From the Guidelines
Fluconazole dosage for urinary tract infections (UTIs) caused by susceptible Candida species is 200-400 mg (3-6 mg/kg) daily for 2 weeks, as recommended by the Infectious Diseases Society of America 1. When considering treatment for fungal UTIs, it's essential to note that fluconazole is not the first-line treatment for most UTIs, which are typically caused by bacteria. However, for fungal UTIs, fluconazole is effective due to its ability to inhibit fungal cell membrane synthesis, specifically targeting ergosterol production, and it achieves high concentrations in the urinary tract 1. Key considerations for treatment include:
- Confirming the fungal infection through urine culture before starting fluconazole, as antibiotics are more appropriate for bacterial infections 1
- Administering fluconazole with or without food at the same time each day and completing the full course even if symptoms improve
- Potential adjustment of the treatment duration based on the severity of the infection, with complicated fungal UTIs possibly requiring extended treatment 1
- Removal of urinary tract obstructions and consideration of removing or replacing nephrostomy tubes or stents if feasible, as recommended by clinical guidelines 1
From the FDA Drug Label
Urinary tract infections and peritonitis: For the treatment of Candida urinary tract infections and peritonitis, daily doses of 50 to 200 mg have been used in open, noncomparative studies of small numbers of patients. The recommended dosage of fluconazole for UTI is 50 to 200 mg daily 2.
- The dosage may vary based on the patient's response to therapy and the severity of the infection.
- The optimal therapeutic dosage and duration of therapy have not been established for systemic Candida infections, but for Candida urinary tract infections, doses within this range have been used.
From the Research
Fluconazole Dosage for UTI
- The recommended dosage of fluconazole for the treatment of symptomatic fungal urinary tract infection (UTI) is a 200-mg loading dose followed by 100 mg/d for at least four days 3.
- This dosage is considered the most appropriate for patients without systemic fungal infection or severe renal failure 3.
- Fluconazole is the treatment of choice for symptomatic infections, as it achieves high urinary levels 4, 5.
- The use of fluconazole is supported by several studies, which have demonstrated its effectiveness in treating both uncomplicated and complicated fungal urinary tract infections 3, 5, 6.
Treatment Options
- Fluconazole is the antifungal agent of choice for treating Candida urinary tract infections, due to its ability to achieve high urine concentrations with oral formulation 4, 5.
- Alternative treatment options, such as amphotericin B, may be considered in cases where fluconazole is not effective or cannot be used due to resistance, allergy, or failure 4, 5.
- Newer azole agents and echinocandins are not recommended for the treatment of urinary tract infections, as they fail to achieve adequate urine concentrations 5.
Important Considerations
- The presence of Candida species in urine does not necessarily indicate a urinary tract infection, and treatment should only be initiated in symptomatic patients or those at high risk of developing systemic fungal infections 4, 6.
- Removing predisposing factors, such as indwelling catheters and antibiotics, can help clear candiduria in asymptomatic patients 5.