What is the first line treatment for bacterial vaginosis?

From the Guidelines

The first-line treatment for bacterial vaginosis is oral metronidazole 500 mg twice daily for 7 days. This recommendation is based on the guidelines provided by the Centers for Disease Control and Prevention, as outlined in the 2002 sexually transmitted diseases treatment guidelines 1. Alternative regimens include metronidazole 0.75% vaginal gel applied once daily for 5 days, or clindamycin 2% vaginal cream applied at bedtime for 7 days.

Key Considerations

• Patients should be advised to avoid consuming alcohol during treatment with metronidazole and for 24 hours thereafter, due to potential disulfiram-like reactions.
• Clindamycin cream and ovules are oil-based and might weaken latex condoms and diaphragms.
• Treatment is important even for asymptomatic cases in pregnant women due to risks of preterm birth.
• Sexual partners typically don't require treatment, but recurrence is common (about 30% within 3 months) 1.

Mechanism and Rationale

Bacterial vaginosis results from an imbalance in vaginal flora with overgrowth of anaerobic bacteria and reduction of protective lactobacilli, leading to the characteristic fishy odor, thin discharge, and elevated vaginal pH. Metronidazole works by directly targeting these anaerobic organisms to restore normal vaginal flora.

Follow-Up and Recurrence

Follow-up visits are unnecessary if symptoms resolve, but recurrence is not unusual and patients should return for additional treatment if symptoms recur 1.

From the FDA Drug Label

In patients with all four Amsel's criteria and with a baseline Nugent score ≥4, tinidazole oral tablets given as either 2 g once daily for 2 days or 1 g once daily for 5 days demonstrated superior efficacy over placebo tablets as measured by therapeutic cure, clinical cure, and a microbiologic cure. The first line treatment for bacterial vaginosis is tinidazole, which can be administered as either:

• 2 g once daily for 2 days
• 1 g once daily for 5 days 2 2 Key points:
• Tinidazole has been shown to be effective in treating bacterial vaginosis
• The treatment regimen can be either 2 g for 2 days or 1 g for 5 days
• The diagnosis of bacterial vaginosis should be based on Amsel's criteria and a Nugent score of ≥4 2

From the Research

First Line Treatment for Bacterial Vaginosis

The first line treatment for bacterial vaginosis includes:

• Oral metronidazole (500 mg twice daily for 7 days) 3, 4
• Single-dose metronidazole (2 g orally) 3, 5
• 2% clindamycin vaginal cream (once daily for 7 days) 3, 4, 6
• 0.75% metronidazole vaginal gel (twice daily for 5 days) 3, 4, 6
• Oral clindamycin (300 mg twice daily for 7 days) 3, 4, 5

Treatment Considerations

Treatment considerations include:

• For nonpregnant women, metronidazole, clindamycin vaginal cream, or metronidazole vaginal gel are recommended 4
• For pregnant high-risk women, systemic therapy with metronidazole (250 mg orally three times a day for 7 days) is recommended 4
• For pregnant low-risk women with symptomatic disease, metronidazole (250 mg orally three times a day for 7 days) is recommended 4
• Treatment of bacterial vaginosis during pregnancy should focus on the elimination of symptoms 3

Alternative Treatments

Alternative treatments include:

• Oral tinidazole, which has been shown to be equivalent to oral metronidazole, intravaginal clindamycin cream, and intravaginal metronidazole tablets in efficacy, with a more favorable side effect profile 7
• Probiotics (Lactobacillus acidophilus) may be considered as an alternative treatment, but additional research is needed 5