What is the treatment for Candida urinary tract infections (UTI)?

Treatment of Candida Urinary Tract Infections

For symptomatic Candida UTI, fluconazole 200 mg (3 mg/kg) orally daily for 2 weeks is the first-line treatment, while asymptomatic candiduria typically requires no treatment unless the patient is neutropenic, a very low-birth-weight infant, or undergoing urologic procedures. 1, 2

Initial Assessment: Distinguish Infection from Colonization

• Most candiduria represents colonization or contamination, not true infection 3, 4
• Remove or replace urinary catheters immediately if feasible—this alone resolves candiduria in approximately 50% of cases 5, 6
• Eliminate other predisposing factors (broad-spectrum antibiotics, urinary obstruction) as this often results in spontaneous resolution 1, 7
• Do NOT treat asymptomatic candiduria in most patients 1, 2

High-Risk Patients Requiring Treatment Despite Asymptomatic Candiduria:

• Neutropenic patients 1, 2
• Very low-birth-weight infants 1, 8
• Patients undergoing urologic procedures (treat prophylactically with fluconazole 200-400 mg daily or amphotericin B deoxycholate 0.3-0.6 mg/kg daily for several days before and after the procedure) 1, 2

Treatment Algorithm for Symptomatic Candida UTI

Candida Cystitis (Lower UTI):

• Fluconazole 200 mg (3 mg/kg) orally daily for 2 weeks is the drug of choice for fluconazole-susceptible species 1, 5, 9
• Fluconazole achieves high urinary concentrations in its active form and has demonstrated 82% efficacy 8, 3

Candida Pyelonephritis (Upper UTI):

• Fluconazole 200-400 mg (3-6 mg/kg) orally daily for 2 weeks for fluconazole-susceptible organisms 1, 5
• Use the higher dose (400 mg) for more severe upper tract infections 8

Alternative Regimens for Fluconazole-Resistant Organisms (especially C. glabrata and C. krusei):

• Amphotericin B deoxycholate 0.3-0.6 mg/kg IV daily for 1-7 days 1, 2
• Flucytosine 25 mg/kg orally 4 times daily for 7-10 days (use with caution due to toxicity and resistance development when used alone) 1
• For pyelonephritis with resistant organisms: Amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 25 mg/kg 4 times daily for 2 weeks 1

Critical Pharmacologic Considerations

Why fluconazole is preferred:

• Achieves high urinary concentrations in active form 1, 7
• Available in both oral and IV formulations 3, 6
• Excellent safety profile 3

Agents to AVOID for Candida UTI:

• Do NOT use echinocandins (caspofungin, micafungin, anidulafungin) for lower UTI—they achieve minimal urinary concentrations and are generally ineffective 5, 3
• Do NOT use other azoles besides fluconazole (itraconazole, voriconazole, posaconazole)—they have minimal excretion of active drug into urine 1, 6
• Do NOT use lipid formulations of amphotericin B—they do not achieve adequate urine or renal tissue concentrations and have documented treatment failures 1, 5

Special Clinical Scenarios

Fungus Balls:

• Require aggressive surgical debridement in addition to systemic antifungal therapy 1, 8
• If percutaneous access available, consider irrigation with amphotericin B 50 mg/L sterile water as adjunct to systemic therapy 1

Suspected Disseminated Candidiasis with Candiduria:

• Treat as candidemia with systemic antifungal therapy, not as isolated UTI 1

Amphotericin B Bladder Irrigation:

• Generally NOT recommended due to high relapse rates (though resolves candiduria in 80-90% initially) 1, 2
• May be considered only for refractory cystitis due to fluconazole-resistant C. glabrata or C. krusei 1

Treatment Duration and Monitoring

• Continue treatment until symptoms resolve AND urine cultures no longer yield Candida species 1, 5
• Standard duration is 2 weeks for uncomplicated cystitis and pyelonephritis 1, 8
• Obtain follow-up urine cultures to confirm clearance 5
• If treatment fails despite appropriate therapy, obtain imaging to rule out anatomical abnormalities, fungus balls, hydronephrosis, or abscesses 5, 8

Common Pitfalls to Avoid

• Colony count cannot reliably differentiate colonization from infection, especially with catheters in place 2
• Do not treat asymptomatic candiduria reflexively—elimination of predisposing factors alone is often sufficient 1, 7
• Do not use fluconazole if the patient was already on fluconazole prophylaxis, as resistance is likely 1
• Address urinary tract obstruction—it is critical to treatment success and must be corrected 5