How often should Diflucan (fluconazole) be taken for a yeast infection?

Diflucan (Fluconazole) Dosing for Yeast Infections

For uncomplicated vaginal yeast infections, take a single 150 mg oral dose of Diflucan once—no repeat dosing is needed. 1, 2

Standard Single-Dose Regimen (Uncomplicated Infection)

• One 150 mg tablet taken orally one time is the FDA-approved and guideline-recommended treatment for uncomplicated vaginal candidiasis, achieving clinical cure rates exceeding 90%. 3, 1, 2
• This single dose provides efficacy equivalent to multi-day topical treatments while offering superior convenience and faster symptom relief. 1, 4
• Clinical improvement should be evident within 5-16 days; mycologic eradication occurs in 72-93% of patients. 5, 6

Uncomplicated infection is defined as: mild-to-moderate symptoms (pruritus, discharge), sporadic episodes (not recurrent), likely Candida albicans, and immunocompetent host (no HIV, uncontrolled diabetes, or immunosuppression). 1

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Multi-Dose Regimens (When Single Dose Is NOT Enough)

Severe Acute Infection

• Fluconazole 150 mg every 72 hours for 3 doses (total 450 mg over 6 days) is required for extensive vulvar erythema, edema, excoriation, or fissures. 3, 1, 5
• Alternative: topical azole therapy for 7-14 days. 5, 7

Recurrent Vulvovaginal Candidiasis (≥4 Episodes Per Year)

Induction Phase:

• Fluconazole 150 mg every 72 hours for 3 doses, OR topical azole for 10-14 days to achieve initial mycologic remission. 3, 1, 5

Maintenance Phase:

• Fluconazole 150 mg once weekly for 6 months after induction. 3, 1, 8
• This regimen keeps >90% of women disease-free during the 6-month treatment period. 5, 8
• At 12 months (6 months after stopping), 42.9% remain disease-free versus 21.9% with placebo; median time to recurrence is 10.2 months versus 4.0 months. 5, 8
• Critical caveat: 30-50% experience recurrence after discontinuing maintenance therapy, making long-term cure difficult. 5, 8

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Diagnostic Confirmation Before Treatment (Avoiding Misdiagnosis)

• Perform wet mount with 10% KOH to visualize yeast or pseudohyphae before prescribing fluconazole—symptoms alone are nonspecific and present in only ~50% of self-diagnosed cases. 1, 5, 7
• Check vaginal pH: ≤4.5 supports candidiasis; >4.5 suggests bacterial vaginosis or trichomoniasis. 1, 5
• Obtain vaginal culture if wet mount is negative but symptoms persist, to confirm diagnosis and identify species. 1, 5

Common pitfall: Empiric treatment without confirmation leads to misdiagnosis in >50% of cases. 5

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Treatment Failure and Non-Albicans Species

• If symptoms persist beyond 5-7 days or recur within 2 months, obtain a vaginal culture to identify non-albicans species such as C. glabrata or C. krusei. 1, 5
• C. glabrata accounts for 10-20% of recurrent cases and is frequently azole-resistant. 5, 7

Alternative regimens for C. glabrata:

• First-line: Boric acid 600 mg intravaginal gelatin capsules daily for 14 days (compounded)—achieves ~70% clinical and mycologic eradication. 5, 7
• Second-line: Nystatin 100,000 units intravaginal suppositories daily for 14 days. 5, 7
• Third-line: Topical 17% flucytosine cream ± 3% amphotericin B cream daily for 14 days (requires specialist referral). 3, 5

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Drug Interactions and Safety Considerations

• Warfarin: Fluconazole potentiates anticoagulant effect, elevating INR and bleeding risk—monitor INR closely. 1, 5
• Oral hypoglycemics: Enhanced hypoglycemic effect; monitor blood glucose. 5
• Phenytoin: Increased toxicity risk. 5
• Calcineurin inhibitors (tacrolimus/cyclosporine), protease inhibitors, calcium-channel blockers: Fluconazole increases drug levels; dose adjustments may be needed. 5
• Transient transaminase elevations are rare with single-dose therapy; baseline liver tests are not required in patients without known hepatic disease. 1, 5

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Critical Pitfalls to Avoid

• Do not treat asymptomatic colonization: 10-20% of women harbor Candida without symptoms—treatment is not indicated. 1, 5
• Do not use single-dose therapy for severe or recurrent disease: Extended regimens are mandatory. 5, 9
• Do not use fluconazole in pregnancy: Only 7-day topical azole regimens are recommended; oral fluconazole is contraindicated. 5
• Do not ignore treatment failure patterns: Missing non-albicans species delays appropriate alternative therapy. 1, 5