What is the recommended dosing for Diflucan (fluconazole)?

Fluconazole (Diflucan) Dosing Guidelines

Fluconazole dosing varies significantly by indication, ranging from a single 150 mg dose for uncomplicated vaginal candidiasis to 800 mg loading doses for invasive candidiasis in critically ill patients. 1

Dosing by Clinical Indication

Vaginal Candidiasis

• Single dose: 150 mg orally once for uncomplicated cases 1
• For severe or recurrent vaginal candidiasis: Two doses of 150 mg given 3 days apart (day 1 and day 4) achieves superior clinical and mycologic cure rates compared to single-dose therapy 2
• For chronic suppressive therapy after initial control of recurrent infections: 150 mg weekly for 6 months 3

Oropharyngeal Candidiasis (Oral Thrush)

• Mild disease: Topical agents preferred (clotrimazole troches 10 mg 5 times daily for 7-14 days) 4, 5
• Moderate to severe disease:
  • Loading dose: 200 mg on day 1, then 100 mg daily for minimum 7-14 days 1
  • Alternative dosing: 100-200 mg daily for 7-14 days 4, 5
  • Continue for at least 2 weeks to reduce relapse risk 1
• Chronic suppressive therapy (for recurrent infections in immunocompromised patients): 100 mg three times weekly 4, 6, 5

Esophageal Candidiasis

• Loading dose: 200 mg on day 1, then 100 mg daily 1
• Higher doses up to 400 mg daily may be used based on clinical response 4, 1
• Minimum treatment duration: 3 weeks AND at least 2 weeks after symptom resolution 1
• For recurrent esophageal candidiasis: Suppressive therapy with 100-200 mg three times weekly 4, 6

Candidemia and Invasive Candidiasis

• Non-neutropenic ICU patients:
  • Loading dose: 800 mg (12 mg/kg) on day 1, then 400 mg (6 mg/kg) daily 4
  • This regimen is appropriate only in ICUs with >5% invasive candidiasis rates and when echinocandins are not preferred 4
• Duration: Continue for 2 weeks after documented clearance from bloodstream AND resolution of symptoms 4, 3
• Critical caveat: Fluconazole should NOT be used empirically in patients with prior azole prophylaxis 3

Urinary Tract Candidiasis

• Symptomatic cystitis: 200 mg daily for 2 weeks for fluconazole-susceptible organisms 4, 3, 6
• Pyelonephritis: 200-400 mg daily for 2 weeks 3
• Perioperative prophylaxis (for urologic procedures): 400 mg daily for several days before and after the procedure 4, 6
• Remove indwelling catheters whenever possible, as continuing catheters significantly reduces cure rates 3, 6

Cryptococcal Meningitis

• Acute treatment: 400 mg on day 1, then 200-400 mg daily 1
• Duration: 10-12 weeks after cerebrospinal fluid becomes culture negative 1
• Suppressive therapy (AIDS patients): 200 mg daily 1

Prophylaxis in Bone Marrow Transplant

• 400 mg daily starting several days before anticipated neutropenia, continuing for 7 days after neutrophil count rises above 1000 cells/mm³ 1

Pediatric Dosing

Dose Equivalency

• 3 mg/kg pediatric dose ≈ 100 mg adult dose
• 6 mg/kg pediatric dose ≈ 200 mg adult dose
• 12 mg/kg pediatric dose ≈ 400 mg adult dose 1
• Maximum absolute dose: 600 mg/day 1

Specific Pediatric Indications

• Oropharyngeal candidiasis: 6 mg/kg loading dose, then 3 mg/kg daily for at least 2 weeks 1
• Esophageal candidiasis: 6 mg/kg loading dose, then 3 mg/kg daily (up to 12 mg/kg/day based on response) for minimum 3 weeks 1
• Cryptococcal meningitis: 12 mg/kg loading dose, then 6-12 mg/kg daily 1

Neonatal Dosing

• Premature neonates (26-29 weeks gestational age): Same mg/kg dose as older children but administered every 72 hours for first 2 weeks of life, then once daily thereafter 1
• Disseminated candidiasis in neonates: 12 mg/kg IV or oral daily is a reasonable alternative to amphotericin B in patients without prior fluconazole prophylaxis 4

Renal Dosing Adjustments

Loading Dose

• Give full loading dose (50-400 mg based on indication) regardless of renal function 1

Maintenance Dosing by Creatinine Clearance

• CrCl >50 mL/min: 100% of recommended dose 1
• CrCl ≤50 mL/min (no dialysis): 50% of recommended dose 1
• Hemodialysis patients: 100% of recommended dose after each dialysis session; on non-dialysis days, give reduced dose per creatinine clearance 6, 1

Critical Pitfalls to Avoid

Treatment Duration Errors

• Inadequate treatment duration is the most common cause of recurrence 3, 5
• Complete the full course even if symptoms resolve early 3
• For candidemia, continue for 2 weeks AFTER blood culture clearance, not from treatment initiation 4, 3

Resistance Considerations

• C. glabrata may develop resistance during therapy; monitor clinical response closely 3, 6
• Do not use fluconazole for empiric therapy in patients with prior azole prophylaxis 3
• Non-albicans Candida species predict significantly reduced response regardless of therapy duration 2

Catheter Management

• Central venous catheter removal is strongly recommended for candidemia 4
• Remove indwelling urinary catheters whenever feasible for urinary tract candidiasis 4, 6
• Continuing catheters during treatment significantly reduces cure rates 3, 6

Fluconazole-Refractory Disease

For patients failing fluconazole therapy:

• Oropharyngeal/esophageal: Switch to itraconazole solution 200 mg daily, posaconazole suspension 400 mg twice daily, or voriconazole 200 mg twice daily 4, 5
• Urinary tract (C. glabrata): Switch to amphotericin B deoxycholate 0.3-0.6 mg/kg daily or flucytosine 25 mg/kg four times daily 4
• Consider IV echinocandin for severe refractory cases 4

Special Population Considerations

• HIV/AIDS patients: Antiretroviral therapy is essential to reduce recurrent infections; chronic suppressive antifungal therapy alone is insufficient 4, 5
• Denture-related candidiasis: Disinfection of dentures is mandatory in addition to antifungal therapy; remove dentures at night 4, 5
• ICU patients: Fluconazole is only appropriate for empiric therapy in units with >5% invasive candidiasis rates; echinocandins are generally preferred 4