Like all medicines, nefopam can cause side effects. However, many people have no side effects or only minor ones.
Common side effects
There are things you can do to help with these possible side effects of nefopam:
Feeling sick (nausea)
It may help if you take nefopam after eating and avoid eating rich or spicy food.
Feeling dizzy or lightheaded
If nefopam makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until you feel better. If you still feel dizzy, lie down so that you do not faint, then sit up for a while until you feel better.
Do not drive, ride a bike, or use tools or machinery if you're feeling dizzy. Do not drink alcohol as it will make you feel worse.
Feeling nervous, confused or shaky
Stop what you're doing and sit or lie down until you feel better. Speak to your doctor if the feeling does not go away.
A dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Difficulty peeing
Relax when you try to pee. Do not try to force yourself to pee. If it does not happen, try again later.
Talk to your doctor if this does not get better. Contact your doctor urgently if you cannot pee at all.
Numbness or tingling in your hands and feet
Talk to your doctor if this does not go away.
Speak to a 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.
Nefopam may also colour your pee pink. But do not worry, this is harmless and does not last long.
If you are over 65 years old, you may be more likely to get some side effects, such as feeling confused or hallucinating.
Serious side effects
Stop taking nefopam and call your doctor or call 111 straight away if:
- you're seeing things that are not there (hallucinations)
- you get a fast heartbeat
Immediate action required: Call 999 if:
- you have a seizure or fit
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to nefopam.
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.
Long-term side effects
If you take nefopam for a long time, it's possible to become addicted.
If this happens to you, you might have withdrawal symptoms if you suddenly stop taking it. These symptoms can include feeling anxious or restless or having problems sleeping.
If you've taken nefopam for a long time, speak to your doctor if you want to stop taking it. They may want you to reduce your dose gradually, to prevent withdrawal symptoms.
Other side effects
These are not all the side effects of nefopam. For a full list see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.