Side Effects Of Metronidazole - NHS

Common side effects of metronidazole

There are things you can do to help cope with these common side effects of metronidazole.

Feeling or being sick (nausea or vomiting)

Stick to simple meals and do not eat rich or spicy food. Always try to take your metronidazole after a meal or snack.

If you're being sick, try small frequent sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

Contact your doctor for advice if you're being sick for more than 24 hours.

If you take the combined pill or progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Diarrhoea

Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

Contact your doctor for advice if your diarrhoea continues for more than 24 hours. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take the combined pill or progestogen-only pill and you have severe, watery diarrhoea or any diarrhoea that lasts for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

A metallic taste in your mouth or a furry tongue

Drink plenty of water and eat plain foods that you usually enjoy.

If your tongue is very furry, this could be a sign of thrush. Ask your pharmacist or doctor for advice.

Problems with your skin

If you're using metronidazole cream or gel, you may experience dry skin, itching, discomfort or irritation, or redness (this may be harder to see on brown or black skin).

Try using the cream or gel less often (maybe once a day instead of twice, or every other day), or you could stop using it for a few days until the irritation goes away and then try using it again. If the irritation does not go away, stop using the cream or gel and speak to your doctor.

Talk to your doctor or pharmacist if this advice does not help and a side effect bothers you or does not go away.