Like all medicines, sumatriptan can cause side effects. However, many people have no side effects or only minor ones.
Common side effects
These common side effects of sumatriptan happen in more than 1 in 100 people. They're usually mild and do not last long. Some of the side effects are similar to the symptoms of migraine or cluster headaches. There are things you can do to help cope with them:
Feeling or being sick (nausea or vomiting)
These symptoms may be due to the migraine itself.
If you feel able to eat, stick to simple meals and do not eat rich or spicy food.
If you're being sick, try small frequent sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
If you take the combined contraceptive pill or progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Feeling dizzy, unsteady on your feet or tired
If you begin to feel dizzy, lie down so that you do not faint, then sit until you feel better. Do not drive or use tools or machines if you feel dizzy, unsteady or tired.
Feeling hot or cold, face flushes red
If this bothers you or does not go away, speak to your doctor.
Irritation or burning in your nose or throat after using the nasal spray
This usually only lasts for a short time.
Nosebleeds after using the nasal spray
These nosebleeds will usually only last for a short time.
Seek immediate medical help if the bleeding does not stop after 10 to 15 minutes, especially if you're taking a medicine to prevent blood clots such as warfarin or rivaroxaban, or you have haemophilia or any other condition that means your blood cannot clot properly.
Bad taste in your mouth after using the nasal spray
Try chewing sugar-free gum.
Bruising or swelling where you gave yourself the injection
The injection may cause local reactions (the place where you injected yourself), such as pain, swelling, bleeding or bruising. This is usually mild and will go away after a few days.
See a doctor if it gets worse, becomes painful or inflamed or if it lasts for longer than a few days.
Talk to your doctor or pharmacist if the advice on how to cope does not help and these side effects bother you or last more than a few days.
Serious side effects
It happens rarely, but some people have serious side effects when taking sumatriptan.
Do not take any more sumatriptan and tell a doctor urgently, or call 111 straight away if you get continued or increasing:
- tightness or tingling in your face, arms, legs or chest
- unusual feelings of heaviness in your face, arms, legs or chest
- feelings of warmth or cold in your face, arms, legs or chest
These feelings usually do not last for long. If they continue, or become severe or intense, seek medical help straight away.
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to sumatriptan.
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 sumatriptan. For a full list, see the leaflet inside your medicine packet.
You can report any suspected side effect using the Yellow Card safety scheme.