Treatment of Gardnerella Vaginalis Infection
The recommended first-line treatment for Gardnerella vaginalis infection (bacterial vaginosis) is oral metronidazole 500 mg twice daily for 7 days, which has a cure rate of approximately 95%. 1
First-Line Treatment Options
- Oral metronidazole 500 mg twice daily for 7 days is the preferred treatment with the highest efficacy 2, 1
- Metronidazole gel 0.75%, one full applicator (5g) intravaginally twice daily for 5 days is equally effective with fewer systemic side effects 2, 1
- Clindamycin cream 2%, one full applicator (5g) intravaginally at bedtime for 7 days is another effective first-line option 2, 1
Alternative Treatment Options
- Oral metronidazole 2g as a single dose (84% cure rate) is less effective than the 7-day regimen but may be useful when compliance is a concern 2, 1
- Oral clindamycin 300 mg twice daily for 7 days when metronidazole cannot be used 2, 1
- Tinidazole is FDA-approved for bacterial vaginosis and can be administered as either 2g once daily for 2 days or 1g once daily for 5 days 3
Treatment Considerations
Side Effects and Precautions
- Patients using metronidazole should avoid alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reaction 2, 1
- Clindamycin cream is oil-based and may weaken latex condoms and diaphragms 2, 1
- Metronidazole may cause gastrointestinal upset; intravaginal preparations have fewer systemic side effects 1, 4
Allergy or Intolerance to Metronidazole
- Clindamycin cream or oral clindamycin is preferred for patients with allergy or intolerance to metronidazole 2, 1
- Patients allergic to oral metronidazole should not be administered metronidazole vaginally 1
Special Populations
Pregnancy
- During first trimester: Clindamycin vaginal cream is preferred due to contraindication of metronidazole 2, 1
- During second and third trimesters: Oral metronidazole can be used 2, 1
- Treatment of BV in high-risk pregnant women (history of preterm delivery) may reduce risk of prematurity 2
HIV Infection
- Patients with HIV and Gardnerella vaginalis infection should receive the same treatment as persons without HIV 2, 1
Follow-Up and Management
- Follow-up visits are unnecessary if symptoms resolve 2, 1
- If treatment failure occurs with either regimen, the patient should be re-treated with metronidazole 500 mg twice daily for 7 days 2
- For persistent treatment failures, consider metronidazole 2g once daily for 3-5 days 2
Management of Sex Partners
- Routine treatment of male sex partners is not recommended as it has not been shown to influence a woman's response to therapy or reduce recurrence rates 2, 1
Special Clinical Situations
- Before surgical abortion or other invasive gynecological procedures, treatment of BV (symptomatic or asymptomatic) is recommended to reduce risk of post-procedure infections 2, 1
- Treatment of BV with metronidazole has been shown to substantially reduce post-abortion PID 2, 1
Antimicrobial Sensitivity Patterns
- While G. vaginalis may show in vitro sensitivity to various antibiotics including ciprofloxacin, cefuroxime, and erythromycin, metronidazole remains the first-line drug due to its effectiveness against both G. vaginalis and associated anaerobes 5
- Comparative studies have shown that metronidazole is more effective than ampicillin for treating G. vaginalis infections 6, 7