Treatment of Bacterial Vaginosis: Metronidazole Alone, Not with Fluconazole
No, you should NOT give both metronidazole and Diflucan (fluconazole) together for bacterial vaginosis—treat BV with metronidazole alone, as fluconazole is an antifungal for yeast infections, not bacteria. 1
Understanding the Fundamental Error
BV is caused by an overgrowth of anaerobic bacteria (primarily Gardnerella vaginalis and other anaerobes), not yeast. 1 Fluconazole treats Candida species (yeast infections), which are completely different organisms. 2 Adding fluconazole to BV treatment provides no benefit and exposes patients to unnecessary medication risks and costs. 1
Recommended First-Line Treatment for BV
Metronidazole 500 mg orally twice daily for 7 days is the gold standard treatment, achieving 84-95% cure rates. 1, 3
Alternative Regimens (if oral metronidazole is not suitable):
- Metronidazole gel 0.75% (one full applicator intravaginally once daily for 5 days) with 75% cure rate 1, 3
- Clindamycin cream 2% (one full applicator intravaginally at bedtime for 7 days) with 82% cure rate 1, 3
- Metronidazole 2g orally as a single dose (lower efficacy at 84%, but useful for adherence concerns) 1
Critical Patient Instructions
- Avoid all alcohol during metronidazole treatment and for 24 hours after completion to prevent disulfiram-like reactions (flushing, nausea, vomiting, tachycardia). 1, 3
- Clindamycin cream is oil-based and weakens latex condoms and diaphragms. 1
When Fluconazole IS Appropriate
Fluconazole should only be prescribed if the patient has concurrent vulvovaginal candidiasis (yeast infection), which presents differently from BV:
- BV characteristics: pH >4.5, thin homogeneous white discharge, fishy odor, clue cells on microscopy 1, 4
- Candidiasis characteristics: pH ≤4.5, thick white "cottage cheese" discharge, vulvar itching/burning, pseudohyphae on microscopy 4
If both conditions are present simultaneously (which can occur), treat both separately: metronidazole for BV AND fluconazole for candidiasis. 4
Common Clinical Pitfall
Do not reflexively add antifungals "just in case" after antibiotic treatment. While antibiotics can predispose to yeast overgrowth, this is not universal, and prophylactic fluconazole is not recommended by CDC guidelines. 1 Only treat yeast infections when clinically diagnosed.
Partner Management
Do not routinely treat male partners for standard BV cases, as multiple randomized trials show this does not affect cure rates or recurrence. 1, 3 The exception is recurrent BV, where some evidence suggests partner treatment with metronidazole 400mg twice daily for 7 days plus topical clindamycin may reduce recurrence rates. 4
Recurrent BV Management
If symptoms recur (50-80% of women experience recurrence within one year), consider: 2, 5