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About flucloxacillin

Flucloxacillin is a type of penicillin antibiotic.

It's used to treat a variety of infections including:

Flucloxacillin is only available on prescription.

It comes as capsules, or as a liquid for children and people who find it difficult to swallow capsules.

It can also be given by injection, but this is usually done in hospital.

Key facts

  • You'll usually take flucloxacillin 4 times a day to treat an infection.
  • For most infections, you should start to feel better within a few days.
  • Take flucloxacillin on an empty stomach. This means at least 60 minutes before a meal or snack, or at least 2 hours after.
  • The most common side effects are feeling sick and diarrhoea.
  • You can drink alcohol while taking flucloxacillin.
  • You can take flucloxacillin during pregnancy or while you're breastfeeding.

Page last reviewed: 26 June 2025
Next review due: 26 June 2028