What is the recommended treatment for Candida (fungal infection) urinary tract infections (UTIs)?

Treatment of Candida Urinary Tract Infections

For symptomatic Candida UTI with fluconazole-susceptible organisms, oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks is the recommended treatment, combined with removal of indwelling urinary catheters whenever feasible. 1

Initial Assessment: Determine if Treatment is Needed

Most candiduria does not require antifungal therapy. The critical first step is distinguishing colonization from true infection and identifying high-risk patients. 1

Patients Who DO NOT Need Treatment:

• Asymptomatic candiduria in immunocompetent patients with normal urinary tracts 1
• Simple catheter-associated candiduria without symptoms 1
• Elimination of predisposing factors (especially catheter removal) often resolves candiduria without antifungals 1

Patients Who REQUIRE Treatment:

• Symptomatic cystitis or pyelonephritis (dysuria, frequency, urgency, flank pain, fever) 1
• High-risk patients even if asymptomatic: neutropenic patients, very low-birth-weight infants (<1500 g) 1
• Patients undergoing urologic procedures (prophylactic treatment required) 1
• Suspected disseminated candidiasis (treat as candidemia) 1

Treatment Algorithm for Symptomatic Candida Cystitis

For Fluconazole-Susceptible Species (C. albicans, most C. parapsilosis, C. tropicalis):

• Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1, 2
• This is a strong recommendation with moderate-quality evidence 1
• Fluconazole achieves high urinary concentrations and has proven efficacy in randomized controlled trials 2, 3, 4

For Fluconazole-Resistant C. glabrata:

• Amphotericin B deoxycholate 0.3–0.6 mg/kg daily for 1–7 days 1, 2
• OR oral flucytosine 25 mg/kg four times daily for 7–10 days 1
• Bladder irrigation with amphotericin B (50 mg/L sterile water daily for 5 days) may be considered but has high recurrence rates 1, 2

For C. krusei:

• Amphotericin B deoxycholate 0.3–0.6 mg/kg daily for 1–7 days 1, 2
• C. krusei is intrinsically resistant to fluconazole 1

Treatment Algorithm for Candida Pyelonephritis

For Fluconazole-Susceptible Organisms:

• Oral fluconazole 200–400 mg (3–6 mg/kg) daily for 2 weeks 1
• Higher doses (400 mg) are preferred for upper tract involvement 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
• OR flucytosine monotherapy 25 mg/kg four times daily for 2 weeks (weaker recommendation) 1

For C. krusei:

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

Essential Non-Pharmacologic Interventions

These interventions are as important as antifungal therapy:

• Remove indwelling bladder catheters whenever feasible (strong recommendation) 1, 2
• Eliminate urinary tract obstruction (strong recommendation) 1
• Consider removal or replacement of nephrostomy tubes or stents if present 1, 2
• Catheter removal alone resolves candiduria in approximately 50% of cases 5

Prophylaxis for Urologic Procedures

Patients with candiduria undergoing urologic manipulation require prophylaxis:

• Oral fluconazole 400 mg (6 mg/kg) daily 1, 2
• OR amphotericin B deoxycholate 0.3–0.6 mg/kg daily 1
• Administer for several days before and after the procedure 1

Critical Pitfalls to Avoid

Do NOT Use These Agents for Lower UTI:

• Echinocandins (caspofungin, micafungin, anidulafungin): Minimal urinary excretion makes them ineffective for cystitis, though they may work for renal parenchymal infections 2, 6, 7
• Lipid formulations of amphotericin B: Do not achieve adequate urine concentrations 2, 6
• Voriconazole, itraconazole, posaconazole: Poor urinary concentrations 2, 6

Other Important Caveats:

• Colony counts cannot reliably differentiate colonization from infection when catheters are present 2
• Bladder irrigation with amphotericin B has 80-90% initial success but high recurrence rates and is generally discouraged except for resistant species 2, 7
• Flucytosine monotherapy risks resistance development and has toxicity concerns (bone marrow suppression, hepatotoxicity) requiring monitoring 2, 7
• Always confirm candiduria with a second urine specimen to eliminate contamination before initiating treatment 5

Special Populations

Neutropenic Patients and Very Low-Birth-Weight Infants:

• Treat as candidemia with systemic antifungal therapy (not just as UTI) 1
• These patients are at high risk for dissemination 1

Fungus Balls (Renal or Bladder):

• Surgical intervention is strongly recommended in adults 1
• Irrigation through nephrostomy tubes with amphotericin B (25-50 mg in 200-500 mL sterile water) if tubes are present 1
• Systemic antifungal therapy as outlined above for pyelonephritis 1