Metronidazole Dosing for Bacterial Vaginosis in Non-Pregnant Women
For non-pregnant adult women with bacterial vaginosis, the recommended dose is metronidazole 500 mg orally twice daily for 7 days. 1
Primary Treatment Regimen
Oral metronidazole 500 mg twice daily for 7 days is the CDC-recommended first-line treatment for bacterial vaginosis in non-pregnant women, achieving cure rates of approximately 78% at follow-up. 1, 2
This regimen provides systemic therapy that treats both vaginal and potential subclinical upper genital tract infections. 2
Alternative Oral Regimen
Metronidazole 2 g orally as a single dose is an alternative option, though it has lower efficacy compared to the 7-day course and should be reserved for situations where adherence to multi-day therapy is a concern. 1
Another alternative is clindamycin 300 mg orally twice daily for 7 days, which achieves cure rates of 93.9%. 1
Topical Treatment Options
If the patient prefers or requires topical therapy:
Metronidazole gel 0.75%, one full applicator (5 g) intravaginally once daily for 5 days is equally effective to twice-daily dosing and improves compliance. 1, 3, 4
The gel formulation produces mean peak serum concentrations less than 2% of standard oral doses, minimizing systemic side effects. 1, 3
Clindamycin cream 2%, one full applicator (5 g) intravaginally at bedtime for 7 days is another topical alternative. 1
Critical Patient Counseling
Patients must avoid all alcohol consumption during metronidazole treatment and for 24 hours after completion to prevent disulfiram-like reactions. 1, 3, 5
Clindamycin cream is oil-based and will weaken latex condoms and diaphragms; patients must use alternative contraception during treatment. 1
Metronidazole gel does not affect latex barrier contraceptives. 5
Partner Management and Follow-Up
Routine treatment of male sex partners is NOT recommended, as clinical trials demonstrate that partner treatment does not affect cure rates or reduce recurrence. 1, 3, 5
Follow-up visits are unnecessary if symptoms resolve completely. 1, 5
Common Pitfall to Avoid
Do not use metronidazole vaginal gel for trichomoniasis treatment, as topical formulations are considerably less efficacious than oral preparations for this infection. 3
Patients with true metronidazole allergy should not use metronidazole gel, as systemic absorption still occurs; use clindamycin cream instead. 1, 5