What is the treatment for bacterial vaginosis (BV)?

Treatment of Bacterial Vaginosis

Metronidazole 500 mg orally twice daily for 7 days is the first-line treatment for bacterial vaginosis in non-pregnant women, with several equally effective alternative regimens available including vaginal options. 1

Diagnosis Confirmation

Before initiating treatment, confirm BV diagnosis using Amsel's criteria (3 of 4 required):

• Homogeneous, white discharge adhering to vaginal walls
• Presence of clue cells on microscopy
• Vaginal fluid pH > 4.5
• Positive whiff test (fishy odor with 10% KOH) 1

Treatment Options for Non-Pregnant Women

First-Line Options (equally effective):

• Metronidazole 500 mg orally twice daily for 7 days
• Metronidazole gel 0.75%, one applicator (5g) intravaginally once daily for 5 days
• Clindamycin cream 2%, one applicator (5g) intravaginally at bedtime for 7 days
• Clindamycin 300 mg orally twice daily for 7 days
• Clindamycin ovules 100g intravaginally at bedtime for 3 days 1

Alternative Regimen:

• Metronidazole 2g orally in a single dose (note: lower efficacy than 7-day regimen) 1
• Tinidazole 2g once daily for 2 days or 1g once daily for 5 days (shown to be superior to placebo) 2

Treatment for Pregnant Women

• Metronidazole 250 mg orally three times daily for 7 days (preferred to minimize fetal exposure)
• Alternative: Metronidazole 2g orally in a single dose 1

Important Precautions

• Alcohol warning: Patients must avoid alcohol during metronidazole treatment and for 24 hours afterward to prevent disulfiram-like reactions 1
• Latex warning: Clindamycin cream and ovules may weaken latex condoms and diaphragms 1
• Common side effects of oral metronidazole include gastrointestinal disturbance and unpleasant taste 1
• Intravaginal metronidazole results in significantly lower systemic absorption (mean peak serum concentrations <2% of standard oral doses) 1

Special Considerations

Pregnancy

• Test and treat all symptomatic pregnant women to prevent adverse pregnancy outcomes
• For high-risk pregnant women (history of preterm birth), screen and treat in early second trimester
• Follow-up evaluation 1 month after treatment completion is recommended for high-risk pregnant women 1

Recurrent BV

• Recurrence is common (50-80% of women experience recurrence within a year) 1, 3
• For recurrent BV, recommended treatment is extended course of metronidazole (500 mg twice daily for 10-14 days) 4
• Alternative for recurrent BV: metronidazole vaginal gel 0.75% for 10 days, followed by twice weekly for 3-6 months 4

Common Pitfalls to Avoid

1. Using single-dose regimen as first-line therapy - The 7-day regimen has higher efficacy 1
2. Failing to warn patients about alcohol interaction with metronidazole - This can cause severe reactions 1
3. Treating male sex partners - Not recommended as clinical trials show no improvement in outcomes or prevention of recurrence 1, 5
4. Not considering biofilm presence in treatment failures - High G. vaginalis abundance may indicate biofilm presence, which can reduce treatment efficacy 6
5. Overlooking pathobionts - High concentrations of pathobionts are associated with increased likelihood of treatment failure 6

Follow-up

• Routine follow-up is unnecessary if symptoms resolve (except in high-risk pregnant women) 1
• If symptoms persist, consider alternative diagnosis or treatment regimen