What is the treatment for bacterial vaginosis?

Treatment of Bacterial Vaginosis

The recommended first-line treatment for bacterial vaginosis is oral metronidazole 500 mg twice daily for 7 days, metronidazole gel 0.75% intravaginally once daily for 5 days, or clindamycin cream 2% intravaginally at bedtime for 7 days. 1, 2

Diagnostic Criteria

• BV diagnosis requires meeting at least 3 of 4 Amsel criteria: homogeneous white discharge, clue cells on microscopy, vaginal pH >4.5, and positive whiff test (fishy odor after adding 10% KOH) 1, 2
• Alternatively, Gram stain can be used to determine the relative concentration of bacterial morphotypes characteristic of BV 1
• BV results from replacement of normal H2O2-producing Lactobacillus species with high concentrations of anaerobic bacteria, G. vaginalis, and Mycoplasma hominis 1

Treatment Options

First-Line Treatments (Non-Pregnant Women)

• Metronidazole 500 mg orally twice daily for 7 days (95% cure rate) 1, 2
• Metronidazole gel 0.75%, one full applicator (5g) intravaginally once daily for 5 days 1, 2
• Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days 1

Alternative Regimens

• Metronidazole 2g orally in a single dose (84% cure rate) - less effective but useful when compliance is a concern 1
• Clindamycin 300 mg orally twice daily for 7 days 1
• Tinidazole has FDA approval for BV treatment, with therapeutic cure rates of 36.8% (1g daily for 5 days) and 27.4% (2g daily for 2 days) 3

Special Populations

Pregnant Women

• BV during pregnancy is associated with adverse outcomes including premature rupture of membranes, preterm labor, preterm birth, and postpartum endometritis 1
• All symptomatic pregnant women should be tested and treated 1
• Recommended treatment for pregnant women is oral metronidazole or clindamycin 1
• A follow-up evaluation one month after treatment completion is recommended to verify effectiveness 1

Before Surgical Procedures

• Treatment of BV before surgical abortion procedures is recommended as it substantially reduces post-abortion PID 1, 2
• Consider treatment before hysterectomy or other invasive gynecological procedures due to increased risk of postoperative infectious complications 1, 2

Treatment Considerations

• Patients using metronidazole should avoid alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reaction 1
• Clindamycin cream is oil-based and might weaken latex condoms and diaphragms 1
• Treatment of male sex partners has not been shown to be beneficial in preventing recurrence of BV 1, 4
• 50-80% of women experience BV recurrence within a year of completing antibiotic treatment 5, 6

Recurrent BV Management

• For recurrent BV, an extended course of metronidazole treatment (500 mg twice daily for 10-14 days) is recommended 6
• If ineffective, metronidazole vaginal gel 0.75% for 10 days, followed by twice weekly for 3-6 months, is an alternative regimen 6
• Emerging strategies for recurrent BV include biofilm disruption, probiotics, prebiotics, and pH modulation, though these require further study 5, 7

Clinical Pitfalls to Avoid

• Treating asymptomatic women unnecessarily exposes them to medication side effects without clear benefit 2
• Failing to treat before invasive gynecological procedures may increase risk of post-procedure infections 1, 2
• Not distinguishing BV from other causes of vaginitis (trichomoniasis, candidiasis) which require different treatments 1, 8
• Overlooking the high recurrence rate of BV and not counseling patients about this possibility 5, 6