Treatment of Bacterial Vaginosis
The first-line treatment for bacterial vaginosis is metronidazole 500 mg orally twice daily for 7 days, which achieves a 95% cure rate. 1
Diagnostic Confirmation Before Treatment
Diagnose BV using Amsel's criteria (requiring at least 3 of 4 findings): 1, 2
- Homogeneous white discharge coating vaginal walls
- Clue cells on microscopic examination
- Vaginal pH >4.5
- Positive whiff test (fishy odor with 10% KOH)
Alternative diagnostic method includes Gram stain with Nugent score ≥4. 1
First-Line Treatment Regimens
For symptomatic non-pregnant women, choose one of these CDC-recommended options: 1, 2
- Metronidazole 500 mg orally twice daily for 7 days (95% cure rate - preferred)
- Metronidazole gel 0.75% intravaginally once daily for 5 days
- Clindamycin cream 2% intravaginally at bedtime for 7 days
Alternative Treatment Options
If first-line therapies fail or are not tolerated: 2
- Metronidazole 2g orally as single dose (lower efficacy at 84%)
- Clindamycin 300 mg orally twice daily for 7 days
- Tinidazole 2g once daily for 2 days or 1g once daily for 5 days 3
Critical Safety Warnings
Patients taking metronidazole or tinidazole must avoid alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reaction. 1, 4, 2
Clindamycin cream is oil-based and may weaken latex condoms and diaphragms. 4, 2
Treatment in Pregnancy
All symptomatic pregnant women should be treated due to associations with preterm birth, premature rupture of membranes, and postpartum endometritis. 1
For symptomatic pregnant women, use oral metronidazole in the second trimester (13-24 weeks). 1
High-risk pregnant women (history of preterm delivery) with asymptomatic BV may benefit from evaluation and treatment. 1, 4
Average-risk pregnant women with asymptomatic BV should NOT be routinely screened or treated, as it does not improve outcomes. 4
Follow-up evaluation one month after treatment completion is recommended in pregnant women to verify cure. 4
Treatment of Asymptomatic BV
Generally, asymptomatic women do not require treatment, as the goal is to relieve symptoms. 4, 2
Exceptions where asymptomatic BV should be treated: 4
- Before surgical abortion procedures (to reduce post-abortion PID)
- Before hysterectomy or other invasive gynecological procedures
- High-risk pregnant women with history of preterm delivery
Treatment regimens for asymptomatic BV when indicated are the same as for symptomatic disease. 4
Recurrent BV Management
Recurrence occurs in 50-80% of women within 1 year after standard treatment. 1, 5
For recurrent BV, use extended therapy: 1, 5
- Metronidazole 500 mg orally twice daily for 10-14 days, OR
- Metronidazole gel 0.75% intravaginally twice weekly for 3-6 months as suppressive therapy
Probiotics containing Lactobacillus species as complementary therapy with antibiotics may improve cure rates. 2
Partner Treatment
Do not treat male sex partners routinely - multiple trials demonstrate this does not prevent recurrence or alter clinical outcomes. 1, 4, 2
Common Pitfalls to Avoid
Up to 50% of women meeting diagnostic criteria are asymptomatic, so avoid unnecessary treatment in these cases unless specific indications exist. 4, 2
Follow-up visits are unnecessary if symptoms resolve, except in pregnancy. 4
The high recurrence rate is likely due to biofilm formation protecting bacteria from antimicrobials and failure to reestablish Lactobacillus-dominated flora. 5, 6