What is the recommended dose of fluconazole (Fluconazole) for a patient with impaired renal function (GFR 36) and yeast in urine?

From the Guidelines

For a patient with impaired renal function (GFR 36) and yeast in urine, the recommended dose of fluconazole should be adjusted to 50% of the standard dose, which is 100-200 mg once daily, as fluconazole is primarily eliminated by the kidneys and reduced renal function leads to drug accumulation and potential toxicity 1. The standard dose of fluconazole for yeast infections is 200-400 mg daily, but for patients with impaired renal function, a dose reduction is necessary to avoid toxicity.

• The medication's half-life is significantly prolonged in patients with renal impairment, so reducing the dose helps maintain therapeutic levels while minimizing adverse effects.
• It's essential to monitor the patient for side effects such as nausea, headache, abdominal pain, and elevated liver enzymes during treatment.
• Adequate hydration should also be encouraged to help with drug clearance and to manage the urinary infection. According to the clinical practice guideline for the management of candidiasis, oral fluconazole, 200 mg (3 mg/kg) daily for 2 weeks is recommended for fluconazole-susceptible organisms 1. However, for patients with impaired renal function, the dose should be adjusted based on the patient's renal function, and the recommended dose reduction is 50% of the standard dose when GFR < 45 ml/min/1.73 m2 1. In this case, the patient's GFR is 36, which is less than 45, so the dose reduction is necessary. The patient should be treated with 100 mg daily for 7-14 days, and the treatment should be monitored closely for any adverse effects. It's also important to note that removal of an indwelling bladder catheter, if feasible, is strongly recommended, and AmB deoxycholate bladder irrigation may be useful for treatment of cystitis due to fluconazole-resistant species 1.

From the FDA Drug Label

Dosage In Patients With Impaired Renal Function: Fluconazole is cleared primarily by renal excretion as unchanged drug. ... In patients with impaired renal function who will receive multiple doses of fluconazole tablets, an initial loading dose of 50 mg to 400 mg should be given After the loading dose, the daily dose (according to indication) should be based on the following table: Creatinine Clearance (mL/min) Recommended Dose (%) >50 100 ≤50 (no dialysis) 50

Although the pharmacokinetics of fluconazole has not been studied in children with renal insufficiency, dosage reduction in children with renal insufficiency should parallel that recommended for adults.

To estimate the creatinine clearance, we use the formula for adults: Males: Weight (kg) x (140 - age) ————————————— 72 x serum creatinine (mg/100 mL) Females: 0. 85 × above value However, the patient's sex, weight, age, and serum creatinine are not provided.

Given the patient's GFR is 36, which corresponds to ≤50 (no dialysis), the recommended dose is 50% of the standard dose. The standard dose for yeast in urine is not explicitly stated in the label for this specific condition, but for other conditions such as systemic candida, the dose is 6 to 12 mg/kg/day.

Assuming a dose of 6 to 12 mg/kg/day for yeast in urine and a 50% reduction due to impaired renal function, the dose would be 3 to 6 mg/kg/day. However, without the patient's weight, we cannot determine the exact dose in milligrams.

For a patient with a GFR of 36, the dose of fluconazole for yeast in urine should be 50% of the standard dose, but the exact dose in milligrams cannot be determined without more information 2.

From the Research

Dosage of Fluconazole for Yeast in Urine

• The recommended dose of fluconazole for a patient with impaired renal function (GFR 36) and yeast in urine is not explicitly stated in the provided studies.
• However, it is known that fluconazole achieves high urinary levels, making it a suitable treatment option for symptomatic candiduria 3.
• The dosage and duration of fluconazole therapy have not been established, but it is considered the agent of first choice for susceptible fungi 4.
• In patients with impaired renal function, the dose of fluconazole may need to be adjusted to avoid accumulation of the drug and potential toxicity.
• A study on the in vitro activities of voriconazole, fluconazole, itraconazole, and amphotericin B against non-Candida albicans yeast isolates found that fluconazole had activity against these isolates, but the MICs were not specifically determined for patients with impaired renal function 5.
• Another study evaluated the antifungal activity of amphotericin B, fluconazole, and voriconazole in an in vitro model of Candida catheter-related bloodstream infection, and found that fluconazole suppressed fungal counts, but the dose used was 400 mg or 800 mg every 24 hours 6.

Considerations for Patients with Impaired Renal Function

• Patients with impaired renal function (GFR 36) may require dose adjustments for fluconazole to avoid potential toxicity 3, 4.
• The studies provided do not specifically address the dosage of fluconazole for patients with impaired renal function and yeast in urine.
• It is essential to consider the patient's renal function and other factors, such as the severity of the infection and the presence of other medical conditions, when determining the appropriate dose of fluconazole.
• Fluconazole is the treatment of choice for symptomatic infections, and it achieves high urinary levels, but the dosage and duration of therapy have not been established 3, 4.