What is the treatment for a urinary tract infection (UTI) caused by Candida glabrata?

Treatment of UTI Caused by Candida glabrata

For Candida glabrata urinary tract infections, amphotericin B deoxycholate 0.3-0.6 mg/kg daily for 1-7 days OR oral flucytosine 25 mg/kg 4 times daily for 7-10 days is strongly recommended as first-line therapy due to the inherent fluconazole resistance of this species. 1, 2

Treatment Algorithm for C. glabrata UTI

First-line options:

1. Amphotericin B deoxycholate: 0.3-0.6 mg/kg IV daily for 1-7 days

   • Advantages: Achieves high urinary concentrations
   • Disadvantages: IV administration required, potential nephrotoxicity

2. Flucytosine: 25 mg/kg orally 4 times daily for 7-10 days

   • Advantages: Oral administration, good urinary penetration
   • Disadvantages: Potential bone marrow toxicity, resistance development when used as monotherapy

For bladder-level infection (cystitis):

• Consider amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) for persistent infections 1
• This approach is particularly useful for fluconazole-resistant species like C. glabrata 1

For complicated infections or fungus balls:

• Surgical or endoscopic intervention is strongly recommended 1
• For nephrostomy tubes: Irrigation with amphotericin B deoxycholate (25-50 mg in 200-500 mL sterile water) 1

Important Clinical Considerations

Critical adjunctive measures:

• Remove indwelling catheters if present (strongly recommended) 1, 2
• Eliminate urinary tract obstruction if present (strongly recommended) 1
• Consider removal or replacement of nephrostomy tubes/stents if feasible 1

Treatment challenges with C. glabrata:

• C. glabrata is inherently less susceptible to fluconazole compared to C. albicans 1, 3
• Echinocandins (like caspofungin) have minimal urinary excretion and are generally ineffective for UTIs, despite their activity against C. glabrata in bloodstream infections 1, 4
• Lipid formulations of amphotericin B do not achieve adequate urine concentrations and should not be used 1

Monitoring recommendations:

• Follow-up urine cultures to confirm eradication 2
• Monitor renal function and electrolytes during amphotericin B therapy
• Monitor complete blood counts during flucytosine therapy due to potential bone marrow suppression

Special Situations

For patients with renal impairment:

• Adjust dosing based on creatinine clearance 2
• Consider flucytosine with careful monitoring if amphotericin B is contraindicated

For patients with obstructive pyonephrosis:

• Percutaneous drainage combined with local and systemic antifungal therapy is essential 4
• Intravenous antifungal therapy alone is often insufficient without drainage 4

Pitfalls to Avoid

1. Don't use fluconazole for C. glabrata UTIs - This species commonly demonstrates resistance 1, 3
2. Don't rely on echinocandins or newer azoles - These agents achieve inadequate urinary concentrations 1, 5
3. Don't overlook the importance of catheter removal - This intervention alone may resolve candiduria 2, 3
4. Don't treat asymptomatic candiduria unless the patient is in a high-risk group (neutropenic, very low birth weight infant, or undergoing urologic manipulation) 1, 3
5. Don't use lipid formulations of amphotericin B for UTIs as they don't achieve adequate urinary concentrations 1

By following this treatment algorithm and avoiding common pitfalls, clinicians can effectively manage UTIs caused by the challenging pathogen Candida glabrata.