What is the recommended treatment for Candida glabrata urinary tract infections (UTI)?

Treatment of Candida glabrata UTI

For Candida glabrata UTI, use amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days or oral flucytosine 25 mg/kg four times daily for 7–10 days, and always remove indwelling urinary catheters immediately when present. 1

Critical First Step: Assess Fluconazole Susceptibility

• Determining fluconazole susceptibility is mandatory before initiating therapy, as C. glabrata exhibits variable and often high resistance patterns to azoles 1
• C. glabrata represents approximately 20% of urinary isolates in adults and is frequently resistant to fluconazole, making it unsuitable as first-line therapy 2
• Unlike C. albicans or C. tropicalis infections where fluconazole is preferred, C. glabrata requires alternative agents due to intrinsic or acquired azole resistance 2

Treatment Algorithm Based on Infection Site

For Cystitis (Lower UTI)

• Primary options: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days OR oral flucytosine 25 mg/kg four times daily for 7–10 days 1
• Remove indwelling bladder catheter immediately if present (strong recommendation) 1
• Catheter removal alone resolves candiduria in approximately 50% of cases 3

For Pyelonephritis (Upper UTI)

• Primary therapy: 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
• Eliminate any urinary tract obstruction (strong recommendation) 1
• Amphotericin B achieves urinary concentrations exceeding MICs for most Candida isolates including C. glabrata, and is effective even at low doses for UTI 1

Essential Management Principles

Catheter Removal

• Removing indwelling urinary catheters is essential and strongly recommended, as catheters perpetuate infection and colonization 1
• This is the single most important non-pharmacological intervention 2

Special Clinical Circumstances

Obstructive uropathy or fungus balls:

• Surgical or endoscopic intervention is mandatory (strong recommendation) 1
• Antifungal therapy alone will likely fail without drainage 1
• Case reports demonstrate that even newer agents like caspofungin fail in obstructive pyonephrosis without drainage and local amphotericin B instillation 4

Asymptomatic candiduria:

• Treatment is required only in high-risk patients: neutropenic patients, very low-birth-weight infants (<1500g), and patients undergoing urologic procedures 1, 2
• Neutropenic patients should be treated as if they have candidemia 2

Why Not Echinocandins?

• Current guidelines do not recommend echinocandins (caspofungin, micafungin) as first-line treatment due to low urinary concentrations, limited clinical data, and documented therapeutic failures 2
• While isolated case reports describe successful treatment of C. glabrata UTI with micafungin 5, 6, these represent anecdotal evidence
• Echinocandins may be considered only in specific circumstances, such as severe renal insufficiency or when amphotericin B and flucytosine cannot be used 2
• A case report specifically documented failure of caspofungin in obstructive pyonephrosis due to C. glabrata, requiring drainage and amphotericin B for cure 4

Flucytosine Considerations

• Flucytosine has good activity against C. glabrata but its use as monotherapy is limited due to toxicity and rapid development of resistance 2
• It can be combined with amphotericin B for pyelonephritis 1
• Dose is 25 mg/kg four times daily for 7–10 days 1

Common Pitfalls to Avoid

• Do not use fluconazole empirically for suspected C. glabrata UTI without susceptibility testing 1, 2
• Do not rely on echinocandins as first-line therapy despite their favorable safety profile 2, 4
• Do not treat with antifungals alone if obstruction or fungus balls are present—drainage is mandatory 1
• Do not forget to remove catheters—this is as important as antifungal selection 1, 2

Monitoring and Duration

• Continue therapy until symptoms resolve and urine cultures no longer yield Candida species 3
• Standard duration is 7–10 days for cystitis and similar for pyelonephritis, though amphotericin B may be given for as few as 1–7 days depending on clinical response 1
• If treatment failure occurs despite appropriate therapy, obtain imaging to evaluate for fungus balls, hydronephrosis, abscesses, or structural abnormalities 3