Treatment of Recurrent Bacterial Vaginosis
For recurrent bacterial vaginosis, treat with metronidazole 500 mg orally twice daily for 10-14 days, followed by suppressive therapy with metronidazole gel 0.75% twice weekly for 3-6 months to reduce recurrence rates from approximately 60% to 25%. 1, 2, 3
Initial Treatment of Recurrent Episodes
When a patient presents with recurrent BV (defined as recurrence within 12 months of initial treatment), the approach differs from first-episode management:
Extended oral metronidazole therapy (500 mg twice daily for 10-14 days) is the recommended first-line treatment for recurrent BV, providing higher cure rates than standard 7-day regimens 2, 4
If the extended oral regimen fails, switch to metronidazole gel 0.75% intravaginally once daily for 10 days 2
Alternative options include tinidazole 2g once daily for 2 days or 1g once daily for 5 days, which demonstrated therapeutic cure rates of 27.4% and 36.8% respectively in FDA trials 5
Suppressive Maintenance Therapy
The critical difference in managing recurrent BV is implementing long-term suppressive therapy after achieving initial cure:
After completing the initial treatment course, use metronidazole gel 0.75% twice weekly for 3-6 months 1, 2
This suppressive regimen reduces recurrence rates significantly: 25.5% with suppressive therapy versus 59.1% with placebo during the treatment period 3
By 28 weeks of follow-up, 51% of women on suppressive therapy remained cured compared to only 25% without suppression 3
Important Clinical Considerations
Recurrence is extremely common—50-80% of women experience BV recurrence within one year of standard antibiotic treatment 6, 2, 4. This high recurrence rate occurs because:
- Biofilm formation on vaginal mucosa protects BV-causing bacteria from antimicrobial therapy 2, 4
- Beneficial Lactobacillus species (particularly L. crispatus) fail to recolonize the vagina after antibiotic treatment 6
- Residual infection may persist despite apparent clinical cure 2
Common Pitfalls to Avoid
Do not treat sexual partners routinely—multiple trials demonstrate that partner treatment does not influence recurrence rates or treatment response 7, 1, 8
Do not use standard 7-day regimens for recurrent disease—these have unacceptably high failure rates in the recurrent setting 2
Warn patients about increased risk of secondary vaginal candidiasis during suppressive metronidazole therapy, which occurs significantly more often than with placebo 3
Counsel patients to avoid alcohol during metronidazole treatment and for 24 hours afterward due to disulfiram-like reactions 7, 1, 9
Special Populations
Pregnancy
- Treat all symptomatic pregnant women with metronidazole 250 mg orally three times daily for 7 days after the first trimester 7, 9, 10
- Use clindamycin vaginal cream during the first trimester when metronidazole is contraindicated 7, 9
Metronidazole Allergy or Intolerance
- Use clindamycin cream 2% intravaginally at bedtime for 7 days or oral clindamycin 300 mg twice daily for 7 days 7, 1, 9
- Never administer metronidazole vaginally to patients with true oral metronidazole allergy 7, 1, 9