Like all medicines, clopidogrel can cause side effects, although not everyone gets them.
Common side effects of clopidogrel
These common side effects of clopidogrel happen in more than 1 in 100 people. There are things you can do to help cope with them:
Bleeding more easily than normal
Clopidogrel can cause bleeding problems such as nosebleeds, bruising more easily, heavier periods or bleeding that takes longer to stop.
Be careful when doing activities that might cause an injury or a cut. Always wear a helmet when cycling. Wear protective gloves when you use sharp objects like scissors, knives, and gardening tools. Use an electric razor instead of wet shaving. Speak to a dentist for advice on how to clean your teeth.
See a doctor if you're worried about any bleeding.
Diarrhoea
Drink lots of fluids, such as water or squash, to avoid dehydration. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
If you take the combined contraceptive pill or progestogen-only pill and you have severe, watery diarrhoea, or any diarrhoea that lasts for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Stomach pain
Try to rest and relax. It can help to eat and drink slowly and have smaller and more frequent meals. Putting a heat pad or covered hot water bottle on your stomach may also help.
If you're in a lot of pain or it does not get better, speak to your pharmacist or doctor.
Indigestion or heartburn
Take clopidogrel a few minutes before or after a meal.
If the indigestion does not go away, it could be a sign that you have a stomach ulcer. Talk to your doctor, as they may prescribe something to protect your stomach or switch you to a different medicine.
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.
Serious side effects
Serious side effects are rare and happen in less than 1 in 1,000 people.
Call a doctor or call 111 straight away if:
- there's blood in your pee
- there's blood in your poo, or you have black poo that looks like tar
- the whites of your eyes turn yellow, or your skin turns yellow, although this can be harder to see on brown or black skin – these can be signs of liver problems
- you feel very tired or have signs of infection, such as a high temperature or sore throat – these can be signs of a blood or bone marrow disorder
Immediate action required: Go to A&E now if:
- you're coughing up blood
- you're vomiting blood, or there's something that looks like coffee grounds in your vomit
- you have a nosebleed that you cannot stop and lasts longer than 10 to 15 minutes
Do not drive to A&E. Ask someone to drive you or call 999 and ask for an ambulance.
Bring all the medicines you take with you.
Serious allergic reaction
In rare cases, clopidogrel can 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 clopidogrel. For a full list, see the leaflet inside your medicines packet.
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.