What is the treatment for bacterial vaginosis?

Treatment of Bacterial Vaginosis

First-Line Treatment Recommendations

Oral metronidazole 500 mg twice daily for 7 days is the preferred first-line treatment for bacterial vaginosis, achieving the highest cure rate of 95%. 1, 2, 3

The following regimens are equally acceptable first-line options for non-pregnant women:

• Metronidazole gel 0.75%, one full applicator (5g) intravaginally once daily for 5 days—equally efficacious as oral therapy but with fewer systemic side effects (gastrointestinal upset, unpleasant taste) 1, 2, 3

• Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days 1, 2, 3

Alternative Regimens (Lower Efficacy)

When compliance is a major concern, consider:

• Oral metronidazole 2g as a single dose—cure rate of only 84% compared to 95% for the 7-day regimen, making this substantially less effective 1, 2, 3

• Oral clindamycin 300 mg twice daily for 7 days—use when metronidazole cannot be tolerated 1, 2

• Tinidazole 2g once daily for 2 days OR 1g once daily for 5 days—demonstrated therapeutic cure rates of 27.4% and 36.8% respectively in controlled trials 4

Critical Patient Counseling

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

• Clindamycin cream and ovules are oil-based and will weaken latex condoms and diaphragms—patients must use alternative contraception during treatment 1, 2, 3

Special Populations

Pregnancy

All symptomatic pregnant women should be tested and treated for bacterial vaginosis. 1, 2

• First trimester: Clindamycin vaginal cream is preferred due to theoretical concerns about metronidazole teratogenicity, though recent meta-analyses do not support teratogenicity in humans 5, 1

• Second and third trimesters: Metronidazole 250 mg orally three times daily for 7 days is the recommended regimen 1, 2, 6

• High-risk pregnant women (history of preterm delivery): Treatment may reduce risk of prematurity and should be considered even when asymptomatic 5, 1, 3

• Follow-up evaluation at 1 month after treatment completion should be performed in high-risk pregnant women to confirm therapeutic success 5

Metronidazole Allergy or Intolerance

• Use clindamycin cream 2% intravaginally or oral clindamycin 300 mg twice daily for 7 days 1, 2

• Never administer metronidazole vaginally to patients allergic to oral metronidazole 1

HIV Infection

• Patients with HIV should receive identical treatment regimens as HIV-negative patients 1

Clinical Context: Why Treatment Matters

Bacterial vaginosis significantly increases risk for serious complications:

• Post-abortion PID: Treatment with metronidazole reduces risk by 10-75% 5, 3

• Adverse pregnancy outcomes: Including preterm rupture of membranes, preterm labor, preterm birth, and postpartum endometritis 5

• Post-hysterectomy infectious complications: BV increases risk substantially 5, 3

• Before surgical abortion or hysterectomy: Screen and treat all women with BV in addition to routine prophylaxis 5, 3

Follow-Up and Partner Management

• Follow-up visits are unnecessary if symptoms resolve—patients should simply return if symptoms recur 1, 2, 3

• Do not treat male sex partners routinely—clinical trials demonstrate no effect on cure rates, relapse, or recurrence 5, 3

• Recurrence is common (50-80% within one year), likely due to biofilm persistence and failure of lactobacilli recolonization 7, 8

Management of Recurrent BV

For recurrent disease after initial treatment failure:

• Extended metronidazole 500 mg orally twice daily for 10-14 days 8

• If still ineffective: Metronidazole gel 0.75% for 10 days, then twice weekly for 3-6 months 8

• Alternative regimens (oral clindamycin, tinidazole) may be used, though evidence is limited 8