Treatment of Bacterial Vaginosis
First-Line Treatment Regimens
Oral metronidazole 500 mg twice daily for 7 days is the preferred first-line treatment for bacterial vaginosis, achieving cure rates up to 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 (less than 2% of serum levels achieved with oral dosing) 4, 1
Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days 4, 1
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, tachycardia) 4, 1, 3
Clindamycin cream and ovules are oil-based and will weaken latex condoms and diaphragms—patients must use alternative contraception during treatment 4, 1, 3
Alternative Regimens (Lower Efficacy)
Use these only when compliance with 7-day regimens is a major concern:
Metronidazole 2g orally as a single dose—cure rate only 84% compared to 95% for the 7-day regimen 4, 2, 3
Tinidazole 2g once daily for 2 days OR 1g once daily for 5 days—demonstrated therapeutic cure rates of 22-32% (compared to 5% placebo) in controlled trials 5
Treatment in Pregnancy
High-Risk Pregnant Women (Prior Preterm Delivery)
Metronidazole 250 mg orally three times daily for 7 days is the recommended treatment to reduce risk of prematurity and relieve symptoms 1, 2, 3, 6
- Systemic therapy is preferable to treat possible subclinical upper tract infection 6
- Treatment may reduce risk of preterm labor, preterm birth, and postpartum endometritis 4, 3
Low-Risk Pregnant Women (No Prior Preterm Delivery)
Metronidazole 250 mg orally three times daily for 7 days for symptomatic disease only 3, 6
First Trimester Considerations
Clindamycin vaginal cream is preferred during first trimester due to historical concerns about metronidazole teratogenicity, though recent meta-analyses do not indicate teratogenicity in humans 4, 1
Patients with Metronidazole Allergy or Intolerance
Clindamycin cream 2% intravaginally OR oral clindamycin 300 mg twice daily for 7 days 1, 2
Special Clinical Situations
Before Surgical Procedures
Screen and treat all women with BV before surgical abortion or hysterectomy in addition to routine prophylaxis 4, 3
- Treatment with metronidazole reduces postabortion pelvic inflammatory disease by 10-75% 4, 3
- BV-associated bacteria have been recovered from endometria and salpinges of women with PID 4
- BV increases risk of endometritis, vaginal cuff cellulitis, and post-hysterectomy infectious complications 4, 3
HIV-Infected Patients
Patients with HIV should receive the same treatment regimens as persons without HIV 1
Breastfeeding Women
Standard CDC guidelines apply—metronidazole is compatible with breastfeeding as only small amounts are excreted in breast milk 1
Management of Sex Partners
Do NOT routinely treat male sex partners—clinical trials demonstrate no effect on cure rates, relapse, or recurrence 1, 2, 3, 6
Follow-Up
Follow-up visits are unnecessary if symptoms resolve 4, 1, 2, 3
- Advise patients to return for additional therapy if symptoms recur 4, 2, 3
- Recurrence is common—50-80% of women experience recurrence within one year 7, 8
- For pregnant high-risk women, consider follow-up evaluation at 1 month after treatment completion to confirm therapeutic success 4
Recurrent Bacterial Vaginosis
For recurrent BV, use metronidazole 500 mg twice daily for 10-14 days 7