Side Effects Of Flucloxacillin

Like all medicines, flucloxacillin can cause side effects in some people, although not everyone will get them.

Common side effects of flucloxacillin

These common side effects of flucloxacillin happen in more than 1 in 100 people. There are things you can do to help cope with them:

Keep taking flucloxacillin, but talk to your doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects

Serious side effects are rare and happen in less than 1 in 10,000 people.

Stop taking the medicine and call your doctor or 111 straight away if:

• you get diarrhoea (possibly with muscle cramps) that contains blood or mucus, or severe diarrhoea
• you have pale poo with dark pee, and the whites of your eyes or skin turn yellow (this may be less obvious on black or brown skin) - this can be a sign of liver problems
• you get blisters, ulcers or a severe rash with reddening, peeling and swelling of the skin
• you get bruising or changes in your skin colour

Tell your doctor or call 111 straight away if you have joint or muscle pain that starts after about 2 days of taking the medicine.

Some of these serious side effects may not happen for up to 2 months after finishing the course of flucloxacillin.

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to flucloxacillin.

Call 999 now if:

• your lips, mouth, throat or tongue suddenly become swollen
• you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
• your throat feels tight or you're struggling to swallow
• your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
• you suddenly become very confused, drowsy or dizzy
• someone faints and cannot be woken up
• a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

Other side effects

These are not all the side effects of flucloxacillin. For a full list, see the leaflet inside your medicines packet.

Reporting side effects

You can report any suspected side effect using the Yellow Card safety scheme.

Visit the Yellow Card website for more information about reporting side effects.

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