Fluconazole Dosing for Vaginal Thrush
For uncomplicated vaginal candidiasis, take a single oral dose of fluconazole 150 mg—this achieves clinical cure in over 90% of cases and is the FDA-approved, guideline-recommended first-line treatment. 1, 2
Standard Single-Dose Regimen (Most Common Scenario)
Fluconazole 150 mg orally as a single dose is the treatment of choice for uncomplicated vaginal yeast infection, providing efficacy equivalent to multi-day topical azole therapy with superior convenience. 3, 2, 1
This regimen achieves clinical cure rates of 80–90% and mycologic eradication in 72–93% of patients at follow-up. 2, 4
Symptoms typically resolve within 5–16 days; if they persist beyond this timeframe or recur within 2 months, you require re-evaluation with repeat cultures. 2, 5
When to Use Extended Multi-Dose Regimens
Severe Acute Infection
If you have extensive vulvar erythema, edema, excoriation, or fissures, the single-dose regimen is inadequate—you need fluconazole 150 mg every 72 hours for 2–3 doses (total 450 mg over 6 days). 3, 2, 6
Alternatively, use topical azole therapy for 7–14 days instead of oral fluconazole for severe disease. 2, 5
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 remission. 3, 2, 7
Maintenance phase: Fluconazole 150 mg once weekly for 6 months—this controls symptoms in >90% of patients during treatment. 3, 2, 7
Critical caveat: After stopping the 6-month maintenance course, 40–50% of patients experience recurrence, so this is suppressive therapy rather than a cure. 2, 7
The median time to recurrence is 10.2 months with maintenance versus 4.0 months without it. 2, 7
Diagnostic Confirmation Before Treatment (Avoid Misdiagnosis)
Perform wet-mount microscopy with 10% KOH to visualize yeast or pseudohyphae before prescribing fluconazole—symptoms alone are unreliable, with self-diagnosis accurate in only 30–50% of cases. 2, 5
Measure vaginal pH: pH ≤4.5 supports candidiasis; pH >4.5 suggests bacterial vaginosis or trichomoniasis, which require completely different treatments. 2, 5
Obtain a vaginal culture if the wet mount is negative but symptoms persist, or if you have recurrent infections—this identifies non-albicans species that need alternative therapy. 2, 5
When Fluconazole Will Fail (Non-Albicans Species)
Candida glabrata accounts for 10–20% of recurrent cases and is frequently azole-resistant. 2, 8
If symptoms persist after appropriate fluconazole therapy, obtain a culture to identify non-albicans species. 2, 5
For confirmed C. glabrata: Use boric acid 600 mg intravaginal gelatin capsules daily for 14 days (compounded)—this achieves approximately 70% clinical and mycologic eradication. 2, 8
Alternative options include nystatin 100,000 U intravaginal suppositories daily for 14 days, or topical 17% flucytosine cream ± 3% amphotericin B cream daily for 14 days (requires specialist referral). 2, 8
Critical Safety Considerations and Drug Interactions
Fluconazole potentiates warfarin, increasing INR and bleeding risk—monitor INR closely if you take both medications. 2, 5
It may enhance the hypoglycemic effect of oral antidiabetic agents, increasing hypoglycemia risk. 2
Co-administration with phenytoin can increase toxicity risk; levels of calcineurin inhibitors, protease inhibitors, and calcium-channel blockers are also increased. 2, 8
Transient liver enzyme elevations are rare with single-dose therapy; baseline liver testing is not required unless you have known hepatic disease. 2
Common Pitfalls to Avoid
Do not treat asymptomatic Candida colonization—10–20% of women harbor Candida without symptoms, and treatment is not indicated. 2, 5, 8
Do not use single-dose therapy for severe or recurrent disease—these require extended regimens as outlined above. 2, 6
Do not treat empirically without diagnostic confirmation—this leads to misdiagnosis in >50% of cases. 2, 5
Do not treat sexual partners routinely—vulvovaginal candidiasis is not a sexually transmitted infection. 8