What is the recommended dosage of fluconazole (Diflucan) for treating candida infections?

Fluconazole Dosing for Candida Infections

For treating candida infections, fluconazole should be administered with a loading dose of 800 mg (12 mg/kg), followed by 400 mg (6 mg/kg) daily for most invasive infections, with specific adjustments based on infection site and severity. 1

Dosing Recommendations by Infection Type

Invasive Candidiasis/Candidemia

• Initial therapy: Loading dose of 800 mg (12 mg/kg), then 400 mg (6 mg/kg) daily 1
• Duration: At least 2 weeks after documented clearance of Candida from bloodstream 1
• Alternative: For moderately severe to severe illness or recent azole exposure, consider an echinocandin instead 1

Oropharyngeal Candidiasis

• Mild disease: 100-200 mg daily for 7-14 days 1
• Moderate to severe disease: 200 mg on first day, then 100 mg daily for 7-14 days 2

Esophageal Candidiasis

• Standard regimen: 200 mg on first day, followed by 100 mg daily 2
• Severe cases: Doses up to 400 mg daily may be used 2
• Duration: Minimum 3 weeks and at least 2 weeks following symptom resolution 2

Vaginal Candidiasis

• Uncomplicated: Single 150 mg dose 1
• Recurrent: 10-14 days induction with topical or oral azole, followed by 150 mg weekly for 6 months 1

Urinary Tract Candidiasis

• Standard regimen: 200 mg (3 mg/kg) daily for 2 weeks for fluconazole-susceptible organisms 1
• Urologic procedures: 400 mg (6 mg/kg) daily for several days before and after the procedure 1

Special Considerations

Candida Species Considerations

• C. albicans: Generally susceptible to standard fluconazole doses 1
• C. glabrata: Higher doses (800 mg daily) often recommended, but efficacy is lower (50%) 1, 3
• C. krusei: Intrinsically resistant to fluconazole; alternative antifungals should be used 3
• C. parapsilosis: Highly responsive to fluconazole (93% efficacy) 3

Patient-Specific Adjustments

Renal Impairment

• Creatinine clearance >50 mL/min: 100% of recommended dose
• Creatinine clearance ≤50 mL/min (no dialysis): 50% of recommended dose
• Hemodialysis: 100% of recommended dose after each hemodialysis 2

Pediatric Dosing

• Oropharyngeal candidiasis: 6 mg/kg on first day, then 3 mg/kg daily
• Esophageal candidiasis: 6 mg/kg on first day, then 3 mg/kg daily (up to 12 mg/kg/day)
• Systemic infections: 6-12 mg/kg/day 2

Treatment Duration

• Candidemia: Minimum 2 weeks after blood culture clearance 1
• Esophageal candidiasis: Minimum 3 weeks and at least 2 weeks after symptom resolution 2
• Oropharyngeal candidiasis: Minimum 7-14 days 4

Common Pitfalls and Caveats

• Fluconazole has poor activity against C. glabrata and no activity against C. krusei; identify species before committing to fluconazole therapy 1, 3
• Fluconazole has significant drug interactions through cytochrome P450 inhibition; review patient's medication list before prescribing 1
• For patients with recent azole exposure or critical illness, an echinocandin is preferred for initial therapy 1
• Inadequate dosing is a common cause of treatment failure; use appropriate loading doses for invasive infections 1
• CSF and vitreous penetration of fluconazole is excellent (>70% of serum concentration), making it suitable for CNS and ocular candidiasis 1

Fluconazole's excellent bioavailability (90%) means oral and intravenous doses are essentially equivalent, allowing for easy transition between routes of administration 1.