Treatment of Yeast in Urine Culture
Most patients with yeast in urine culture do NOT require antifungal treatment unless they are neutropenic, very low-birth-weight infants, or undergoing urologic procedures. 1
Initial Management: Remove Predisposing Factors First
- Catheter removal is the most critical first step and is strongly recommended whenever feasible 1
- Eliminating predisposing factors (indwelling catheters, unnecessary antibiotics) resolves candiduria in approximately 40-50% of asymptomatic patients without any antifungal therapy 1, 2
- Observation alone is appropriate for asymptomatic patients without risk factors 1
Who Requires Treatment?
High-risk patients requiring antifungal therapy include: 1
- Neutropenic patients (treat as candidemia)
- Very low-birth-weight infants (<1500g) (treat as candidemia)
- Patients with symptomatic cystitis or pyelonephritis
- Patients undergoing urologic manipulation/procedures
Treatment by Clinical Scenario
Asymptomatic Candiduria in Patients Undergoing Urologic Procedures
- Oral fluconazole 400 mg (6 mg/kg) daily OR amphotericin B deoxycholate 0.3-0.6 mg/kg daily for several days before and after the procedure 1
Symptomatic Cystitis (Bladder Infection)
For fluconazole-susceptible organisms (most C. albicans):
- Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1
- Remove indwelling bladder catheter if present 1
For fluconazole-resistant C. glabrata:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
- OR oral flucytosine 25 mg/kg four times daily for 7-10 days 1
- Amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) may be useful as adjunctive therapy but has high relapse rates when used alone 1
For C. krusei:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
Pyelonephritis (Kidney Infection)
For fluconazole-susceptible organisms:
- Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1
- Eliminate urinary tract obstruction; remove or replace nephrostomy tubes/stents if feasible 1
For fluconazole-resistant C. glabrata:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days with or without oral flucytosine 25 mg/kg four times daily 1
- Flucytosine monotherapy (25 mg/kg four times daily for 2 weeks) is a weaker alternative 1
For C. krusei:
- Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
Fungus Balls (Bezoars)
- Surgical intervention is strongly recommended 1
- Systemic antifungal therapy: Fluconazole 200-400 mg (3-6 mg/kg) daily OR amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 25 mg/kg four times daily 1
- Continue treatment until symptoms resolve and urine cultures are negative 1
Key Rationale and Evidence Quality
The 2016 IDSA guidelines provide the highest quality evidence for candiduria management 1. Fluconazole is the drug of choice because it achieves high urinary concentrations in its active form and was proven effective in the only randomized, double-blind, placebo-controlled trial for candiduria 1. The FDA label confirms fluconazole's indication for Candida urinary tract infections 3.
Critical Pitfalls to Avoid
- Do not treat asymptomatic candiduria in immunocompetent patients - this leads to unnecessary antifungal exposure and promotes resistance 1
- Never rely on pyuria or colony counts to differentiate colonization from infection in catheterized patients - these tests are not helpful 1
- Echinocandins and newer azoles (voriconazole, posaconazole) should NOT be used for urinary tract infections - they fail to achieve adequate urine concentrations 2
- Bladder irrigation alone has unacceptably high relapse rates and should only be considered as adjunctive therapy for resistant organisms 1
- Failure to remove catheters significantly reduces treatment success regardless of antifungal choice 1