Fluconazole Dosing for Vaginal Yeast Infection
For an uncomplicated vaginal yeast infection, take a single oral dose of fluconazole 150 mg—this is the standard treatment recommended by the CDC, IDSA, and FDA, achieving over 90% cure rates. 1, 2
Standard Dosing for Uncomplicated Infection
- Single dose: fluconazole 150 mg orally, taken once 1, 2
- This regimen is equivalent in efficacy to multi-day topical azole therapy but offers superior convenience and patient preference 1, 3
- Clinical cure rates exceed 90%, with mycological eradication in 72-93% of patients at short-term follow-up 1, 4, 5
- Symptom relief typically occurs within 5-7 days, though therapeutic vaginal concentrations are sustained for sufficient duration after the single dose 4, 5
When to Use Multi-Dose Regimens
For severe acute vulvovaginal candidiasis (extensive vulvar erythema, edema, excoriation, or fissures):
- Fluconazole 150 mg every 72 hours for 2-3 total doses (450 mg total over 6 days) 1
For 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 1
- Maintenance phase: fluconazole 150 mg once weekly for 6 months 1
- This maintenance regimen controls symptoms in >90% of patients, though 40-50% may experience recurrence after stopping 1
Critical Diagnostic Confirmation Before Treatment
Before prescribing fluconazole, confirm the diagnosis to avoid treating non-fungal conditions:
- Wet mount with 10% KOH to visualize yeast or pseudohyphae 1, 6
- Vaginal pH ≤4.5 (higher pH suggests bacterial vaginosis or trichomoniasis) 1, 6
- Vaginal culture if wet mount is negative but symptoms persist 1, 6
- Symptoms alone (pruritus, discharge, dysuria) are nonspecific and present in only ~50% of patients who self-diagnose yeast infections 1
Treatment Failure and Non-Albicans Species
If symptoms persist beyond 5-7 days or recur within 2 months:
- Obtain vaginal culture to identify non-albicans species, particularly C. glabrata or C. krusei 1, 6
- C. glabrata is often azole-resistant and requires alternative therapy 1
For confirmed C. glabrata vulvovaginitis:
- Boric acid 600 mg intravaginal gelatin capsules daily for 14 days (must be compounded by pharmacist) 1
- Alternative: nystatin 100,000 units intravaginal suppositories daily for 14 days 1
- Second alternative: topical 17% flucytosine cream ± 3% amphotericin B cream daily for 14 days 1
Important Drug Interactions and Safety
- Warfarin: fluconazole potentiates anticoagulation, increasing INR and bleeding risk—monitor INR closely 6
- Oral hypoglycemics: risk of hypoglycemia 6
- Phenytoin: risk of toxicity 6
- Calcineurin inhibitors (tacrolimus, cyclosporine), protease inhibitors, calcium-channel blockers: increased drug levels 6
- Transient transaminase elevations can occur but are rare with single-dose therapy; baseline liver tests are not required in patients without known hepatic disease 6
Common Pitfalls to Avoid
- Treating asymptomatic colonization: 10-20% of women harbor Candida without symptoms—treatment is not indicated 6
- Empiric treatment without diagnostic confirmation: leads to misdiagnosis in >50% of cases 1
- Using single-dose therapy for complicated infections: severe or recurrent disease requires extended regimens 1
- Ignoring treatment failure patterns: persistent symptoms suggest non-albicans species requiring alternative agents 1, 6