Treatment of Candiduria in Patients with Azole Allergy
For patients allergic to azole antifungals, 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) is the treatment of choice for symptomatic Candida urinary tract infections. 1
Initial Assessment: Determine if Treatment is Actually Needed
Before initiating any antifungal therapy, recognize that most candiduria represents benign colonization and does not require treatment—even in patients who cannot receive azoles. 1
Non-Pharmacologic Management (First-Line for All Patients)
- Remove any indwelling urinary catheter immediately—this single intervention clears candiduria in approximately 50% of cases without any antifungal drugs. 1, 2
- Discontinue unnecessary broad-spectrum antibiotics, as these are major drivers of candiduria. 1
- Eliminate urinary tract obstruction and remove or replace nephrostomy tubes or ureteral stents when present. 1
High-Risk Populations Requiring Treatment Despite Lack of Symptoms
Even without azole options, you must treat asymptomatic candiduria in: 1
- Neutropenic patients with persistent unexplained fever and candiduria (risk of disseminated candidiasis)
- Very low-birth-weight neonates (<1500 g)
- Patients undergoing urologic procedures or instrumentation within several days
- Patients with urinary tract obstruction that cannot be promptly relieved
Treatment Regimens for Symptomatic Infections
Symptomatic Candida Cystitis (Lower UTI)
- Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the primary alternative when fluconazole cannot be used. 1, 2
- Oral flucytosine 25 mg/kg four times daily for 7–10 days can be added to amphotericin B or used as monotherapy (weaker recommendation for monotherapy). 1
- For refractory cystitis, bladder irrigation with amphotericin B deoxycholate 50 mg/L sterile water daily for 5 days may be employed, though relapse rates are high (80–90%). 1, 3
Symptomatic Candida Pyelonephritis (Upper UTI)
- Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily with or without oral flucytosine 25 mg/kg four times daily for 14 days total is recommended. 4
- If percutaneous access to the renal collecting system is available, adjunctive irrigation with amphotericin B deoxycholate 25–50 mg diluted in 200–500 mL sterile water can be added to systemic therapy. 1, 4
Pre-Procedure Prophylaxis
- For patients undergoing urologic procedures who cannot receive azoles, use amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for several days before and after the procedure. 1, 5
Species-Specific Considerations
- Candida glabrata is often fluconazole-resistant, making amphotericin B the logical choice regardless of allergy status. 1, 5
- Candida krusei is intrinsically fluconazole-resistant; amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the treatment of choice. 1
Treatment Duration
- Cystitis: 1–7 days of IV amphotericin B (or 7–10 days of oral flucytosine) 1
- Pyelonephritis: 14 days total 4
- Continue therapy until symptoms resolve and urine cultures no longer yield Candida species. 4
Critical Pitfalls to Avoid
- Do not use lipid formulations of amphotericin B for Candida urinary tract infections—they do not achieve adequate urinary concentrations and treatment failures are well-documented. 4, 6
- Do not use echinocandins (caspofungin, micafungin, anidulafungin) for urinary Candida infections—they achieve inadequate urine concentrations and are ineffective for lower tract infections. 1, 7, 6 While one retrospective study showed some success with micafungin 8, guideline recommendations explicitly advise against echinocandins due to poor urinary penetration. 1
- Do not use newer azoles (voriconazole, posaconazole) as alternatives—they also fail to achieve sufficient urine concentrations. 1, 7
- For severely immunocompromised patients with fever and candiduria, treat as disseminated candidiasis with an echinocandin systemically (not for the urinary infection itself), as this may represent candidemia rather than isolated UTI. 4