Antiplatelets, clopidogrel

Page last reviewed: 13/07/2011

Clopidogrel (brand name Plavix) is an antiplatelet medicine. This means it lowers the risk of clots forming in your blood.

You may be given Clopidogrel if you have had:

  • a heart attack
  • a stroke
  • acute coronary syndrome (minor heart attack or unstable angina)
  • a coronary stent (a device to open up a blocked artery to the heart)

Clopidogrel may also be used instead of low-dose aspirin if you are allergic to aspirin and are considered to be at risk of having a heart attack or stroke. For example, if you:

  • have high cholesterol
  • have high blood pressure
  • have diabetes
  • smoke

How it works

Antiplatelet medicines reduce the risk of clots forming in the blood. This cuts your risk of having a stroke or heart attack. Normally, when there is a cut or break in a small blood vessel, a blood clot forms to plug the hole until the blood vessel heals.

Small cells in the blood called platelets make the blood clot. When a platelet detects a damaged area of a blood vessel, it produces a chemical that attracts other platelets and makes them stick together to form a blood clot.

Clopidogrel reduces the ability of the platelets to stick together and reduces the risk of clots forming.

Clopidogrel and low-dose aspirin

Sometimes, you may be given both low-dose aspirin and clopidogrel to take together for a period of treatment. Taken together, they are very effective, but there is a higher risk of bleeding, usually in the gut. This risk increases with age. The key question for your doctor is whether the benefits outweigh the extra risk.

This combination treatment should usually be taken for no longer than 9-12 months. After this period, just take low-dose aspirin.

Useful Links

Page last reviewed: 13/07/2011

When to avoid clopidogrel

Clopidogrel should not be taken if you have:

  • an active (bleeding) peptic ulcer
  • recently had a brain haemorrhage

Surgery or dentistry

Some people are advised to stop taking clopidogrel seven days before a planned operation or dental extraction (removal of a tooth). This should always be on the advice of your GP, surgeon or dental surgeon.

Pregnancy and breastfeeding

Clopidogrel is not recommended if you are pregnant or breastfeeding. This is because there is very little information on its use in pregnant and breastfeeding women.

Using clopidogrel with caution

Clopidogrel should be taken with caution if you:

  • have liver problems
  • have kidney problems
  • are at risk of bleeding, for example, if you are at risk of peptic ulcers

Useful Links

Page last reviewed: 13/07/2011

Common side effects

Common side effects of clopidogrel can include:

  • diarrhoea
  • indigestion (dyspepsia)
  • pains in your stomach and bowel
  • nosebleeds
  • bruising
  • blood in your urine
  • blood in your stools

Less common side effects

Less common side effects of clopidogrel include:

  • headaches
  • dizziness
  • rashes and itching
  • pins and needles
  • peptic ulcer (an ulcer in the digestive tract)
  • gastritis (inflammation of the stomach lining)
  • nausea
  • vomiting 
  • constipation
  • flatulence (wind) 
  • increased bleeding (your blood taking longer to clot - for example, when you cut yourself)
  • white blood cell disorders (for example, reduced white blood cells in the blood)

Ability to drive

Clopidogrel is unlikely to affect your ability to drive.

However, some people may sometimes feel dizzy when taking clopidogrel. Avoid driving if you feel dizzy.

Useful Links

Page last reviewed: 13/07/2011

When two or more medicines are taken at the same time, the effects of one of the medicines can alter the effects of the other. This is known as a drug-drug interaction. Clopidogrel can interact with other medicines.

Some of the more common interactions are listed below. However, this is not a complete list.

If you want to check that your medicines are safe to take with clopidogrel, ask your doctor or pharmacist or read the patient information leaflet that comes with your medicine.

Anti-inflammatory painkillers

There is an increased risk of bleeding when clopidogrel is taken with non-steroidal anti-inflammatory painkillers (NSAIDs), such as diclofenac, ibuprofen and naproxen.

Dipyridamole

Dipyridamole is another type of antiplatelet. If you take this with clopidogrel, there is an increased risk of bleeding.

Warfarin

Warfarin is an anticoagulant that prevents your blood from clotting. Clopidogrel taken in combination with warfarin can increase your risk of bleeding.

Useful Links

Interactions with food and alcohol

There are no dangerous interactions between clopidogrel and food or alcohol, although major changes in diet (especially involving salads, vegetables and drinking alcohol) may affect anticoagulant control.

Page last reviewed: 13/07/2011

Missed doses

If you forget to take your dose of clopidogrel, take that dose as soon as you remember, then continue to take your course of clopidogrel as normal.

However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

If you have to take two doses closer together than normal, there is an increased risk of side effects.

You can also check the patient information leaflet that comes with your medicine. It should give you advice about what to do.

Accidentally take an extra dose

If you accidentally take an extra dose or doses of clopidogrel, contact your GP or your GP out of hours service.

Useful Links

Content provided by NHS Choices www.nhs.uk and adapted for Ireland by the Health A-Z.

Browse Health A-Z