What are the dosing instructions for Diflucan (fluconazole)?

Fluconazole (Diflucan) Dosing Instructions

Fluconazole dosing varies significantly by infection type and severity, ranging from a single 150 mg dose for vaginal candidiasis to 400-800 mg daily for serious systemic infections, with treatment duration extending from one day to several months depending on the clinical scenario. 1

Dosing by Indication

Vaginal Candidiasis

• Single dose of 150 mg orally is the standard treatment for uncomplicated vaginal candidiasis 1, 2
• For recurrent vulvovaginal candidiasis, use fluconazole 150 mg weekly for 6 months after initial control of the episode 3

Oropharyngeal Candidiasis (Oral Thrush)

• Mild cases: Start with topical agents (clotrimazole troches 10 mg 5 times daily for 7-14 days) before systemic therapy 4
• Moderate to severe cases: Fluconazole 100-200 mg daily for 7-14 days 3, 4
• Standard FDA-approved regimen: 200 mg on day 1, then 100 mg daily for at least 2 weeks 1
• Chronic suppression (for recurrent infections with ongoing immunosuppression): 100 mg three times weekly 5, 4

Esophageal Candidiasis

• Initial treatment: 200 mg on day 1, followed by 100 mg once daily 1
• Doses up to 400 mg daily may be used based on clinical response 1
• Treat for minimum of 3 weeks and at least 2 weeks after symptom resolution 1
• Suppressive therapy for recurrent disease: 100-200 mg three times weekly 5

Urinary Tract Candidiasis

• Asymptomatic cystitis: Generally no treatment needed unless high-risk patient (neutropenic, neonate, or undergoing urologic procedure) 3
• Symptomatic cystitis: 200 mg daily for 2 weeks 3, 5
• Pyelonephritis: 200-400 mg daily for 2 weeks 3
• For urologic procedures: 400 mg daily for several days before and after the procedure 5

Candidemia and Disseminated Candidiasis

• Doses of 400 mg daily have been used, though optimal dosing is not fully established 1
• Treatment duration: 2 weeks after documented clearance from bloodstream and resolution of symptoms 3
• Central venous catheter removal is strongly recommended 3

Cryptococcal Meningitis

• Acute treatment: 400 mg on day 1, then 200 mg daily (or up to 400 mg daily based on response) 1
• Duration: 10-12 weeks after CSF becomes culture negative 1
• Suppressive therapy (for AIDS patients): 200 mg once daily 1

Prophylaxis in Bone Marrow Transplant

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

Pediatric Dosing

Dose Equivalency (Pediatric to Adult)

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

Specific Pediatric Indications

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

Renal Impairment Dosing

Loading Dose

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

Maintenance Dosing

• CrCl >50 mL/min: 100% of recommended dose 1
• CrCl ≤50 mL/min (no dialysis): 50% of recommended dose 1
• Hemodialysis: 100% of recommended dose after each dialysis session 1
• On non-dialysis days, hemodialysis patients should receive reduced dose according to creatinine clearance 1

Administration Details

• Can be taken with or without food 1
• Available as oral tablets and intravenous formulation 1
• Excellent oral bioavailability (>93%) 6

Critical Pitfalls to Avoid

Treatment Duration

• Inadequate treatment duration is a common cause of recurrence—ensure full course completion even if symptoms resolve early 4
• For oropharyngeal candidiasis, treat for at least 2 weeks to reduce relapse risk 1

Catheter Management

• Remove indwelling catheters whenever possible, as continuing catheters during treatment significantly reduces cure rates 7, 5

Resistance Monitoring

• Monitor for resistance development, particularly with C. glabrata, which may develop resistance during therapy 7, 5
• Do not use fluconazole in patients with prior azole prophylaxis for empiric therapy 3

Inappropriate Prophylaxis

• Do not use fluconazole prophylaxis routinely in immunocompetent patients, as it promotes resistance without proven benefit 7
• Routine prophylaxis with antibiotics alone (e.g., Augmentin) does not warrant fluconazole prophylaxis 7

Denture-Related Candidiasis

• Disinfection of dentures in addition to antifungal therapy is essential—remove dentures at night and clean thoroughly 4