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About metronidazole

Metronidazole is an antibiotic.

It's used to treat skin infections, rosacea and mouth infections, including infected gums and dental abscesses. It's also used to treat conditions such as bacterial vaginosis and pelvic inflammatory disease.

It's also used for infected insect bites, skin ulcers, bed sores and wounds, and to treat and prevent bacterial and parasitic infections.

Metronidazole is only available on prescription.

It comes as tablets, gel, vaginal gel, cream, a liquid you drink or a suppository which is a medicine that you push gently into your anus (bottom). It's also given by injection, but this is usually only done in hospital.

Key facts

  • The most common side effects of metronidazole tablets, liquid, suppositories or vaginal gel are feeling sick (nausea) or being sick (vomiting), diarrhoea, and a slight metallic taste in your mouth.
  • It's unusual to have any side effects from metronidazole cream or gel.
  • Do not drink alcohol while taking a course of metronidazole tablets, liquid, suppositories or vaginal gel, or for 2 days after finishing treatment. Alcohol can cause side effects such as feeling and being sick, stomach pain, hot flushes, difficulty breathing, a pounding heartbeat (palpitations) and headaches.
  • For most infections, you'll start to feel better in a few days, but for some it may take longer. When treating rosacea, you may only notice a difference after several weeks.
  • It's important to take metronidazole as your doctor tells you, and finish your full course of treatment.

Page last reviewed: 17 November 2021
Next review due: 17 November 2024