What is the recommended dose of fluconazole (Diflucan) for yeast infection prophylaxis?

Fluconazole Dosing for Yeast Infection Prophylaxis

For yeast infection prophylaxis, fluconazole 100-400 mg once weekly is the recommended dosing regimen, with 200 mg once weekly being the most commonly used dose for most patients.

Dosing Recommendations by Patient Population

Immunocompromised Patients

• HIV/AIDS patients:

  • Fluconazole 200 mg once weekly for chronic suppressive therapy 1
  • For recurrent oropharyngeal candidiasis: 100 mg three times weekly 1

• Neutropenic patients (chemotherapy-induced):

  • Fluconazole 400 mg daily during induction chemotherapy for duration of neutropenia 1
  • Alternative: 400 mg once weekly has shown efficacy but with higher rates of thrush than daily dosing 2, 3

• Stem cell transplant recipients:

  • Fluconazole 400 mg daily during the period of neutropenia 1
  • Start several days before anticipated onset of neutropenia
  • Continue for 7 days after neutrophil count rises above 1000 cells/mm³ 4

Solid Organ Transplant Recipients

• Fluconazole 200-400 mg (3-6 mg/kg) daily for 7-14 days is recommended for:
  • Liver transplant recipients (high-quality evidence) 1
  • Pancreas transplant recipients (moderate-quality evidence) 1
  • Small bowel transplant recipients (low-quality evidence) 1

ICU Patients

• Fluconazole 400 mg (6 mg/kg) daily for high-risk patients in adult ICUs with high incidence (>5%) of invasive candidiasis 1

Clinical Considerations for Prophylaxis

Duration of Prophylaxis

• For neutropenic patients: Continue until neutrophil recovery 4
• For HIV patients: Long-term suppression may be necessary 1
• For transplant patients: 7-14 days post-procedure 1

Monitoring During Prophylaxis

• Monitor liver function tests periodically
• Be alert for breakthrough infections with fluconazole-resistant species (particularly C. glabrata and C. krusei)
• Consider drug interactions, especially with medications metabolized through CYP450 enzymes

Common Pitfalls to Avoid

1. Inadequate dosing: Weekly dosing should be at least 200 mg to maintain adequate protection
2. Failure to recognize breakthrough infections: Patients on prophylaxis can still develop infections with resistant species
3. Drug interactions: Fluconazole has significant interactions with immunosuppressants, anticoagulants, and other medications
4. Prolonged unnecessary use: Reassess the need for prophylaxis regularly to minimize resistance development

Special Populations

Neonates

• In nurseries with high rates (>10%) of invasive candidiasis, fluconazole 3-6 mg/kg twice weekly is recommended 1

Patients with Renal Impairment

• Dose adjustment required for creatinine clearance <50 mL/min
• For patients on dialysis, consider 100 mg orally or 50 mg intraperitoneally for CAPD patients 5

The evidence strongly supports weekly fluconazole prophylaxis as an effective strategy for preventing invasive fungal infections in high-risk patients, with efficacy comparable to daily dosing in many populations 2, 3.