The NHS dispenses around 11 million units of this drug every year

02:08, 03 Jan 2026Updated 12:57, 03 Jan 2026

Man taking tabletThe NHS warned that clopidogrel could cause four “common” side effects(Image: Getty)

Patients who take a commonly prescribed drug have been warned of four potential side effects. According to the NHS, these symptoms affect more than one in 100 people.

On its website, the NHS offers guidance on taking clopidogrel, an antiplatelet medicine. Also known by its brand names Grepid and Plavix, it prevents platelets from sticking together and forming a dangerous blood clot.

This is typically prescribed to people who have a high risk of a blood clot forming to prevent a heart attack, stroke, or other serious cardiovascular events. However, as is the case with any medication, it does come with some potential side effects.

The NHS says: “Like all medicines, clopidogrel can cause side effects, although not everyone gets them. These common side effects of clopidogrel happen in more than one in 100 people.”

These are:

Bleeding more easily than normalDiarrhoeaStomach painIndigestion or heartburn

It continues: “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.”

Stomach painStomach pain is one potential side effect of this drug(Image: Getty)Serious side effects

Serious side effects are “rare” and happen in less than 1 in 1,000 people. You should call a doctor or call 111 straight away if:

There’s blood in your urineThere’s blood in your poo, or you have black poo that looks like tarThe whites of your eyes turn yellow, or your skin turns yellowYou feel very tired or have signs of infection, such as a high temperature or sore throat

The NHS adds that you should “go to A&E now” if:

You’re coughing up bloodYou’re vomiting blood, or there’s something that looks like coffee grounds in your vomitYou have a nosebleed that you cannot stop and lasts longer than 10 to 15 minutesBlood clotClopidogrel it prevents platelets from sticking together and forming a dangerous blood clot(Image: Getty)Who cannot take clopidogrel

Clopidogrel is not suitable for some people. To make sure it’s safe for you, the NHS says you should tell your doctor if you:

Have ever had an allergic reaction to clopidogrel or any other medicineHave ever had a stomach ulcerHave recently had surgery or a serious injuryHave had bleeding in your brain (a brain haemorrhage)Have a bleeding disorder, such as haemophiliaHave liver or kidney problemsAre trying to get pregnant, already pregnant or breastfeedingTaking it with other medications

Some medicines affect the way clopidogrel works. The NHS says you should tell your doctor if you’re taking any other medicines, including:

Other medicines to prevent blood clots, such as low-dose aspirin, warfarin, rivaroxaban, apixaban, edoxaban, dabigatran, dipyridamole, ticagrelor or prasugrelNon-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofenAntidepressants called selective serotonin reuptake inhibitors (SSRIs), such as citalopramOmeprazole or esomeprazole, for indigestion and heartburnRosuvastatin, a medicine for high cholesterolRifampicin, an antibioticMedicines to treat epilepsy, such as carbamazepineMedicines to treat HIV, such as efavirenzMedicines to treat type 2 diabetes, such as pioglitazone or repaglinide

The NHS adds: “These are not all the medicines that may cause problems if you take them with clopidogrel. For a full list, see the leaflet inside your medicine packet.”