What is the recommended dose of fluconazole (antifungal medication) for various types of candidiasis?

Fluconazole Dosing for Candidiasis

The recommended fluconazole dose varies by infection type: 150 mg single dose for uncomplicated vaginal candidiasis, 200 mg loading dose then 100 mg daily for oropharyngeal candidiasis, 200-400 mg daily for esophageal candidiasis, and 800 mg loading dose then 400 mg daily for invasive candidiasis/candidemia. 1, 2

Invasive Candidiasis and Candidemia

For nonneutropenic adults with candidemia, initiate fluconazole 800 mg (12 mg/kg) loading dose on day 1, followed by 400 mg (6 mg/kg) daily. 1, 3

• Fluconazole is appropriate for patients who are less critically ill and have no recent azole exposure 1
• For moderately severe to severe illness or recent azole exposure, echinocandins are preferred over fluconazole 1
• Continue treatment for 2 weeks after documented clearance from bloodstream and resolution of symptoms 1, 4
• Remove all intravascular catheters if possible, as this significantly improves outcomes 1, 4

For neutropenic patients, the same fluconazole dosing applies (800 mg loading, then 400 mg daily), but only if they lack recent azole exposure and are not critically ill. 1

• Echinocandins or lipid formulation amphotericin B are preferred for most neutropenic patients 1
• Continue therapy for 2 weeks after clearance, symptom resolution, AND neutropenia resolution 1

Species-Specific Considerations

• For Candida glabrata: Do NOT use fluconazole as initial therapy—echinocandins are strongly preferred. 1, 3
• For Candida parapsilosis: Fluconazole is preferred over echinocandins. 1
• For Candida krusei: Avoid fluconazole entirely due to intrinsic resistance; use echinocandins or amphotericin B. 1, 3

Oropharyngeal Candidiasis

Administer fluconazole 200 mg loading dose on day 1, then 100 mg daily for at least 2 weeks. 1, 4, 2

• Continue for minimum 2 weeks even if symptoms resolve earlier to reduce relapse risk 4, 2
• In immunocompromised patients (especially AIDS), relapse rates approach 40% regardless of antifungal used 5
• Maintenance therapy may be necessary in AIDS patients to prevent relapse 2

Esophageal Candidiasis

Give fluconazole 200 mg on day 1, then 100 mg daily, with doses up to 400 mg daily based on clinical response. 1, 4, 2

• Treat for minimum 3 weeks AND at least 2 weeks following symptom resolution 2
• For patients unable to tolerate oral therapy, use IV fluconazole 400 mg daily 4
• Topical agents are inadequate for esophageal disease—systemic therapy is mandatory 4

Vaginal Candidiasis

For uncomplicated vaginal candidiasis, prescribe a single oral dose of fluconazole 150 mg. 3, 2, 6

• Clinical cure rates exceed 90% with single-dose therapy 3, 6, 7
• Short-term cure (5-16 days) reaches 97%, with long-term cure (27-62 days) at 88% 6

For recurrent vulvovaginal candidiasis, use fluconazole 150 mg weekly for 6 months after initial control of the acute episode. 1, 3

Urinary Tract Candidiasis

Asymptomatic Candiduria

• Treatment is NOT usually indicated unless patient is high-risk (neonates, neutropenic adults) or undergoing urologic procedures 1
• For patients undergoing urologic procedures: fluconazole 200-400 mg (3-6 mg/kg) daily for several days before and after the procedure 1

Symptomatic Cystitis

Administer fluconazole 200 mg (3 mg/kg) daily for 2 weeks. 1, 4

Pyelonephritis

Use fluconazole 200-400 mg (3-6 mg/kg) daily for 2 weeks. 1

• If disseminated candidiasis is suspected with pyelonephritis, treat as candidemia 1

Chronic Disseminated Candidiasis (Hepatosplenic)

Give fluconazole 400 mg (6 mg/kg) daily for stable patients. 1

• For severely ill patients, start with lipid formulation amphotericin B or amphotericin B deoxycholate, then transition to fluconazole after stabilization 1
• Duration is typically months, continuing until lesions resolve and through periods of immunosuppression 1

Osteoarticular Infections

Osteomyelitis

Prescribe fluconazole 400 mg (6 mg/kg) daily for 6-12 months. 1

• Surgical debridement is frequently necessary 1
• Consider starting with echinocandin or amphotericin B for several weeks before transitioning to fluconazole 1

Septic Arthritis

Use fluconazole 400 mg (6 mg/kg) daily for at least 6 weeks. 1

• Surgical debridement is recommended for all cases 1
• For infected prosthetic joints, removal is recommended 1

Pediatric Dosing

For children, use the following dose equivalents to achieve similar exposure as adults: 2

• 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 (maximum 600 mg/day) 2

For oropharyngeal candidiasis in children: 6 mg/kg loading dose on day 1, then 3 mg/kg daily for at least 2 weeks. 2

Neonatal Dosing

• Premature newborns (gestational age 26-29 weeks) in first 2 weeks of life: Administer the standard pediatric dose every 72 hours. 2, 8
• Weeks 2-4 of life: Give the same dose every 48 hours. 8
• After 4 weeks: Transition to daily dosing. 2, 8
• The recommended daily dosage for systemic infections is 6 mg/kg 8

Critical Dosing Adjustments

Renal Impairment

For creatinine clearance ≤50 mL/min, reduce the recommended dose to 50%. 3

For hemodialysis patients, administer 100% of the recommended dose after each dialysis session. 3

Pharmacokinetic Advantages

• Oral bioavailability is approximately 90%, making oral and IV dosing equivalent 3, 5
• Absorption is unaffected by food, gastric pH, hypochlorhydria, or gastrointestinal disease 3, 5
• CSF concentrations reach 50-89% of serum levels, ideal for CNS infections 3
• Urine concentrations reach 10-20 times serum levels 3

Critical Pitfalls to Avoid

Do NOT use fluconazole prophylaxis in immunocompetent patients taking antibiotics—it promotes resistance without proven benefit. 3

Avoid fluconazole for suspected C. glabrata or C. krusei infections due to reduced susceptibility; use echinocandins instead. 1, 3

If the patient received azole prophylaxis, do NOT use empiric azole therapy—switch to an echinocandin. 1, 3

Monitor clinical response closely in C. glabrata infections, as resistance may develop during fluconazole therapy. 4

Remove indwelling catheters during treatment, as continuing catheters significantly reduces cure rates. 4