What antifungals are used to treat Candida in urine?

Antifungal Treatment for Candida in Urine

Fluconazole is the first-line antifungal treatment for symptomatic Candida urinary tract infections, at a dosage of 200 mg (3 mg/kg) daily for 2 weeks for susceptible species. 1

Treatment Algorithm Based on Clinical Presentation

Asymptomatic Candiduria

• No treatment needed unless patient belongs to high-risk group 1
• High-risk groups requiring treatment:
  • Neutropenic patients
  • Low birth weight infants
  • Patients undergoing urologic procedures

Symptomatic Candida Cystitis

1. First-line therapy: Fluconazole 200 mg daily for 2 weeks 1, 2

   • Highly effective due to water solubility and high urinary concentrations 1
   • Consider 200 mg loading dose followed by 100 mg daily for at least 4 days as an alternative regimen 3

2. For fluconazole-resistant species:

   • C. glabrata: Oral flucytosine 25 mg/kg 4 times daily for 7-10 days 1
   • C. krusei: Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
   • C. auris: Liposomal amphotericin B 3-5 mg/kg/day IV 4

3. Alternative therapy for resistant strains:

   • Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
   • Amphotericin B bladder irrigation (50 mg/L sterile water) for refractory cases with fluconazole-resistant species 1, 4

Candida Pyelonephritis

1. First-line therapy: Fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1

2. For fluconazole-resistant species:

   • Amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 25 mg/kg 4 times daily for 2 weeks 1
   • Flucytosine alone 25 mg/kg 4 times daily for 2 weeks 1

Fungus Balls

1. Surgical intervention is strongly recommended in non-neonates 1
2. Systemic therapy:
   • Fluconazole 200-400 mg daily 1
   • Amphotericin B deoxycholate 0.5-0.7 mg/kg daily with or without flucytosine 1
3. Local therapy: Amphotericin B irrigation at 50 mg/L sterile water if access to collecting system is available 1

Important Clinical Considerations

Elimination of Predisposing Factors

• Remove indwelling catheters 1, 5
• Discontinue unnecessary antibiotics 5
• Correct urinary tract obstruction 1
• These interventions alone may resolve candiduria in up to 50% of cases 6

Antifungal Agents to Avoid

• Newer azoles (voriconazole, posaconazole) - poor urinary concentrations 1, 6
• Echinocandins (caspofungin, micafungin, anidulafungin) - poor urinary concentrations 1, 7, 6
  • Exception: Some case reports show success with higher-dose micafungin (150 mg daily) in specific cases of resistant C. krusei 8

Duration of Treatment

• Continue treatment until symptoms resolve and urine cultures no longer yield Candida species 1, 4
• Standard duration is 2 weeks for most infections 1, 4

Monitoring

• Follow-up urine cultures to document clearance 4
• Monitor renal function when using amphotericin B formulations 4
• Assess for clinical improvement of symptoms 4

Pitfalls and Caveats

• Candiduria often represents colonization rather than infection, especially in catheterized patients 9
• Flucytosine monotherapy can lead to development of resistance; use with caution 1
• Amphotericin B bladder irrigation has high relapse rates and should be reserved for refractory cases 1
• Lipid formulations of amphotericin B do not achieve adequate urine concentrations for lower UTI treatment 1
• Echinocandins may be considered for renal parenchymal infections despite poor urinary concentrations, but clinical data is limited 1