Metronidazole

How to take metronidazole

Metronidazole is an antibiotic that comes as a tablet. To treat BV, take 1 tablet twice a day for 7 days.

Swallow the tablets with water, during or after a meal. Do not chew the tablets.

Take all of the tablets, even if your symptoms improve before you finish the course.

If you miss a dose of metronidazole, take it as soon as you remember. If it’s nearly time for your next dose, leave the missed dose and take your next dose at the usual time.

This medication is safe to use when you’re pregnant or breastfeeding. It can make breast milk taste different, which might make feeding harder.

You should not drink alcohol while taking this medication and for 48 hours (2 days) after your last dose. Metronidazole can interact with alcohol and cause side effects like being sick, flushing or a racing heart. Even small amounts of alcohol can bring on side effects.

Side effects of metronidazole

Not everyone will  get side effects when they take metronidazole, but you might experience:

• feeling or being sick (nausea)

• diarrhoea

To help manage these side effects, take the tablets after eating, eat plain, non-spicy foods and drink plenty of water.

If you are sick or have diarrhoea for more than 24 hours, contact a doctor.

About bacterial vaginosis

Bacterial vaginosis (BV) is caused by changes to the natural bacteria in the vagina. The imbalance of bacteria can cause changes to vaginal discharge.

You might have BV if you notice your discharge:

• has a strong fishy smell, particularly after sex

• is a white or grey colour

• is thin and watery

BV does not cause any itchiness or pain. If you have these symptoms as well as changes to your discharge, contact your GP or sexual health clinic for an appointment. You might also want to test at home for trichomoniasis, as this can cause these symptoms.

BV is not an STI and you can get it without having sex. But you are more likely to experience it if you are sexually active. 

BV is not usually serious, but it does need treatment. Left untreated, it can increase your risk of getting STIs. And if you’re pregnant, there’s a small chance having BV could cause complications.

How to avoid BV

Often, BV will come back and you will need to treat it again. There are some things you can try yourself to reduce the chance of it returning and to help any symptoms.

Your vagina does a great job of keeping itself clean, so caring for your genitals does not need to be complicated. Washing the external area daily with warm water when you’re having a bath or shower is all you need. Even gentle soaps can cause irritation.

You should avoid:

• Perfumed soaps, shower gels and lotions

• Intimate or vaginal washes or deodorants

• Douching or washing inside the vagina

• Over-washing - once a day is all you need

If you smoke, this can increase your chance of getting BV. The best way to stop smoking is with specialist support and treatment, you can find free specialist services or speak with your GP about stopping.

Using barrier methods like condoms, gloves and dental dams during sex can help prevent BV.

If you get recurring BV – getting it more than 3 times a year – you may be referred to a genitourinary medicine (GUM) specialist to discuss longer-term treatments.