The effects of antimicrobial treatment on bacterial vaginosis in non-pregnant women  

Bacterial vaginosis (BV) is a very common cause of symptomatic and asymptomatic vaginal infection. It has been associated with a high incidence of obstetric and gynaecologic complications and an increased risk of transmission of HIV (human immunodeficiency virus). This review evaluated the effectiveness and adverse effects of antimicrobial agents used to treat BV in non-pregnant women. Twenty-four trials involving 4422 women were reviewed. With regard to less treatment failure, clindamycin was superior to placebo but comparable to metronidazole, irrespective of the dose regimen. Metronidazole tended to cause a higher rate of adverse events, such as metallic taste and nausea and vomiting, than did clindamycin. Oral lactobacillus combined with metronidazole was more effective than metronidazole alone. Administered in an intravaginal gelatin tablet, lactobacillus was also more effective than oral metronidazole. Triple sulfonamide cream was less effective compared with clindamycin. Hydrogen peroxide douche was not as effective as a single 2 g dose of metronidazole yet caused more harms. Only one trial involved asymptomatic women and the result was not conclusive. There was insufficient evidence to reach a conclusion on the effectiveness of other promising drugs. Drugs effective for bacterial vaginosis include clindamycin preparations, oral metronidazole, and oral and intravaginal tablets of lactobacillus. Adverse effects of metronidazole include metallic taste, and nausea and vomiting. Information on possible side effects of lactobacillus preparations is required.

Authors' conclusions: 

Clindamycin preparations, oral metronidazole, and oral and intravaginal tablets of lactobacillus were effective for bacterial vaginosis. Hydrogen peroxide douche and triple sulphonamide cream were ineffective. Metronidazole caused metallic taste, nausea and vomiting. We need better-designed trials with larger sample sizes to test the effectiveness of promising drugs.

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Background: 

Bacterial vaginosis (BV) is a very common cause of vaginitis that has been associated with a high incidence of obstetric and gynaecologic complications and increased risk of HIV-1 transmission. This has led to renewed research interest in its treatment.

Objectives: 

To assess the effects of antimicrobial agents on BV in non-pregnant women.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, LILACS, and African Healthline (December 2007); and proceedings of relevant international conferences (from 1981 to date).

Selection criteria: 

Randomised controlled trials comparing any two or more antimicrobial agents, or antimicrobial agents with placebo or no treatment, in women with clinical or Gram-stain criteria of BV.

Data collection and analysis: 

Two authors independently assessed trial quality and extracted data from the original publications while the third author cross checked the data.

Main results: 

Twenty-four trials involving 4422 participants were reviewed. Most examined symptomatic women only. Only seven trials analysed results by intention to treat; we re-analysed the remainder.

Compared with placebo, clindamycin showed a lower rate of treatment failure (relative risk (RR) 0.25, 95% confidence interval (CI) 0.16 to 0.37). Clindamycin and metronidazole showed identical rates of treatment failure, irrespective of regimen type, at two and four-week follow up (RR 1.01, 95% CI 0.69 to 1.46; RR 0.91, 95% CI 0.70 to 1.18, respectively). Clindamycin tended to cause a lower rate of adverse events (RR 0.75, 95% CI 0.56 to 1.02); metallic taste, and nausea and vomiting were more common in the metronidazole group (RR 0.08, 95% CI 0.1 to 0.59; RR 0.23, 95% CI 0.10 to 0.51, respectively). Given intravaginally as gelatin tablets, lactobacillus was more effective than oral metronidazole  (RR 0.20, 95% CI 0.05 to 0.08). Similarly, oral lactobacillus combined with metronidazole was more effective than metronidazole alone (RR 0.33, 95% CI 0.14 to 0.77). Clindamycin showed a lower rate of clinical failure than triple sulfonamide cream (RR 0.46, 95% CI 0.29 to 0.72). Hydrogen peroxide douche showed a higher rate of clinical failure (RR 1.75, 95% CI 1.02 to 3.00) and adverse events (RR 2.33, 95% CI 1.21 to 4.52) than a single 2 g dose of metronidazole.