What is the appropriate treatment for candiduria with a colony count over 100,000 CFU (colony-forming units) per milliliter of urine?

Treatment for Candiduria with Colony Count Over 100,000 CFU/mL

For candiduria with colony counts over 100,000 CFU/mL, oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks is the recommended treatment for symptomatic infections caused by fluconazole-susceptible Candida species. 1

Assessment and Initial Management

Before initiating antifungal therapy, determine if treatment is actually needed:

• Asymptomatic candiduria: Treatment is generally NOT recommended unless the patient belongs to a high-risk group 1
• High-risk groups requiring treatment despite being asymptomatic:
  • Neutropenic patients
  • Very low-birth-weight infants (<1500g)
  • Patients undergoing urologic procedures 1

Treatment Algorithm

Step 1: Remove predisposing factors

• Remove indwelling bladder catheters if feasible (strongly recommended) 1
  • This alone resolves candiduria in nearly 50% of cases 2
• Eliminate urinary tract obstruction if present 1
• Consider removal/replacement of nephrostomy tubes or stents if present 1

Step 2: Select appropriate antifungal therapy based on Candida species

For Candida albicans and other fluconazole-susceptible species:

• First-line: Oral fluconazole 200 mg (3 mg/kg) daily for 2 weeks 1
  • Some guidelines suggest a loading dose of 400 mg on day 1 followed by 200 mg daily 3

For fluconazole-resistant C. glabrata:

• Option 1: Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days 1
• Option 2: Oral flucytosine 25 mg/kg 4 times daily for 7-10 days 1
• Option 3: Combination of amphotericin B with flucytosine 1

For C. krusei:

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

Step 3: For refractory cases with fluconazole-resistant species

• Consider amphotericin B deoxycholate bladder irrigation (50 mg/L sterile water daily for 5 days) 1

Special Clinical Scenarios

Pyelonephritis

• For fluconazole-susceptible organisms: Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks 1
• For fluconazole-resistant species: Amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days with or without flucytosine 1

Fungus Balls

• Surgical intervention is strongly recommended 1
• Antifungal therapy as noted above for cystitis or pyelonephritis 1
• If access to renal collecting system is available, irrigation with amphotericin B deoxycholate (25-50 mg in 200-500 mL sterile water) 1

Patients Undergoing Urologic Procedures

• Oral 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

Important Clinical Considerations

• Newer azole agents and echinocandins are not recommended for urinary tract infections as they fail to achieve adequate urine concentrations 2
• Fluconazole is preferred because it is highly water-soluble, primarily excreted in urine in its active form, and easily achieves urine levels exceeding the MIC for most Candida strains 1
• Diagnostic tests on urine often cannot differentiate colonization from infection, especially when a catheter is present 1
• Colony count alone cannot define infection when a catheter is present 1

Common Pitfalls to Avoid

1. Treating asymptomatic candiduria in patients who are not at high risk for dissemination
2. Failing to remove or replace indwelling catheters when possible
3. Using echinocandins or newer azoles for urinary tract infections
4. Not considering species-specific treatment for non-albicans Candida species
5. Overlooking the possibility of fungus balls or obstructive uropathy, which require surgical intervention

The treatment of candiduria should focus on symptomatic patients or high-risk asymptomatic patients, with fluconazole being the cornerstone of therapy for susceptible species and appropriate alternatives for resistant strains.