What is the treatment approach for the male partner of a woman with bacterial vaginosis (BV)?

Male Partner Treatment for Bacterial Vaginosis

Direct Recommendation

Treat male partners of women with bacterial vaginosis with combination therapy: metronidazole 400 mg orally twice daily for 7 days PLUS 2% clindamycin cream applied topically to penile skin (including under the foreskin if uncircumcised) twice daily for 7 days. 1

This recommendation represents a paradigm shift from historical practice, based on the most recent and highest quality evidence demonstrating superior outcomes for women when their male partners receive concurrent treatment.

Evidence Supporting Partner Treatment

Landmark 2025 Trial Results

• A randomized controlled trial published in 2025 demonstrated that concurrent male partner treatment reduced bacterial vaginosis recurrence from 63% to 35% within 12 weeks (absolute risk reduction of 28%, P<0.001) 1
• The trial was stopped early by the data and safety monitoring board because treatment of women alone was clearly inferior to treating both partners 1
• This represents a recurrence rate of 1.6 per person-year with partner treatment versus 4.2 per person-year with standard care alone 1

Microbiological Rationale

• Concurrent partner treatment significantly reduces BV-associated bacteria at all three anatomical sites: vagina, penile skin, and male urethra 2
• The suppression of BV-associated bacteria was sustained in 81% of women over 12 weeks despite some reemergence in male partners 2
• Male partners carry BV-associated organisms that can reinfect women, contributing to the unacceptably high recurrence rates seen with female-only treatment 3, 2

Treatment Protocol

For Male Partners

• Oral metronidazole 400 mg twice daily for 7 days 1
• PLUS 2% clindamycin cream applied topically to the glans penis and upper shaft (under the foreskin if uncircumcised) twice daily for 7 days 1
• The combination of oral and topical therapy is essential—topical therapy alone is insufficient 2, 1

For Female Partners

• Women should receive standard first-line treatment: metronidazole 500 mg orally twice daily for 7 days 4
• Alternative: clindamycin 2% vaginal cream if metronidazole is contraindicated 4

Critical Patient Instructions

• Both partners must avoid all alcohol during metronidazole treatment and for 24 hours after completion to prevent disulfiram-like reactions 4
• Refrain from unprotected intercourse for at least 14 days to allow treatment to take effect 5
• Adherence is crucial—women whose partners adhered to treatment were significantly less likely to experience treatment failure 5

Safety and Tolerability

Common Adverse Events in Men

• Nausea, headache, and metallic taste are the most common side effects 1
• Gastrointestinal symptoms occur more frequently with active treatment compared to placebo (RR 2.55) 6
• Despite these side effects, men in clinical trials demonstrated good adherence and found the treatment acceptable 2

Reconciling Contradictory Historical Guidelines

Why Older Guidelines Differ

• CDC guidelines from 1993 and 1998 stated that "treatment of sex partners is not recommended" because early trials showed no benefit 4
• These older trials used oral metronidazole alone for male partners, not the combination of oral plus topical therapy 6
• A 2016 Cochrane review confirmed that oral antibiotics alone for male partners do not reduce recurrence 6

The Critical Difference

• The 2025 trial used combination oral PLUS topical therapy, which targets BV-associated bacteria on penile skin where they colonize 1
• This dual approach addresses both urethral and cutaneous reservoirs of BV-associated organisms 2
• Previous failures with oral-only treatment explain why historical guidelines recommended against partner treatment 6

Common Pitfalls to Avoid

• Do not prescribe oral antibiotics alone for male partners—this approach has been proven ineffective 6
• Do not skip the topical clindamycin component—penile skin colonization is a key reservoir for reinfection 2
• Do not allow alcohol consumption during treatment—this can cause severe disulfiram-like reactions 4
• Ensure both partners complete the full 7-day course—partial adherence significantly reduces efficacy 5

Follow-Up Considerations

• No routine follow-up is needed for asymptomatic male partners 4
• Women should return if symptoms persist or recur after treatment 4
• For pregnant women with BV, follow-up evaluation one month after treatment completion is recommended to verify cure 4