Management of Candida Urinary Tract Infection in Adults
Initial Critical Decision: Treat or Observe?
Most patients with candiduria should NOT receive antifungal therapy because candiduria almost always represents benign colonization rather than true infection, and treatment does not reduce mortality or improve outcomes. 1, 2
High-Risk Patients Who MUST Be Treated Despite Lack of Symptoms
Treatment is mandatory for the following groups, even when asymptomatic: 1, 2
- Neutropenic patients with persistent unexplained fever and candiduria (risk of disseminated candidiasis) 1, 2
- Very low-birth-weight neonates (<1500 g) due to high propensity for invasive disease 1, 2
- Patients undergoing urologic procedures or instrumentation within several days (risk of procedure-related candidemia) 1, 2
- Patients with urinary tract obstruction that cannot be promptly relieved 1
Symptomatic Patients Requiring Treatment
Treat all patients with: 2
- Dysuria, frequency, urgency
- Flank pain suggesting pyelonephritis
- Fever >38.3°C with urinary symptoms
- Signs of prostatitis or epididymo-orchitis in males
First-Line Non-Pharmacologic Management (ESSENTIAL)
Immediate removal of any indwelling urinary catheter is the single most important intervention and resolves candiduria in approximately 50% of cases without antifungal therapy. 1, 2
Additional critical steps: 1, 2
- Discontinue unnecessary broad-spectrum antibiotics
- Eliminate urinary tract obstruction
- Remove or replace nephrostomy tubes/ureteral stents if present
Common pitfall: Continuing catheterization is the most frequent cause of treatment failure and relapse. 2
Antifungal Treatment Regimens
For Symptomatic Candida Cystitis (Lower UTI)
Fluconazole 200 mg (3 mg/kg) orally once daily for 14 days is the preferred first-line therapy for fluconazole-susceptible Candida species. 1, 2, 3
- This recommendation is based on the only randomized, double-blind, placebo-controlled trial demonstrating efficacy 2
- Fluconazole achieves high urinary concentrations of active drug, ensuring effective pathogen eradication 1, 2
For Symptomatic Candida Pyelonephritis (Upper UTI)
Fluconazole 200–400 mg (3–6 mg/kg) orally once daily for 14 days is recommended; use the higher 400-mg dose when upper-tract involvement is confirmed. 1, 2
Suspect pyelonephritis when: 2
- Flank pain develops
- Fever >38.3°C
- Systemic manifestations appear
If symptoms persist beyond 48–72 hours, obtain renal/bladder imaging (ultrasound or CT) to exclude obstruction, fungal balls, or perinephric abscesses. 2
Management of Fluconazole-Resistant Species
Candida glabrata (Often Fluconazole-Resistant)
For cystitis: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days OR oral flucytosine 25 mg/kg four times daily for 7–10 days 1, 4
For pyelonephritis: Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days, with or without oral flucytosine 25 mg/kg four times daily 1, 4
- Amphotericin B achieves urinary concentrations exceeding MICs for most Candida isolates, including C. glabrata 4
- Flucytosine monotherapy (25 mg/kg four times daily for 7–10 days) may be considered when amphotericin B is unsuitable, but this is a weaker recommendation 1
Candida krusei (Intrinsically Fluconazole-Resistant)
Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the treatment of choice. 1, 3
Refractory Fluconazole-Resistant Cystitis
Amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) may be employed for refractory C. glabrata or C. krusei cystitis, but relapse rates exceed 80–90%. 1, 3
Important caveat: Bladder irrigation should be reserved only for refractory cases when systemic therapy has failed, as relapse is nearly universal. 3
Special Clinical Scenarios
Patients Undergoing Urologic Procedures
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, 2
Fungus Balls (Bezoars) or Obstructive Uropathy
Surgical or endoscopic removal is mandatory in addition to systemic antifungal therapy; antifungal therapy alone will fail without drainage. 1, 4, 3
For patients with nephrostomy tubes: irrigate with amphotericin B deoxycholate 25–50 mg diluted in 200–500 mL sterile water as adjunctive therapy. 1
Neutropenic Patients or Very Low-Birth-Weight Neonates
Treat as candidemia (not just UTI) to prevent disseminated disease: 1
- Echinocandin (caspofungin 70-mg loading dose then 50 mg daily, anidulafungin 200-mg loading dose then 100 mg daily, or micafungin 100 mg daily) OR
- Lipid formulation amphotericin B 3–5 mg/kg daily
- Continue for 2 weeks after documented clearance from bloodstream
Severely Immunocompromised Patients with Fever and Candiduria
If disseminated candidiasis is suspected, treat as candidemia with echinocandin therapy (NOT fluconazole as first-line). 3
Critical Pitfalls to Avoid
Do NOT treat asymptomatic candiduria in the following groups: 1, 2
- Otherwise healthy individuals
- Diabetic patients without other high-risk features
- Elderly patients without other indications
Do NOT use these agents for Candida UTI: 2, 3
- Echinocandins (caspofungin, micafungin, anidulafungin) achieve inadequate urinary concentrations 2, 3
- Newer azoles (voriconazole, posaconazole) do not reach therapeutic urine levels 2
- Lipid formulations of amphotericin B do not attain adequate urinary concentrations 2
Do NOT rely on colony counts or pyuria to distinguish colonization from infection, especially in catheterized patients. 1, 2
In male patients: Do not automatically dismiss candiduria as simple colonization; anatomical factors (prostate, longer urethra) increase likelihood of true infection. 2
Follow-Up and Monitoring
For recurrent candiduria after appropriate treatment, evaluate for underlying urologic abnormalities: 2
- Strictures
- Stones
- Prostatic disease
- Persistent obstruction
Key principle: Candiduria progresses to candidemia in less than 5% of cases, serving primarily as a marker of illness severity rather than a direct cause of morbidity. 1, 2