How should I treat a 55-year-old man with dysuria and urinary frequency, no fever or tachycardia, whose urine microscopy shows pyuria and yeast (Candida) cells?

Treatment of Candida Cystitis in a 55-Year-Old Man

This 55-year-old man with symptomatic Candida urinary tract infection (dysuria, frequency, pyuria, and yeast cells) requires fluconazole 200 mg orally once daily for 14 days as first-line therapy. 1

Immediate Management Steps

Remove Predisposing Factors First

• Remove any indwelling urinary catheter immediately if present, as catheter removal alone clears candiduria in approximately 50% of cases without requiring antifungal therapy. 1
• Discontinue any unnecessary broad-spectrum antibiotics that may be promoting fungal overgrowth. 2
• Evaluate for urinary tract obstruction, diabetes control, and other structural abnormalities that predispose to infection. 2

Confirm This is True Infection, Not Colonization

• This patient clearly has symptomatic infection requiring treatment because he presents with dysuria and urinary frequency along with pyuria and yeast cells. 1
• The presence of symptoms (burning urination, frequency) combined with pyuria distinguishes this from asymptomatic colonization. 2
• Unlike asymptomatic candiduria—which almost never requires treatment—symptomatic cystitis mandates antifungal therapy. 1

First-Line Antifungal Therapy

Fluconazole Regimen

• Fluconazole 200 mg (approximately 3 mg/kg) orally once daily for 14 days is the evidence-based first-line treatment for symptomatic Candida cystitis. 1
• This recommendation is based on the only randomized, double-blind, placebo-controlled trial demonstrating efficacy in eradicating candiduria. 2
• Fluconazole achieves exceptionally high urinary concentrations of active drug, ensuring effective pathogen eradication. 1
• The oral formulation provides excellent bioavailability, making intravenous administration unnecessary for uncomplicated cystitis. 2

Why Fluconazole is Preferred

• Fluconazole is excreted into urine in its active form and easily achieves concentrations exceeding the minimum inhibitory concentration (MIC) for most Candida species, particularly Candida albicans (the most common cause). 2
• Other azole antifungals (voriconazole, posaconazole) and echinocandins achieve minimal urinary concentrations and are ineffective for urinary tract infections. 2

Species-Specific Considerations

Assume Fluconazole-Susceptible Species Initially

• Candida albicans accounts for the majority of Candida urinary infections and is reliably susceptible to fluconazole. 2
• Begin empiric fluconazole therapy while awaiting species identification and susceptibility testing. 1

If Fluconazole-Resistant Species Identified

• For Candida glabrata (often fluconazole-resistant): Switch to 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
• For Candida krusei (intrinsically fluconazole-resistant): Use amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days. 1
• Amphotericin B deoxycholate achieves adequate urinary concentrations even at low doses, but requires intravenous administration and carries nephrotoxicity risk. 2

Critical Pitfalls to Avoid

Do Not Use Inadequate Agents

• Never use echinocandins (caspofungin, micafungin, anidulafungin) for urinary tract infections because they achieve negligible urine concentrations despite adequate tissue levels. 2
• Lipid formulations of amphotericin B do not achieve adequate urinary concentrations and should not be used for Candida UTI. 2

Assess for Upper Tract Involvement

• Evaluate for flank pain, fever, or systemic symptoms suggesting pyelonephritis rather than isolated cystitis. 1
• If pyelonephritis is suspected, increase fluconazole to 200–400 mg (3–6 mg/kg) daily for 14 days, using the higher 400 mg dose when upper tract involvement is confirmed. 1

Screen for Complications

• Obtain renal imaging (ultrasound or CT) if symptoms persist despite appropriate therapy, to exclude urinary obstruction, fungal balls, abscess formation, or emphysematous pyelonephritis. 2
• Fungal balls (aggregations of mycelia and yeasts) in bladder or kidney cause obstruction and preclude successful treatment with antifungals alone—these require surgical intervention. 2

Follow-Up and Treatment Failure

Expected Response

• Clinical symptoms (dysuria, frequency) should improve within 3–5 days of initiating fluconazole. 1
• Repeat urinalysis after completing the 14-day course to document mycological clearance. 1

If Treatment Fails

• Verify medication adherence and confirm the patient completed the full 14-day course. 1
• Obtain urine culture with species identification and antifungal susceptibility testing to identify fluconazole-resistant organisms. 1
• Re-evaluate for unrecognized urinary tract obstruction, retained foreign bodies (stents, nephrostomy tubes), or prostatic involvement. 2
• Consider imaging to exclude fungal balls or structural abnormalities requiring surgical management. 2