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About clarithromycin

Clarithromycin is an antibiotic. It's used to treat chest infections such as pneumonia, skin problems such as cellulitis, and ear infections. It's also used to treat Helicobacter pylori, a bacteria that can cause stomach ulcers.

Clarithromycin is sometimes used by people who have an allergy to penicillin and antibiotics similar to penicillin, like amoxicillin.

Clarithromycin is only available on prescription.

It comes as tablets, granules, or a liquid that you drink. It can also be given by injection, but this is usually only done in hospital.

Key facts

  • You'll usually take clarithromycin twice a day: once in the morning and once in the evening.
  • Some people take slow-release clarithromycin tablets. This means that the medicine is gradually released into your body over 24 hours. These are taken once a day.
  • For most infections, you should feel better within a few days.
  • The most common side effects of clarithromycin are feeling sick (nausea) or being sick (vomiting), stomach cramps, and diarrhoea.
  • You can drink alcohol while taking clarithromycin.

Page last reviewed: 26 January 2022
Next review due: 26 January 2025