therapy. 6 Pre-hydration with normal saline mitigates nephrotoxicity. 6

Flucytosine requires significant dose reduction in renal impairment and should not be used as monotherapy for extended periods due to rapid resistance development. 6

Special Situations

For fungus balls causing obstruction: Antifungal therapy alone is insufficient—surgical or endoscopic removal is mandatory, combined with systemic amphotericin B therapy. 1, 6

For prostate involvement (rare): Consider longer treatment duration and agents with good prostatic penetration; fluconazole penetrates prostate tissue well when susceptible. 1

Monitoring and Follow-Up

Obtain repeat urine cultures to document clearance of infection after completing therapy. 1 Continue treatment for a full 2 weeks after symptom resolution for both cystitis and pyelonephritis. 1, 6

Common Pitfalls to Avoid

Do not treat asymptomatic candiduria in this patient unless he is neutropenic, undergoing urologic procedures, or has other high-risk features—asymptomatic colonization does not require treatment in most cases. 1, 6, 3

Do not assume all C. glabrata is fluconazole-resistant—obtain susceptibility testing, as many strains remain susceptible and can be treated with the more convenient oral fluconazole regimen. 1

Do not continue therapy without addressing structural abnormalities (obstruction, retained catheters)—failure to correct these predisposing factors leads to treatment failure and recurrence. 1, 6