What is the treatment for bacterial vaginosis (BV)?

Treatment of Bacterial Vaginosis

For non-pregnant women with bacterial vaginosis, treat with metronidazole 500 mg orally twice daily for 7 days, which demonstrates superior efficacy with 95% cure rates compared to alternative regimens. 1

First-Line Treatment Options for Non-Pregnant Women

The CDC establishes three equally acceptable first-line regimens: 1, 2

• Metronidazole 500 mg orally twice daily for 7 days - This is the preferred systemic option with the highest cure rate (95%) 1
• Metronidazole gel 0.75%, one full applicator (5g) intravaginally once daily for 5 days - Equally effective topical alternative with minimal systemic absorption (<2% of oral bioavailability) 3, 1
• Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days - Another first-line topical option with approximately 82% cure rate at 4 weeks 3, 1

Alternative Regimens (Lower Efficacy)

Use these only when compliance is a major concern: 1, 2

• Metronidazole 2g orally as a single dose - Has only 84% cure rate versus 95% for the 7-day regimen, making it substantially less effective 1
• Clindamycin 300 mg orally twice daily for 7 days - Alternative systemic option 3, 1
• Tinidazole 2g once daily for 2 days OR 1g once daily for 5 days - FDA-approved with therapeutic cure rates of 22-32% above placebo 4

Critical Patient Counseling Points

Patients must avoid all alcohol during metronidazole treatment and for 24 hours after completion to prevent disulfiram-like reactions (flushing, nausea, vomiting, tachycardia). 3, 1, 2, 5

Oil-based clindamycin formulations (cream and ovules) weaken latex condoms and diaphragms - patients must use alternative contraception during treatment. 3, 1, 2, 5

For patients with documented metronidazole allergy, they should not use metronidazole vaginally either, as systemic absorption still occurs; clindamycin cream is the preferred alternative. 2, 5

Treatment During Pregnancy

The approach differs based on risk stratification:

For high-risk pregnant women (prior preterm birth):

• Metronidazole 250 mg orally three times daily for 7 days - This systemic therapy addresses possible subclinical upper tract infection 1, 2, 6
• Treatment aims to prevent adverse pregnancy outcomes (preterm delivery, low birth weight) in addition to symptom relief 2, 6

For low-risk pregnant women with symptomatic disease:

• Metronidazole 250 mg orally three times daily for 7 days - Primary goal is symptom relief 1, 2, 6

During first trimester specifically:

• Clindamycin vaginal cream is preferred due to theoretical concerns about metronidazole, though recent meta-analyses show no teratogenicity in humans 3, 2

Alternative pregnancy regimens include metronidazole 2g single dose or clindamycin 300 mg orally twice daily for 7 days. 2

Special Clinical Situations

Before surgical procedures:

• Screen and treat all women (symptomatic or asymptomatic) before surgical abortion, as treatment reduces postabortion PID by 10-75% 3, 5
• Consider screening before hysterectomy, endometrial biopsy, IUD placement, and uterine curettage due to increased risk of postoperative infectious complications 3, 2

For metronidazole-resistant or recurrent BV:

• Use clindamycin 300 mg orally twice daily for 7 days or clindamycin cream 2% intravaginally for 7 days 5
• Extended metronidazole regimen (500 mg twice daily for 10-14 days) followed by maintenance therapy with metronidazole gel twice weekly for 3-6 months may be considered 7
• Do not repeat the same failed therapy 5

Management of Sex Partners

Do not routinely treat male sex partners - multiple clinical trials demonstrate no effect on cure rates, relapse rates, or recurrence in women. 3, 1, 2, 5, 6

Follow-Up

Follow-up visits are unnecessary if symptoms resolve. 3, 1, 2, 5

For high-risk pregnant women, consider follow-up evaluation at 1 month after treatment completion to confirm therapeutic success. 3

Common Pitfalls to Avoid

• Do not use the single-dose metronidazole 2g regimen as first-line therapy - its 84% cure rate is significantly inferior to the 95% rate of the 7-day regimen 1
• Do not assume topical therapy is less effective - metronidazole gel and clindamycin cream have comparable efficacy to oral metronidazole (75-82% cure rates) 3
• Recurrence occurs in 50-80% of women within one year, often due to biofilm persistence rather than treatment failure or reinfection 8, 9, 7
• BV increases risk for HIV acquisition, other STIs, PID, and adverse pregnancy outcomes - treatment has implications beyond symptom relief 8, 9