Like all medicines, pseudoephedrine can cause side effects, although not everyone gets them.
Common side effects
These common side effects of pseudoephedrine happen in more than 1 in 100 people. There are things you can do to help cope with them:
Feeling sick (nausea)
Try taking pseudoephedrine with or after a meal or snack. Stick to simple meals and it may also help if you do not eat rich or spicy food.
Headaches
Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask a pharmacist to recommend a painkiller.
If your headache does not go away, or gets worse, stop taking pseudoephedrine and contact 111. It may be because pseudoephedrine can increase your blood pressure.
A dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Feeling restless, nervous or shaky
Stop taking pseudoephedrine and talk to a doctor if symptoms do not go away. Ask a pharmacist about trying a different medicine.
Difficulty sleeping
Try not to have a big meal in the evening and avoid drinking alcohol or drinks with caffeine such as tea or coffee. Try not to watch television or use your mobile phone before going to bed. Try to relax for an hour before bedtime.
Talk to a pharmacist or doctor if the advice does not help and any of these side effects bother you or will not go away.
Serious side effects
Stop taking the medicine and call 111 straight away if:
- you have a fast, irregular or pounding heartbeat (palpitations) that does not stop or comes back
- you suddenly get a high temperature, your skin reddens or lots of pustules (small, fluid or pus-filled bumps) appear on your skin. These are possible symptoms of acute generalised exanthematous pustulosis (AGEP). This may happen within the first 2 days of taking pseudophedrine
- you suddenly feel sick or are suddenly being sick. If this happens, stop taking pseudoephedrine straight away. This could be a sign of very rare but serious conditions that can involve inflammation of the brain or reduced blood supply to the brain
Immediate action required: Call 999 or go to A&E if:
- you have a severe headache that comes on very quickly
- you start feeling confused
- you've had a fit or seizure
- you have changes in your vision
Stop taking pseudoephedrine straight away if you have any of these side effects. These can be signs of very rare but serious conditions that can involve inflammation of the brain or reduced blood supply to the brain.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to pseudoephedrine.
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.
Other side effects
These are not all the side effects of pseudoephedrine. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.