What is the recommended management and treatment regimen for symptomatic Candida cystitis in an adult with normal renal function, including catheter removal and antifungal dosing?

Management of Symptomatic Candida Cystitis

For symptomatic Candida cystitis in adults with normal renal function, remove the indwelling urinary catheter immediately (if present) and treat with oral fluconazole 200 mg (3 mg/kg) daily for 14 days for fluconazole-susceptible species. 1

Critical First Step: Catheter Removal

• Removal of any indwelling bladder catheter is mandatory and must be performed immediately, as this single intervention resolves candiduria in approximately 50% of cases without requiring antifungal therapy 1
• Continuing therapy without catheter removal is the most common cause of treatment failure and recurrence 1, 2
• Elimination of urinary tract obstruction (if present) is equally essential to facilitate infection clearance 1

Species-Specific Antifungal Therapy

Fluconazole-Susceptible Species (C. albicans, most C. tropicalis, C. parapsilosis)

• Oral fluconazole 200 mg (3 mg/kg) once daily for 14 days is the first-line treatment for symptomatic cystitis 1, 2
• This recommendation is based on the only randomized, double-blind, placebo-controlled trial demonstrating efficacy (moderate-quality evidence) 1, 3
• Fluconazole is preferred because it achieves high urinary concentrations of active drug, ensuring effective pathogen eradication 3, 2, 4

Fluconazole-Resistant C. glabrata

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the treatment of choice 1, 2
• Alternative: Oral flucytosine 25 mg/kg four times daily for 7–10 days can be used as monotherapy when amphotericin B is unsuitable (weaker recommendation) 1
• Bladder irrigation with amphotericin B deoxycholate 50 mg/L sterile water daily for 5 days may be employed for refractory cystitis, though relapse rates are high 1

C. krusei (Intrinsically Fluconazole-Resistant)

• Amphotericin B deoxycholate 0.3–0.6 mg/kg IV daily for 1–7 days is the recommended regimen 1, 5
• Fluconazole is completely ineffective due to intrinsic resistance and must never be used 5

Monitoring During Amphotericin B Therapy

• Obtain baseline renal function (serum creatinine, BUN) and electrolytes (potassium, magnesium) before initiating therapy 5
• Monitor renal panel at least twice weekly while on amphotericin B due to nephrotoxicity risk 5
• Check complete blood count weekly because amphotericin B can cause anemia 5
• Pre-hydrate with normal saline to mitigate nephrotoxicity 5
• Amphotericin B deoxycholate requires no dose reduction in renal impairment 5

Agents to Avoid for Urinary Tract Infections

• Never use echinocandins (caspofungin, micafungin, anidulafungin) for UTIs—they achieve minimal urinary concentrations and are ineffective 3, 5, 2, 4
• Avoid lipid formulations of amphotericin B (liposomal, lipid complex) for UTIs—they do not attain adequate urine levels 5
• Do not use newer azoles (voriconazole, posaconazole) for urinary infections—insufficient urine concentrations 3, 2, 4

When NOT to Treat: Asymptomatic Candiduria

• Asymptomatic candiduria should not be treated in most patients, as it almost always represents colonization rather than infection 1, 3
• Treatment does not reduce mortality rates or prevent complications in asymptomatic patients 3
• Candiduria progresses to candidemia in less than 5% of cases 3

High-Risk Exceptions Requiring Treatment Despite Lack of Symptoms

• Neutropenic patients with persistent unexplained fever and candiduria 1, 3, 5
• Very low-birth-weight neonates (<1500 g) 1, 3, 5
• Patients undergoing urologic procedures or instrumentation—treat with fluconazole 400 mg (6 mg/kg) daily for several days before and after the procedure 1, 3

Treatment Endpoints and Follow-Up

• Continue therapy until symptoms resolve (dysuria, frequency, urgency, suprapubic pain) 5
• Total duration of 14 days is recommended for both cystitis and pyelonephritis 1, 5
• Obtain repeat urine cultures to document clearance and verify negative cultures after completing therapy 2

Common Pitfalls to Avoid

• Do not treat asymptomatic candiduria reflexively—most cases represent benign colonization 3
• Do not assume diabetes or advanced age alone mandates treatment—these are risk factors but not indications in asymptomatic patients 3
• Do not continue indwelling catheters during treatment—failure to remove them is linked to treatment failure 1, 3, 2
• Colony counts and pyuria are unreliable for distinguishing colonization from infection in catheterized patients 3