What is the recommended treatment for a patient with a positive yeast urine culture, particularly those with underlying medical conditions such as diabetes?

Treatment of Yeast Urine Culture

Most patients with yeast in their urine do not require antifungal treatment unless they are symptomatic or belong to specific high-risk groups. 1, 2

Initial Assessment: Does This Patient Need Treatment?

The critical first step is determining whether candiduria represents colonization (most common) or true infection requiring therapy. 1

DO NOT TREAT if the patient is asymptomatic and lacks high-risk features 1, 2

• Asymptomatic candiduria resolves spontaneously in 76% of untreated cases 2
• Treatment of asymptomatic low-risk patients provides no benefit and promotes resistance 2
• Simply removing the urinary catheter (if present) eliminates candiduria in approximately 50% of cases without antifungals 1, 3

DO TREAT if any of the following apply:

Symptomatic infection: 1, 2

• Cystitis symptoms: dysuria, frequency, urgency, suprapubic pain
• Pyelonephritis symptoms: fever, flank pain, costovertebral angle tenderness

High-risk patient groups requiring treatment even if asymptomatic: 1, 2

• Neutropenic patients (treat as candidemia)
• Very low birth weight infants <1500g (treat as candidemia)
• Patients undergoing urologic procedures/manipulation within days
• Suspected disseminated candidiasis

Patients with diabetes mellitus and candiduria: These patients require treatment only if symptomatic; diabetes alone does not mandate treatment of asymptomatic candiduria. 4, 5

Treatment Regimens for Symptomatic Cystitis

First-line: Fluconazole (for fluconazole-susceptible species) 1

• Oral fluconazole 200 mg (3 mg/kg) daily for 14 days
• Fluconazole is the drug of choice because it achieves high urinary concentrations in active form 1, 4
• Recent data suggest 7 days may be as effective as 14 days, though guidelines still recommend 14 days 6

For fluconazole-resistant C. glabrata: 1

• 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
• Amphotericin B bladder irrigation (50 mg/L sterile water daily for 5 days) may be considered as adjunct therapy 1

For C. krusei (intrinsically fluconazole-resistant): 1, 2

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

Treatment Regimens for Symptomatic Pyelonephritis

First-line: Fluconazole (for susceptible organisms) 1

• Oral fluconazole 200-400 mg (3-6 mg/kg) daily for 14 days

For fluconazole-resistant C. glabrata: 1

• Amphotericin B deoxycholate 0.5-0.7 mg/kg IV daily for 14 days with or without flucytosine 25 mg/kg four times daily OR
• Flucytosine monotherapy 25 mg/kg four times daily for 14 days (weaker recommendation)

For C. krusei: 1

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

Prophylaxis for Urologic Procedures

Patients with candiduria undergoing urologic manipulation require prophylaxis: 1

• Fluconazole 400 mg (6 mg/kg) daily OR
• Amphotericin B deoxycholate 0.3-0.6 mg/kg daily
• Administer for several days before AND after the procedure

Critical Management Principles

Remove predisposing factors first 1, 2

• Remove indwelling urinary catheter if feasible (strong recommendation—often more important than antifungals)
• Discontinue unnecessary broad-spectrum antibiotics
• Optimize diabetes control if applicable
• Relieve urinary tract obstruction

Drugs that DO NOT work for urinary tract infections 2, 4, 3

• Echinocandins (caspofungin, micafungin, anidulafungin): Achieve inadequate urinary concentrations; not recommended for isolated UTI
• Lipid formulations of amphotericin B: Poor urine concentrations; should be avoided for isolated UTI
• Other azoles (voriconazole, posaconazole, itraconazole): Minimal active drug excretion in urine

Only three antifungals achieve adequate urinary levels 2, 4

• Fluconazole (first choice)
• Amphotericin B deoxycholate
• Flucytosine

Common Pitfalls to Avoid

Treating asymptomatic candiduria in low-risk patients: This is the most common error—provides no benefit and promotes antifungal resistance. 2, 3

Using echinocandins for cystitis: These drugs fail to achieve therapeutic urine concentrations despite being excellent for candidemia. 2, 3

Forgetting to remove the catheter: Catheter removal alone may be curative and is often more important than antifungal therapy. 1, 2, 3

Assuming all candiduria requires 14 days of treatment: While guidelines recommend 14 days, emerging evidence suggests shorter durations (7 days) may be equally effective for uncomplicated cystitis. 6

Using lipid amphotericin formulations for UTI: These achieve poor urinary concentrations and have documented treatment failures in pyelonephritis. 1, 2