When should candiduria be treated and what is the recommended first‑line therapy, including alternatives for pregnancy or fluconazole intolerance?

Candiduria Treatment

Asymptomatic candiduria should not be treated in most patients because it represents benign colonization; however, fluconazole 200 mg daily for 14 days is the first-line therapy for symptomatic cystitis, while amphotericin B deoxycholate is the treatment of choice in pregnancy. 1, 2

When to Treat vs. Observe

Asymptomatic Candiduria – Observation Only

• Most asymptomatic patients do not require antifungal therapy because candiduria almost always represents colonization rather than infection, and treatment does not reduce mortality or improve outcomes. 1, 2
• Candiduria progresses to candidemia in less than 5% of cases, serving primarily as a marker of illness severity rather than a cause of morbidity. 2
• Removing the indwelling urinary catheter alone clears candiduria in approximately 50% of cases without any antifungal medication. 1, 2

High-Risk Asymptomatic Patients Requiring Treatment

Despite lack of symptoms, the following groups must receive antifungal therapy:

• Neutropenic patients with persistent unexplained fever and candiduria, due to heightened risk of disseminated candidiasis. 1, 2
• Very low-birth-weight neonates (< 1500 g), who have high propensity for invasive candidiasis. 1, 2
• Patients undergoing urologic procedures or instrumentation within several days, to prevent procedure-related candidemia. 1, 2
• Patients with urinary tract obstruction that cannot be promptly relieved. 2

Symptomatic Candiduria – Always Treat

• Any patient with dysuria, frequency, urgency, suprapubic pain, flank pain, fever, or symptoms of prostatitis requires antifungal therapy. 2, 3

First-Line Management: Non-Pharmacologic Interventions

Before initiating antifungals, address predisposing factors:

• Immediately remove any indwelling urinary catheter – this is the single most important intervention and resolves candiduria in ~50% of cases without drugs. 1, 2
• Discontinue unnecessary broad-spectrum antibiotics, which are a major risk factor for candiduria. 2
• Eliminate urinary tract obstruction to facilitate infection clearance. 1
• Remove or replace nephrostomy tubes or ureteral stents when present. 1

Pharmacologic Treatment Regimens

Symptomatic Candida Cystitis (Lower UTI)

For fluconazole-susceptible species:

• Fluconazole 200 mg (3 mg/kg) orally once daily for 14 days is the preferred first-line regimen, based on the only randomized, double-blind, placebo-controlled trial demonstrating efficacy. 1, 2, 3
• Fluconazole achieves high urinary concentrations of active drug, ensuring effective pathogen eradication. 1, 2

Symptomatic Candida Pyelonephritis (Upper UTI)

For fluconazole-susceptible organisms:

• Fluconazole 200–400 mg (3–6 mg/kg) orally once daily for 14 days; use the higher 400 mg dose when upper-tract involvement is confirmed. 1, 2
• Suspect pyelonephritis when flank pain, fever > 38.3°C, or systemic manifestations develop. 2

Patients Undergoing Urologic Procedures

For asymptomatic candiduria before instrumentation:

• 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

Treatment of Fluconazole-Resistant Species

Candida glabrata (Often Fluconazole-Resistant)

For cystitis or 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, 2, 3
• Oral flucytosine 25 mg/kg four times daily for 7–10 days as monotherapy may be considered when amphotericin B is unsuitable (weaker recommendation). 2

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, 2, 3

Refractory Fluconazole-Resistant Cystitis

• Bladder irrigation with amphotericin B deoxycholate 50 mg/L sterile water daily for 5 days can be employed, though relapse rates are 80–90%. 2

Special Populations

Pregnancy

• Amphotericin B deoxycholate is the treatment of choice in pregnant women for any invasive candidiasis, including symptomatic candiduria. 1

Neutropenic Patients or Very Low-Birth-Weight Neonates

• Treat as candidemia to prevent dissemination: echinocandin (caspofungin 70 mg loading then 50 mg daily, micafungin 100 mg daily, or anidulafungin 200 mg loading then 100 mg daily) OR lipid formulation amphotericin B 3–5 mg/kg daily for 14 days after documented bloodstream clearance. 1, 2

Complicated Infections Requiring Surgical Intervention

Fungal Balls (Bezoars) or Obstructive Uropathy

• Surgical or endoscopic removal is mandatory in addition to systemic antifungal therapy; antifungal agents alone fail without drainage. 1, 2
• For patients with nephrostomy tubes, adjunctive irrigation with amphotericin B deoxycholate 25–50 mg diluted in 200–500 mL sterile water is recommended. 2

Critical Pitfalls to Avoid

• Do not treat asymptomatic candiduria reflexively in otherwise healthy individuals, diabetic patients without additional high-risk features, or elderly patients lacking other indications – most cases represent benign colonization. 2
• Do not use echinocandins (caspofungin, micafungin, anidulafungin) or newer azoles (voriconazole, posaconazole) for urinary Candida infections because they achieve inadequate urine concentrations. 2, 3, 4
• Do not use lipid formulations of amphotericin B for Candida urinary tract infections because they do not attain adequate urinary levels. 2, 3
• Do not rely on colony counts or pyuria to differentiate colonization from infection, especially in catheterized patients – these markers are unreliable. 2
• In male patients, do not automatically dismiss candiduria as simple colonization; evaluate for possible prostatitis if urinary symptoms develop. 2

Follow-Up and Recurrence

• For recurrent candiduria after appropriate therapy, evaluate for underlying urologic abnormalities such as strictures, stones, prostatic disease, or persistent obstruction. 2
• If urinary symptoms persist beyond 48–72 hours, obtain renal or bladder ultrasound (or CT) to exclude obstruction, fungal balls, or perinephric abscesses. 2