What is the recommended treatment for a candidiasis (fungal infection) urinary tract infection (UTI)?

Treatment of Candida Urinary Tract Infection

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

Initial Assessment and Catheter Management

Remove or replace indwelling urinary catheters immediately if feasible—this alone resolves candiduria in approximately 50% of cases. 1, 2

• Asymptomatic candiduria does NOT require antifungal treatment in most patients, as it typically represents colonization rather than infection 1, 3
• Treatment of asymptomatic candiduria is indicated ONLY for: neutropenic patients, very low-birth-weight infants, or patients undergoing urologic procedures 1, 2, 3
• For patients with nephrostomy tubes or stents, consider removal or replacement if feasible 1

Treatment Algorithm for Symptomatic Cystitis (Lower UTI)

First-Line Therapy for Fluconazole-Susceptible Species

• Fluconazole 200 mg (3 mg/kg) orally daily for 2 weeks 1, 2
• Fluconazole is preferred because it achieves high urinary concentrations, has both oral and IV formulations, and demonstrated 82% efficacy in randomized controlled trials 4, 3

Alternative Therapy for Fluconazole-Resistant C. glabrata

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days 1
• OR Flucytosine 25 mg/kg orally 4 times daily for 7–10 days 1
• Amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) may be useful but has high recurrence rates 1, 4

Treatment for C. krusei

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days 1
• C. krusei exhibits intrinsic resistance to fluconazole 5

Treatment Algorithm for Pyelonephritis (Upper UTI)

• Fluconazole 200–400 mg (3–6 mg/kg) orally daily for 2 weeks 1
• Use the higher dose range (400 mg) for more severe upper tract infections 2
• For fluconazole-resistant C. glabrata: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days with or without flucytosine 25 mg/kg orally 4 times daily 1
• Elimination of urinary tract obstruction is mandatory 1

Critical Pitfalls to Avoid

• Do NOT use echinocandins (caspofungin, micafungin, anidulafungin) for lower urinary tract infections—they achieve minimal urinary concentrations and are generally ineffective for Candida UTI 6, 4, 7
• Do NOT use lipid formulations of amphotericin B—they do not achieve adequate urine concentrations 6
• Do NOT use other azoles besides fluconazole (itraconazole, voriconazole, posaconazole) for lower UTI—they have minimal urinary excretion 6, 7
• Colony counts cannot reliably differentiate colonization from infection, especially with catheters present 4

Special Considerations for Urologic Procedures

• For patients undergoing urologic procedures with candiduria: 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, 6, 4
• This prevents candidemia, which occurs at high rates when urinary tract instrumentation is performed in patients with candiduria 1

Duration of Therapy

• Standard duration is 2 weeks for uncomplicated cystitis and pyelonephritis 1, 2
• Continue treatment until symptoms resolve and urine cultures no longer yield Candida species 2, 6
• Recent evidence suggests shorter durations (median 7 days) may be equally effective, with one study showing no difference in clinical success between 7-day and 14-day courses (93.1% vs 93.3%, P=1.000) 8
• For neutropenic patients who remain persistently neutropenic, longer courses may be warranted pending resolution of neutropenia 1

Management of Fungus Balls and Complicated Infections

• Surgical intervention is mandatory for fungus balls, combined with antifungal therapy as outlined above 1
• Irrigation through nephrostomy tubes with amphotericin B deoxycholate 25–50 mg in 200–500 mL sterile water can be useful as adjunctive therapy 1
• Obtain imaging if treatment failure occurs despite appropriate therapy, or if fungus balls, hydronephrosis, abscesses, or structural abnormalities are suspected 2

Monitoring and Follow-Up

• Monitor for clinical improvement and obtain follow-up urine cultures to confirm clearance of infection 6
• For persistent infection despite appropriate therapy, imaging is indicated to rule out anatomical abnormalities or fungus balls 2, 6
• Candiduria does not commonly lead to candidemia, and treatment does not change mortality rates in most patients—candiduria is primarily a marker of underlying illness severity 1