What is the treatment for a patient with a urinary analysis (UA) positive for Candida glabrata, indicating a fungal urinary tract infection (UTI)?

Treatment of Candida glabrata Urinary Tract Infection

First-Line Treatment Recommendation

For symptomatic Candida glabrata cystitis, treat with oral fluconazole 200 mg daily for 2 weeks, but be prepared to switch to amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days if the isolate proves fluconazole-resistant, which is common with C. glabrata. 1, 2

Critical Initial Assessment

Before initiating treatment, determine whether this represents true infection versus colonization:

• Treat if symptomatic (dysuria, frequency, urgency, suprapubic pain, fever, flank pain) or if the patient has urinary retention/obstruction 2
• Treat if high-risk asymptomatic patient: neutropenic, very low-birth-weight infant, or undergoing urologic procedures 1, 3
• Do not treat asymptomatic candiduria in other patients, as this typically represents colonization 1, 4
• Remove or replace urinary catheter if present, as this alone resolves candiduria in approximately 40-50% of cases 1, 2

Treatment Algorithm by Clinical Scenario

Uncomplicated Cystitis (Lower UTI)

Start with fluconazole 200 mg orally daily for 2 weeks as first-line therapy 1, 2

However, C. glabrata has significant fluconazole resistance rates (~20% of urine isolates), so:

• If fluconazole-resistant C. glabrata is confirmed, switch to amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days 1, 2
• Alternative option: oral flucytosine 25 mg/kg four times daily for 7-10 days, used alone or combined with amphotericin B 2
• Bladder irrigation with amphotericin B deoxycholate (50 mg/L sterile water) can be considered for refractory azole-resistant cystitis, though relapse rates are high 1

Pyelonephritis (Upper UTI)

C. glabrata accounts for ~20% of adult urine isolates and frequently requires amphotericin B deoxycholate rather than fluconazole for pyelonephritis 1

• Amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily is the preferred agent for C. glabrata pyelonephritis 1
• Do not use lipid formulations of amphotericin B, as they achieve inadequate urine concentrations and have documented treatment failures 1
• Continue treatment for at least 2 weeks after symptom resolution 1, 2

Obstructive Uropathy or Urinary Retention

Urgently address the obstruction alongside antifungal therapy, as obstruction precludes successful treatment with antifungals alone 2, 5

• Fluconazole or amphotericin B (depending on susceptibility) plus urgent relief of obstruction 2
• If nephrostomy tube is present, consider irrigation with amphotericin B deoxycholate 25-50 mg in 200-500 mL sterile water 1

Fungus Balls

Surgical or endoscopic removal is mandatory in addition to systemic antifungal therapy 1

• Systemic amphotericin B deoxycholate (with or without flucytosine) or fluconazole (if susceptible) 1
• Local irrigation through nephrostomy tube with amphotericin B deoxycholate 25-50 mg in 200-500 mL sterile water 1

Critical Pitfalls to Avoid

Do not use echinocandins (caspofungin, micafungin, anidulafungin) for lower urinary tract C. glabrata infections, as they achieve minimal urinary concentrations and are generally ineffective 1, 2

• While isolated case reports describe success with echinocandins for C. glabrata UTI 6, 7, and they may work for hematogenous renal parenchymal infection where tissue concentrations are adequate 1, 7, the IDSA guidelines explicitly state echinocandins have minimal urinary excretion and are generally ineffective for UTI 1
• Both successes and failures with echinocandins have been reported, making them unreliable 1, 5

Do not use lipid formulations of amphotericin B for UTI, as they do not achieve adequate urine concentrations 1

Do not use other azoles (voriconazole, posaconazole, isavuconazole) or other antifungals besides fluconazole, as they achieve minimal urinary concentrations 1, 2

Monitoring and Follow-Up

• Obtain species identification and susceptibility testing to guide therapy, especially for C. glabrata which has variable fluconazole susceptibility 1, 3
• Assess for disseminated candidiasis if the patient has additional risk factors such as neutropenia or severe immunocompromise 2
• Obtain imaging (ultrasound or CT) if treatment fails despite appropriate therapy to identify fungus balls, hydronephrosis, abscesses, or structural abnormalities 2, 8
• Continue treatment until symptoms resolve and repeat urine cultures no longer yield Candida 2, 8