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

Treatment of Fungal Urinary Tract Infections

For symptomatic fungal urinary tract infections, oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks is the first-line treatment for fluconazole-susceptible organisms. 1, 2

Diagnostic Considerations

• Differentiate between contamination, colonization, and true infection
• True infection typically presents with symptoms of UTI (dysuria, frequency, urgency)
• Asymptomatic candiduria generally does not require treatment except in:
  • Neutropenic patients
  • Patients undergoing urological procedures
  • Low birth weight infants

Treatment Algorithm Based on Candida Species

Fluconazole-Susceptible Candida (including C. albicans)

• First-line: Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1, 2
• For pyelonephritis: Increase dose to 200-400 mg (3-6 mg/kg) daily for 2 weeks 1
• Treatment should continue until symptoms resolve and urine cultures become negative 2

Fluconazole-Resistant C. glabrata

• First-line: Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
• Alternative options:
  • Amphotericin B deoxycholate with oral flucytosine (25 mg/kg 4 times daily) 1
  • Monotherapy with oral flucytosine (25 mg/kg 4 times daily for 2 weeks) 1
  • Amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) for refractory cystitis 1

C. krusei Infections

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

Critical Adjunctive Measures

• Remove indwelling bladder catheters if feasible (strong recommendation) 1, 2
• Eliminate urinary tract obstruction if present 1
• Consider removal or replacement of nephrostomy tubes or stents 1
• Discontinue unnecessary antibiotics 2

Special Considerations

Fungus Balls

• Require aggressive surgical debridement in addition to antifungal therapy 1
• Consider local irrigation with amphotericin B (50 mg/L sterile water) if direct access to collecting system is available 1
• Other methods include intermittent saline irrigation, debulking through percutaneous device, and irrigation with streptokinase 1

Prostatitis and Epididymo-orchitis

• Fluconazole is the agent of choice 1
• May require surgical drainage of abscesses or other surgical debridement 1

Important Pharmacological Considerations

• Fluconazole achieves high concentrations in urine, making it ideal for UTIs 1, 2
• Echinocandins and newer azoles (voriconazole, posaconazole) should NOT be used for uncomplicated fungal UTIs due to poor urinary concentrations 2
• Liposomal amphotericin B should NOT be used for lower UTIs due to inadequate urine concentrations 2
• Flucytosine should not be used as monotherapy due to risk of resistance development 2

Common Pitfalls to Avoid

• Treating asymptomatic candiduria unnecessarily 2
• Failing to remove indwelling catheters or address underlying conditions 2
• Using antifungals with poor urinary concentrations 2
• Not distinguishing between colonization and true infection 2
• Inadequate duration of therapy for symptomatic infections 2

Follow-up

• Obtain follow-up urine cultures to assess treatment effectiveness 2
• Monitor for symptom resolution 2
• Screen for potential complications or dissemination 2

By following this treatment algorithm and addressing underlying risk factors, most fungal UTIs can be effectively managed with appropriate antifungal therapy.