What is the treatment for yeast cells in urine, a sign of a fungal urinary tract infection?

Treatment of Yeast Cells in Urine

Most patients with yeast cells in urine do not require antifungal treatment—only treat if symptomatic, neutropenic, very low-birth-weight infants (<1500g), severely immunocompromised with fever, or undergoing urologic procedures within several days. 1

Initial Clinical Decision: Who Needs Treatment?

The presence of yeast in urine represents colonization in the majority of cases and does not warrant therapy. 2, 1 However, specific high-risk populations require immediate treatment:

Mandatory treatment indications:

• Symptomatic urinary tract infection (dysuria, frequency, urgency, suprapubic pain) 1, 3
• Neutropenic patients (risk of disseminated candidiasis) 1
• Very low-birth-weight infants <1500g 1
• Patients scheduled for urologic procedures or manipulation within several days 1, 4
• Severely immunocompromised patients with fever and candiduria (concern for candidemia) 1

Do not treat asymptomatic candiduria in patients without these risk factors, as this leads to unnecessary antifungal exposure and potential resistance development. 1

Non-Pharmacologic Management First

Remove or replace indwelling urinary catheters immediately—this alone resolves candiduria in approximately 50% of cases without any antifungal therapy. 1, 4, 5 Catheter removal is the single most important intervention and should occur before or during antifungal treatment. 1

Address any urinary tract obstruction, as elimination of obstruction is strongly recommended for successful treatment. 4

First-Line Pharmacologic Treatment

Fluconazole is the drug of choice for all Candida urinary tract infections because it achieves high urinary concentrations in its active form and has proven efficacy. 2, 1, 6, 5

Treatment Regimens by Clinical Presentation:

For symptomatic cystitis (lower UTI):

• Oral fluconazole 200 mg (3 mg/kg) daily for 14 days 1, 4, 7
• This achieves 82% efficacy for fluconazole-susceptible organisms 7

For pyelonephritis (upper UTI):

• Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 14 days 1, 4, 7
• Use the higher dose (400 mg) for more severe upper tract infections 7

For patients undergoing urologic procedures:

• Fluconazole 400 mg (6 mg/kg) daily for several days before and after the procedure 1, 4

Alternative Regimens for Fluconazole-Resistant Organisms

When dealing with fluconazole-resistant species (particularly C. glabrata or C. krusei):

Amphotericin B deoxycholate:

• 0.3-0.6 mg/kg IV daily for 1-7 days 1, 4, 3
• Alternative dosing: 0.5-0.7 mg/kg daily with or without flucytosine 2

Oral flucytosine:

• 25 mg/kg four times daily for 7-10 days 1, 4
• Has good activity but carries toxicity concerns and resistance risk when used alone 2, 1

Amphotericin B bladder irrigation:

• 50 mg/L sterile water instilled into bladder 2, 1
• Reserve only for refractory fluconazole-resistant cystitis (C. glabrata or C. krusei) when systemic therapy has failed 1
• Resolves candiduria in 80-90% initially but has relapse rates exceeding 80-90% 1

Critical Pitfalls to Avoid

Never use echinocandins (caspofungin, micafungin, anidulafungin) or non-fluconazole azoles (voriconazole, posaconazole, itraconazole) for Candida urinary tract infections—these agents do not achieve therapeutic urinary concentrations and are ineffective for lower urinary tract infections. 1, 4, 5, 3

Never use lipid formulations of amphotericin B for urinary candidiasis, as they do not achieve adequate urine or renal tissue concentrations and treatment failures are well-documented. 2, 4

Always remove catheters before or during treatment—failure to address this predisposing factor leads to treatment failure and relapse regardless of antifungal choice. 1

Special Clinical Scenarios

If candiduria occurs with fever in a severely immunocompromised patient:

• Treat as candidemia with echinocandin therapy (NOT fluconazole), as this represents potential disseminated candidiasis 1

For fungus balls (bezoars) in the urinary collecting system:

• Surgical or endoscopic removal is mandatory in adults, combined with systemic antifungal therapy 1, 7
• Systemic treatment with amphotericin B deoxycholate (with or without flucytosine) or fluconazole 2

For Candida prostatitis or epididymo-orchitis:

• Fluconazole is the agent of choice 2
• Most patients require surgical drainage of abscesses in addition to antifungal therapy 2

Treatment Duration and Monitoring

Continue therapy until symptoms resolve and urine cultures no longer yield Candida species. 2, 7 Standard duration is 14 days for uncomplicated cases. 1, 4, 7

Imaging is indicated if treatment failure occurs despite appropriate therapy, or if there is suspicion of fungus balls, hydronephrosis, abscesses, or structural abnormalities. 7