Treatment for Bacterial Vaginosis
The first-line treatment for bacterial vaginosis is oral metronidazole 500 mg twice daily for 7 days, which has a 95% cure rate and is recommended by the CDC. 1
First-Line Treatment Options
The CDC recommends several equally effective first-line treatment regimens:
- Oral metronidazole: 500 mg twice daily for 7 days
- Metronidazole gel: 0.75%, one full applicator (5g) intravaginally once daily for 5 days
- Clindamycin cream: 2%, one full applicator (5g) intravaginally at bedtime for 7 days 1
Efficacy Comparison
- Oral metronidazole (7-day regimen): 95% cure rate
- Single-dose metronidazole (2g): 84% cure rate 1
Alternative Treatment
- Tinidazole: FDA-approved for bacterial vaginosis in adult women
- 2g once daily for 2 days OR
- 1g once daily for 5 days 2
Treatment Considerations
During Treatment
- Patients should abstain from sexual intercourse until completing the full treatment course 1
- Patients using metronidazole should avoid alcohol during treatment and for 24 hours afterward to prevent disulfiram-like reactions 1
Side Effects
- Metronidazole may cause:
- Gastrointestinal disturbances
- Metallic taste
- Disulfiram-like reaction with alcohol
- Potential peripheral neuropathy with prolonged use 1
Partner Treatment
- Unlike some STIs, routine treatment of male sex partners is not recommended for bacterial vaginosis 1
Special Populations
Pregnant Women
- First trimester: Clindamycin cream 2% applied intravaginally at bedtime for 7 days is the preferred treatment 1
- After first trimester: Metronidazole may be safely used 1
- Alternative during pregnancy: Amoxicillin-clavulanic acid 1
- Treatment is recommended during pregnancy due to association with:
- Premature rupture of membranes
- Preterm labor and birth
- Postpartum endometritis
- Chorioamnionitis 1
Follow-up and Recurrence
Follow-up
- Non-pregnant women: Follow-up visits not necessary if symptoms resolve 1
- Pregnant women: Follow-up evaluation 1 month after treatment completion 1
Recurrent BV
- BV recurrence is common (50-80% of women experience recurrence within a year) 1
- For recurrence, use a different treatment regimen than the initial one 1
- Extended treatment options for recurrent BV:
- Metronidazole 500 mg twice daily for 10-14 days
- If ineffective, metronidazole vaginal gel 0.75% for 10 days, followed by twice weekly for 3-6 months 3
Diagnosis Confirmation
Bacterial vaginosis diagnosis requires confirming at least three of the following clinical criteria (Amsel's criteria):
- Homogeneous vaginal discharge
- Presence of clue cells on microscopic examination
- Vaginal fluid pH greater than 4.5
- Positive whiff test (fishy odor when vaginal discharge is mixed with 10% KOH) 1, 2
Common Pitfalls to Avoid
- Incomplete treatment: Ensure patients complete the full course of treatment even if symptoms resolve early
- Alcohol consumption: Warn patients about avoiding alcohol during and 24 hours after metronidazole treatment
- Misdiagnosis: Rule out other common causes of vulvovaginitis such as Trichomonas vaginalis, Chlamydia trachomatis, Neisseria gonorrhoeae, Candida albicans, and Herpes simplex virus 2
- Inadequate follow-up: Especially important for pregnant women to confirm cure