Like all medicines, benzydamine can cause side effects in some people, but many people have no side effects or only minor ones.
Side effects of benzydamine
Some people get a stinging feeling or numbness in their mouth after using benzydamine. If you're using the spray, this feeling may last a few minutes.
If you get numbness or stinging with the mouthwash, try adding some water (up to 15ml) to your dose. You can mix the mouthwash and water in a cup or glass if you need to.
Serious allergic reaction
In rare cases, benzydamine may cause a serious allergic reaction (anaphylaxis).
Immediate action required: 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.
Do not drive yourself to A&E.
The person you speak to at 999 will give you advice about what to do.
Other side effects
These are not all the side effects of benzydamine. For a full list see the leaflet that comes with your medicine.
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.