Common side effects

Lidocaine mouth and throat treatments are generally very safe. People rarely have any side effects.

However, as with all medicines, it's possible to be unexpectedly allergic to lidocaine.

Serious allergic reaction

It's extremely rare to have an allergic reaction (anaphylaxis) to lidocaine.

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.

Do not drive yourself to A&E.

The person you speak to at 999 will give you advice about what to do.

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

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