What is the recommended treatment for recurrent bacterial vaginosis (BV) in a 45-year-old?

Treatment of Recurrent Bacterial Vaginosis in a 45-Year-Old

For recurrent BV, treat with an extended course of metronidazole 500 mg orally twice daily for 10-14 days, and if this fails, switch to metronidazole vaginal gel 0.75% for 10 days followed by twice-weekly maintenance therapy for 3-6 months. 1, 2

Initial Extended Treatment Approach

• Start with metronidazole 500 mg orally twice daily for 10-14 days (not the standard 7-day course used for initial BV) 2
• This extended duration addresses the biofilm formation that protects BV-causing bacteria from standard antimicrobial therapy and contributes to the high recurrence rates of 50-80% within one year 1, 2
• Counsel the patient to avoid all alcohol during treatment and for 24 hours after completion to prevent disulfiram-like reactions 1, 3

Second-Line Suppressive Therapy

If the extended oral course fails:

• Switch to metronidazole vaginal gel 0.75% applied intravaginally for 10 consecutive days 2
• Follow this with maintenance suppressive therapy: metronidazole vaginal gel 0.75% twice weekly for 3-6 months 2
• This suppressive regimen helps prevent recolonization by pathogenic bacteria and allows time for beneficial Lactobacillus species to potentially re-establish 4

Partner Treatment Consideration

• In cases of truly recurrent BV, consider treating the male partner with metronidazole 400 mg orally twice daily for 7 days plus clindamycin 2% cream applied to penile skin twice daily for 7 days 3
• While older CDC guidance stated partner treatment doesn't prevent recurrence, newer 2025 evidence suggests it may be beneficial in recurrent cases 1, 3
• Both partners must avoid alcohol during metronidazole treatment and refrain from unprotected intercourse for at least 14 days 3

Adjunctive Strategies

• Consider probiotics containing Lactobacillus crispatus as complementary therapy with antibiotics, as meta-analyses show they significantly improve cure rates 5, 6
• Standard probiotics are not recommended for prevention, but L. crispatus-specific vaginal products show promise for recurrent BV 6

Alternative Treatment if Standard Regimens Fail

• If extended metronidazole courses and suppressive therapy are unsuccessful, vaginal boric acid is the cheapest and easiest alternative option 6
• Clindamycin-based regimens can be considered, particularly if metronidazole resistance is suspected 2

Critical Pitfalls to Avoid

• Do not use the standard 7-day metronidazole course for recurrent BV—this is only for initial episodes and leads to high recurrence rates 1, 2
• Do not culture for Gardnerella vaginalis, as it can be isolated from 50% of normal women and lacks diagnostic specificity 1
• Recognize that the goal is symptom relief, not eradication of all colonizing bacteria 1
• Do not assume treatment failure means resistance—poor adherence and biofilm persistence are more common causes 2, 4

Follow-Up Protocol

• No routine follow-up is necessary if symptoms resolve 1
• Instruct the patient to return only if symptoms persist after completing treatment or recur 1
• At follow-up visits for persistent symptoms, reconsider the diagnosis and evaluate for alternative conditions such as desquamative inflammatory vaginitis, vulvovaginal candidiasis, or genitourinary syndrome of menopause 6