An antiplatelet ("blood-thinning" tablet)
Clopidogrel
An antiplatelet tablet that makes platelets less "sticky" to help prevent clots after a stroke or mini-stroke (TIA), heart disease or a stent.
What is Clopidogrel?
Clopidogrel is an antiplatelet medicine that makes the blood less likely to clot inside an artery. It is used to help prevent heart attacks and strokes, and after procedures such as having a stent fitted, often alongside low-dose aspirin for a set period.
Education and reference only. This is a plain-language guide to Clopidogrel — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Clopidogrel is one of the most widely used antiplatelet medicines in the UK. It is taken to lower the chance of a clot forming inside an artery — the kind of clot that causes a stroke, a mini-stroke (TIA), a heart attack or a blockage in the legs. It is commonly used after a stroke or TIA, in people with coronary heart disease, and after a stent has been placed in a heart artery. It is a long-term, once-daily tablet that works quietly in the background to reduce risk; it does not treat symptoms you can feel day to day.
How it works
Platelets are tiny blood cells that clump together to plug a damaged blood-vessel wall — useful for stopping bleeding, but harmful when a clump forms inside a furred-up artery and blocks it. Clopidogrel blocks one of the signals (the P2Y12 receptor) that platelets use to stick to one another, so they are less likely to form a clot. The effect lasts for the life of each platelet, so it builds up over a few days and wears off gradually after stopping as the body makes fresh platelets.
Company & origin
Originated / developed by: Sanofi (with Bristol-Myers Squibb).
Clopidogrel was discovered by the French company Sanofi (Sanofi Recherche), with the compound first synthesised in the mid-1980s. It was co-developed and marketed with Bristol-Myers Squibb as Plavix, receiving US FDA approval in 1997.
What it treats
Conditions Clopidogrel is used for
Practical use
How to take Clopidogrel
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it at the same time each day, with or without food; a routine helps you remember.
- Because it reduces clotting, expect easier bruising and longer bleeding from minor cuts, and report any unusual or heavy bleeding.
- Do not stop taking it without medical advice, as stopping early can sharply raise the risk of a clot, heart attack or stent blockage.
- Tell any doctor, dentist or pharmacist that you take clopidogrel before surgery, dental work or starting new medicines.
- Mention if you take indigestion remedies such as omeprazole, as some can affect how well clopidogrel works.
Weighing it up
Advantages & disadvantages of Clopidogrel
Advantages
- Effectively lowers the risk of heart attack, stroke and clots in people at high risk.
- Taken once a day, which is simple to fit into a daily routine.
- Can be used in people who cannot tolerate aspirin.
- A well-established, widely studied treatment with decades of clinical use.
Disadvantages
- Increases the risk of bleeding and bruising, sometimes serious.
- Stopping suddenly can trigger a dangerous clot, so it must not be stopped without advice.
- Usually needs to be paused before surgery, raising clot risk during that gap.
- Some people respond less well because of how their body activates the medicine.
- Can interact with certain stomach-acid medicines and other blood thinners.
Practical use
Good to know
It is taken once a day, with or without food, and is taken long-term — often for life after a stroke, TIA or heart event, or for a defined period after a stent. Sometimes it is used together with low-intensity aspirin ("dual" antiplatelet therapy) for a while. Because it makes bleeding harder to stop, you may bruise more easily and bleed for longer from cuts. If you need surgery or a dental procedure, tell the team you take it — but only stop it on a doctor's advice, as stopping suddenly can be risky. If you also need a stomach-protection medicine (a PPI), omeprazole and esomeprazole are usually avoided because they can blunt clopidogrel's effect; lansoprazole or pantoprazole are preferred.
Who should not take it / use with caution
- People with active bleeding, such as a bleeding stomach ulcer or bleeding in the brain.
- People with severe liver disease, or a known allergy to clopidogrel.
- Used with caution before planned surgery, in people at high risk of bleeding, and alongside other medicines that increase bleeding.
Monitoring
- For signs of bleeding or unusual bruising
- Review before planned surgery or dental work
- That any PPI used alongside it is a suitable one
Side effects
- Bleeding and bruising more easily — nosebleeds, bleeding gums, or bleeding that takes longer to stop.
- Indigestion, tummy upset or diarrhoea.
- Rarely, a serious bleed (for example black or bloodstained stools, or vomiting blood) — seek urgent help. Very rarely, a blood disorder; report unusual bruising, a rash of tiny blood spots, or feeling suddenly very unwell.
Key interactions
- Omeprazole and esomeprazole can reduce how well clopidogrel works and are usually avoided with it — lansoprazole or pantoprazole are preferred if a PPI is needed.
- Other "blood thinners" (anticoagulants such as warfarin or apixaban), aspirin and anti-inflammatory painkillers (NSAIDs) add to the bleeding risk.
- Some antidepressants (SSRIs/SNRIs) and certain other medicines can also increase the chance of bleeding.
Available as: Tablets. A liquid or dispersible option is sometimes available for people who cannot swallow tablets.
Answers
Clopidogrel: frequently asked questions
Is clopidogrel a blood thinner?
It is often called one, but more precisely it is an antiplatelet — it makes platelets less sticky so clots are less likely to form. This is different from anticoagulants such as warfarin or apixaban, which work on the clotting proteins in blood. Both reduce clotting but in different ways.
Why can't I take omeprazole with clopidogrel?
Omeprazole and esomeprazole can interfere with the way the body activates clopidogrel, which may make it work less well. If you need a stomach-protection medicine, lansoprazole or pantoprazole are usually chosen instead. Mention any heartburn remedies you buy yourself to your pharmacist.
I have surgery coming up — should I stop clopidogrel?
Always tell the surgical or dental team that you take it, but never stop it on your own. Whether it is paused depends on the procedure and your clot risk, and stopping at the wrong time can trigger a stroke or heart attack. The decision is made by the team who know your full picture.
I bruise more easily now — is that normal?
Easier bruising and bleeding a little longer from cuts are expected, because clopidogrel deliberately makes clotting slower. Tell your doctor if bruising is heavy or unexplained, or if you have signs of internal bleeding such as black stools or blood in vomit, which need urgent attention.
What is the difference between clopidogrel and Plavix?
They are the same medicine — clopidogrel is the generic (active-ingredient) name and Plavix is a brand name. Generic clopidogrel contains the identical active ingredient.
The wider class
About Antiplatelet drugs
Clopidogrel belongs to the antiplatelet drugs class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF: Clopidogrel.
- electronic Medicines Compendium (SmPC): Clopidogrel (Plavix).
- NICE CKS: Clopidogrel.
- NICE: Stroke and TIA — antiplatelet treatment.
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