For a patient with significant yeast growth in urine culture and urinary symptoms, should antifungal therapy be initiated and if so, what antifungal agent should be started?

Treatment of Candida Urinary Tract Infection with Urinary Retention

For a patient with 30,000 CFU yeast in urine culture, urinary symptoms, and urinary retention, you should initiate antifungal therapy with oral fluconazole 200 mg daily for 2 weeks, and urgently address the urinary retention. 1

When to Treat Candiduria

Antifungal therapy is indicated in this case because the patient has both urinary symptoms AND urinary retention (obstruction). 1

• The presence of urinary symptoms distinguishes this from asymptomatic colonization, which typically does not require treatment 1, 2
• Urinary retention represents obstruction, which is a strong indication for treatment regardless of symptom severity 1
• The colony count of 30,000 CFU, while lower than the traditional 10^5 threshold, is clinically significant in the context of symptoms and obstruction 1, 3

First-Line Antifungal Selection

Fluconazole is the drug of choice for symptomatic Candida cystitis. 1

Dosing for Symptomatic Cystitis

• Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1
• If pyelonephritis is suspected (flank pain, fever, systemic signs), increase to fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1

Why Fluconazole is Preferred

• Achieves high concentrations in urine in its active form 1, 4
• Available as oral formulation, making it convenient and well-tolerated 1
• Proven efficacy in the only randomized controlled trial for candiduria 1
• Effective against most Candida species, particularly C. albicans 1

Critical Management of Urinary Retention

Elimination of urinary tract obstruction is strongly recommended and takes priority alongside antifungal therapy. 1

• Urinary retention must be addressed urgently, as obstruction precludes successful antifungal treatment alone 1
• If an indwelling catheter is present, remove it if feasible, as catheter removal alone resolves candiduria in approximately 40-50% of cases 1, 2, 5
• If nephrostomy tubes or stents are present, consider removal or replacement 1
• Imaging with ultrasound or CT may be needed to assess for fungus balls, hydronephrosis, or structural abnormalities 1

Alternative Agents for Resistant Species

If the Candida species is identified as fluconazole-resistant (C. glabrata or C. krusei), alternative therapy is required. 1

For Fluconazole-Resistant C. glabrata

• Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
• Oral flucytosine 25 mg/kg four times daily for 7-10 days (can be used alone or with amphotericin B) 1

For C. krusei

• Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1

Critical Pitfalls to Avoid

Do not use echinocandins or other azoles (besides fluconazole) for lower urinary tract Candida infections. 1, 5

• Echinocandins (caspofungin, micafungin, anidulafungin) achieve minimal urinary concentrations and are ineffective for cystitis 1
• Other azoles (voriconazole, itraconazole, posaconazole) have minimal excretion of active drug into urine 1
• Lipid formulations of amphotericin B do not achieve adequate urine concentrations and should not be used 1

Do not delay addressing the urinary retention while waiting for species identification. 1

• Obstruction must be relieved for antifungal therapy to be effective 1
• If fungus balls are present, surgical intervention may be required in addition to antifungals 1

Monitoring and Follow-Up

Assess for disseminated candidiasis if the patient has additional risk factors. 1

• If the patient is neutropenic, severely immunocompromised, or has persistent fever, treat as disseminated candidiasis rather than isolated UTI 1
• Consider blood cultures and imaging if candidemia is suspected 1

Recent evidence suggests shorter treatment durations may be effective, though guidelines still recommend 14 days. 6

• A 2025 study found no difference in clinical success between 7-day and 14-day fluconazole courses for symptomatic Candida UTI 6
• However, current IDSA guidelines continue to recommend 2 weeks of therapy 1