Common questions about clopidogrel - Brand names: Grepid, Plavix

Clopidogrel slows the blood's clotting action by making platelets less sticky. Platelets are blood cells that stick together to block cuts and breaks in blood vessels.

But if you're at risk of heart attack or stroke, platelets can stick together inside already narrowed blood vessels to form a clot. The clot can stop blood flowing to the heart or brain and cause a heart attack or stroke.

If you take it every day, clopidogrel stops platelets clumping together to form unwanted blood clots. This helps to prevent heart attacks and strokes.

Clopidogrel works within 1 hour of taking it.

You may not feel any different after you start taking clopidogrel. However, this does not mean that the medicine is not working.

Carry on taking clopidogrel even if you feel well, as you'll still be getting the benefits.

Clopidogrel is generally OK to take for a long time. In fact, it works best if you take it for many months or even years.

If you're at risk of getting a stomach ulcer, your doctor may prescribe a medicine to help protect your stomach while you're taking clopidogrel.

Do not stop taking clopidogrel without talking to your doctor.

If you stop taking clopidogrel, your blood will start clotting at the same rate as before you started taking it, usually within around a week of stopping the medicine. This means you may be at increased risk of serious problems like heart attacks or strokes.

Other antiplatelet medicines include low-dose aspirin, dipyridamole and ticagrelor.

Anticoagulant medicines such as apixaban, dabigatran, edoxaban, rivaroxaban and warfarin are also prescribed to help prevent blood clots.

Not all medicines that prevent blood clots are suitable for everyone.

Talk to your doctor or pharmacist to find out why you've been recommended a particular medicine.

Both clopidogrel and ticagrelor work to:

• help prevent blood clots
• help prevent future heart attacks, if you've already had a heart attack

But ticagrelor is not approved for preventing further strokes if you've already had a stroke. In this case, your doctor may prescribe clopidogrel instead.

You'll usually take clopidogrel once a day. Ticagrelor is taken twice a day.

Clopidogrel may be less likely to cause bleeding than ticagrelor.

Because of the risk of bleeding, you may need to stop taking clopidogrel for a short time before having surgery or dental work.

Do not stop taking clopidogrel without first talking to your doctor or dentist. They'll tell you if you need to stop taking it before a procedure.

Yes, you can have vaccinations while taking clopidogrel.

It's a good idea to mention to the doctor or nurse that you're taking an antiplatelet medicine.

Clopidogrel does not affect any type of contraception, including the combined contraceptive pill, progestogen-only pill and emergency contraception.

However, if clopidogrel makes you have severe, watery diarrhoea, or any diarrhoea that lasts for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.

Find out more:

• What to do if you're sick or have diarrhoea when taking the combined pill
• What to do if you're sick or have diarrhoea when taking the progestogen-only pill

Clopidogrel does not affect your concentration, so you can drive or ride a bike while you're taking it.

Yes, you can drink alcohol while taking clopidogrel, as long as you stick to the national guidelines of no more than 14 units a week for men and women.

Drinking too much alcohol while you're taking clopidogrel can irritate your stomach. There's a risk that you could get a stomach ulcer.

Do not drink grapefruit juice while taking clopidogrel.

Grapefruit juice decreases the effects of your medicine, so that it may not work as well to prevent blood clots.

If you've been prescribed clopidogrel, you can also boost your health by making some key lifestyle changes.

• Quit smoking – smoking increases your heart rate and blood pressure. Quitting smoking will cut your risk of heart attack and stroke. Try to avoid secondhand smoke, too.
• Cut down on alcohol – try to keep to the recommended guidelines of no more than 14 units of alcohol a week, spread across 3 or more days.
• Exercise – regular exercise keeps your heart and blood vessels in good condition. It does not need to be too energetic. Walking every day is enough.
• Eat well – aim to eat a diet that includes plenty of fruit and vegetables, wholegrains, fat-free or low-fat dairy products and lean proteins. It's a good idea to limit the amount of salt in your diet too. Aim for no more than 6g of salt a day.
• Manage stress – when you're anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up. This raises your risk of heart attack and stroke. Find ways to reduce stress in your life. To give your heart a rest, try napping or putting your feet up when possible. Spend time with friends and family to be social and help reduce stress.
• Vaccinations – if you have heart failure, it's recommended that you have the flu vaccine every year and the pneumococcal vaccine, RSV vaccine and COVID-19 vaccine as recommended by your GP. Ask your doctor about these vaccinations. You can have them free on the NHS.