treatment of bacterial vaginosis

Last edited 07/2021 and last reviewed 06/2022

Treatment of first choice for Bacterial vaginosis/Gardnerella vaginalis is metronidazole e.g. 400-500mg twice daily for five to seven days (1).

  • for the treatment of bacterial vaginosis (BV), the recommended first line options are 400 mg twice daily oral metronidazole for 5 to 7 days, 0.75% metronidazole vaginal gel for 5 days or 2% clindamycin vaginal cream for 7 days (2)
    • Public Health England guidance states antibiotic options as:
      • oral metronidazole 400mg BD for 7 days; OR
      • oral metronidazole 2000mg stat; OR
      • metronidazole 0.75% vaginal gel 5g applicator at night for 5 nights OR
      • clindamycin 2% cream 5g applicator at night for 7 nights

    • dequalinium may be a suitable alternative treatment if:
        • women cannot tolerate metronidazole or clindamycin, or in other circumstances where those treatments are not suitable e.g. women with inflammatory bowel disease, or antibiotic-associated colitis where clindamycin is contraindicated
        • in situations where fewer treatments are available due to interactions or allergies, e.g. in pregnancy
        • where it would be beneficial to avoid use of an antibiotic (according to local specialist opinion, metronidazole resistance and clindamycin resistance is an increasing but under-recognised problem largely because women with BV are not tested for resistance)

Other treatment regimes that have been shown to be effective include tetracycline and douching therapy with povidone-iodine.

Bacterial vaginosis in pregnancy (3):

  • antibiotic treatment can eradicate bacterial vaginosis in pregnancy
  • this particular review however provides little evidence that screening and treating all pregnant women with asymptomatic bacterial vaginosis will prevent preterm birth and its consequences
  • for women with a previous preterm birth, there is some suggestion that treatment of bacterial vaginosis may reduce the risk of preterm prelabour rupture of membranes and low birthweight
  • antibiotic treatment during pregnancy (4):
    • standard treatment in the UK is oral metronidazole 400mg twice a day for five to seven days (1,2,4,8)
      • there are no reports of an increase in birth defects with the use of metronidazole during pregnancy - however, it is better to avoid its use in the first trimester, and recommendations from some experts suggest delaying breast-feeding until 24 hours after completing therapy

    • topical clindamycin is an alternative treatment option
      • Clindamycin 2% cream at night for 7 days (5)
    • dequalinium is another alternative to metronidazole (2)

Treatment of sexual partners of patient who has bacterial vaginosis:

  • at present, there is no evidence to support treatment of a male sexual partner - whether, in the context of a lesbian relationship, female partners could benefit from treatment is not known (6)
  • National guidance suggests (7) '...In the management of BV, testing and treatment of male sexual partners is not indicated but testing and treatment of female sexual partners can be considered...
    • studies have found high concordance rates of vaginal microflora amongst monogamous women who have sex with women consideration may be given to testing and treating female partners of women with BV

The summary of product characteristics must be consulted before prescribing any of the drugs mentioned.

Key points (8):

  • oral metronidazole is as effective as topical treatment, and is cheaper
    • 7 days results in fewer relapses than 2g stat at 4 weeks
  • pregnant/breastfeeding: avoid 2g dose of metronidazole
  • treating partners does not reduce relapse


  • dequalinium chloride is a quaternary ammonium compound that acts as a surface antiseptic agent
    • in 2015, a vaginal tablet formulation was licensed for the treatment of bacterial vaginosis
    • acts on bacterial cells to increase cell permeability and decrease bacterial enzyme activity leading to cell death
    • recommended dose and course of treatment is one vaginal tablet daily for six days. Tablets should be inserted deep within the vagina in the evenings before retiring

  • bacterial vaginosis
    • characterized by an overgrowth of predominantly anaerobic organisms (such as Gardnerella vaginalis, Prevotella species, Mycoplasma hominis, and Mobiluncus species) and a loss of lactobacilli