What is the dose of Diflucan (fluconazole) for treating fungal infections?

Fluconazole Dosing for Fungal Infections

Fluconazole dosing varies by infection type and severity, ranging from a single 150 mg dose for vaginal candidiasis to 400-800 mg daily for life-threatening systemic infections. 1

Vaginal Candidiasis

• Single dose of 150 mg orally is the standard treatment 1
• This achieves 88% long-term cure rates and 97% short-term clinical response 2

Oropharyngeal Candidiasis

• Loading dose: 200 mg on day 1 1
• Maintenance: 100 mg once daily for 7-14 days 1, 3
• Topical agents are preferred first-line for mild disease; fluconazole is reserved for moderate-to-severe cases 3, 4
• Continue treatment for at least 2 weeks to decrease relapse risk 1

Esophageal Candidiasis

• Loading dose: 200 mg on day 1 1
• Maintenance: 100 mg once daily, up to 400 mg daily based on severity 1, 3
• Treat for minimum 14-21 days and at least 2 weeks after symptom resolution 5, 3

Systemic Candidiasis (Candidemia, Disseminated Disease)

• Standard dose: 400 mg (6 mg/kg) daily 5, 3, 4
• Loading dose: 800 mg (12 mg/kg) on day 1 5
• Continue for 2 weeks after first negative blood culture and symptom resolution 5
• Central venous catheter removal is strongly recommended 4

Urinary Tract Infections

Symptomatic Cystitis

• 200 mg (3 mg/kg) daily for 14 days 5, 3

Pyelonephritis

• 200-400 mg (3-6 mg/kg) daily for 14 days 5, 3
• If disseminated candidiasis is suspected, treat as candidemia 5

Asymptomatic Cystitis

• Therapy usually not indicated unless high-risk patients (neonates, neutropenic, undergoing urologic procedures) 5

CNS Candidiasis

• 400-800 mg (6-12 mg/kg) daily for patients unable to tolerate amphotericin B 5
• Treat until all clinical signs, CSF abnormalities, and radiologic findings resolve 5
• Remove intraventricular devices 5

Cryptococcal Meningitis

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

Chronic Disseminated Candidiasis

• 400 mg (6 mg/kg) daily for stable patients 5
• Continue until lesions resolve (typically 3-6 months) 5
• Can transition from amphotericin B to fluconazole after clinical stabilization 5

Pediatric Dosing

• 3 mg/kg ≈ 100 mg adult dose 1, 4
• 6 mg/kg ≈ 200 mg adult dose 1, 4
• 12 mg/kg ≈ 400 mg adult dose 1
• Maximum daily dose: 600 mg (doses exceeding this are not recommended) 1

Critical Caveats and Pitfalls

Species-Specific Resistance

• Fluconazole has NO activity against Candida krusei 3
• Variable activity against C. glabrata—confirm susceptibility before use 5, 3
• For fluconazole-resistant species, use alternative antifungals (echinocandins, amphotericin B, voriconazole) 5, 4

Respiratory Colonization

• Candida isolated from respiratory secretions usually represents colonization, NOT infection 3, 4
• Rarely requires treatment unless histopathologic evidence confirms invasive disease 5

Loading Dose Strategy

• A loading dose of twice the daily dose on day 1 achieves near-steady-state concentrations by day 2 1
• This is particularly important for serious infections requiring rapid therapeutic levels 1

Duration Considerations

• Inadequate treatment duration leads to relapse—continue until clinical and laboratory parameters indicate resolution 1
• AIDS patients with cryptococcal meningitis or recurrent oropharyngeal candidiasis require lifelong maintenance therapy 1