Treatment of Bacterial Vaginosis
The recommended first-line treatment for bacterial vaginosis is oral metronidazole 500 mg twice daily for 7 days, which has the highest efficacy with a 95% cure rate. 1
First-Line Treatment Options
- Oral metronidazole 500 mg twice daily for 7 days is the preferred treatment regimen with the highest efficacy 2, 1
- Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days is an equally effective first-line option 2, 1
- Metronidazole gel 0.75%, one full applicator (5g) intravaginally twice daily for 5 days is another effective option with fewer systemic side effects 2, 1, 3
Alternative Treatment Options
- Metronidazole 2g orally in a single dose is an alternative with lower efficacy (84% cure rate) but may be useful when compliance is a concern 2, 1
- Clindamycin 300 mg orally twice daily for 7 days is an alternative when metronidazole cannot be used 2, 1
- Tinidazole has shown efficacy as either 2g once daily for 2 days or 1g once daily for 5 days 4
Treatment Considerations
Side Effects and Precautions
- Patients using metronidazole should avoid alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reaction 2, 1
- Clindamycin cream is oil-based and might weaken latex condoms and diaphragms 2, 1
- Oral metronidazole may cause gastrointestinal upset and unpleasant taste; intravaginal preparations have fewer systemic side effects 2, 3
- In a randomized controlled trial, intravaginal metronidazole showed similar efficacy to oral administration (92.5% vs 89.9%) but with significantly fewer side effects such as nausea (10.2% vs 30.4%) and abdominal pain (16.8% vs 31.9%) 3
Allergy or Intolerance to Metronidazole
- Clindamycin cream is preferred in case of allergy or intolerance to metronidazole 2, 1
- Patients allergic to oral metronidazole should not be administered metronidazole vaginally 2, 1
Special Populations
Pregnancy
- During first trimester: Clindamycin vaginal cream is preferred due to contraindication of metronidazole 2, 1
- During second and third trimesters: Metronidazole 250 mg orally three times daily for 7 days is recommended 1, 5
- Treatment of BV in high-risk pregnant women (history of preterm delivery) may reduce risk of prematurity 1, 5
Before Invasive Procedures
- Treatment of BV before surgical abortion procedures is recommended as it has been shown to substantially reduce post-abortion PID 2, 1
- Consider treatment before other invasive procedures such as hysterectomy, endometrial biopsy, or IUD placement 2, 1
Follow-Up and Recurrence Management
- Follow-up visits are unnecessary if symptoms resolve 2, 1
- Recurrence of BV is common; the alternative treatment regimens can be used for treatment of recurrent disease 2, 6
- No long-term maintenance regimen with any therapeutic agent is currently recommended 2
Management of Sex Partners
- Routine treatment of male sex partners is not recommended as it has not been shown to influence a woman's response to therapy or reduce recurrence rates 2, 1
Common Pitfalls
- Mistaking cytolytic vaginosis (which has an acidic pH <4.0) for bacterial vaginosis (pH >4.5); treating cytolytic vaginosis with antibiotics would worsen the condition 7
- Using the single-dose metronidazole regimen as first-line therapy despite its lower efficacy compared to the 7-day regimen 1, 8
- Failing to advise patients about alcohol restriction during metronidazole treatment 2
- Not considering treatment before invasive gynecological procedures, which could lead to increased risk of post-procedure infections 2, 1