Clopidogrel (oral)

Clopidogrel is used to treat vulnerable patients who may be at risk of suffering heart failure or cerebrovascular accident.


Clopidogrel is a platelet inhibitor that is used to reduce the likelihood of a patient suffering a cerebrovascular accident or a heart attack. The drug is generally administered to people who have a history of chest pains, cerebrovascular accident, or heart attack, and is often used together with aspirin. Patients who have circulatory problems may also be treated with clopidogrel.

A cerebrovascular accident or a heart attack can be caused when a vein becomes obstructed by a blood clot. Platelet inhibitors work by reducing the clotting ability of the blood through stopping the platelets in the blood from sticking together to form a clot. It should be noted that clopidogrel can increase the risk of severe bleeding in vulnerable patients.

In the US, clopidogrel is sold under the brand name, Plavix and can only be obtained from your pharmacist with a doctor’s prescription. Plavix is taken orally in tablet form.

Conditions treated

• reduce risk of heart attack or cerebrovascular accident
• circulatory disorders

Type of medicine

• platelet inhibitor


In addition to its desired effects, clopidogrel can cause some side effects. These effects may not affect everyone, but if you do notice them, you may need to seek further medical attention. If you experience any of the effects listed below, contact your GP or specialist straight away:

• yellow skin or eyes
• white spots, ulcers, or sores in the mouth
• wheezing
• vomiting of blood or debris resembling coffee grounds
• unusual bruising or bleeding
• tightness of the chest
• swollen lymph glands
• swelling of the inside of the nose, eyes or face
• sweating
• sudden weakness
• stomach or upper right abdominal pain
• sore throat, fever, or chills
• skin rash
• shortness of breath
• severe stomach pain
• severe headache
• seizures
• red skin, especially of the ears
• red or purple skin spots, from pinpoint sized dots to large bruises
• rapid heartbeat
• puffiness around the eyes, swelling of the eyelids, tongue, face, or lips
• problems with swallowing or breathing
• peeling, blistering, or flaking of the skin
• pale skin color
• painful or difficult urination
• pain in general
• nosebleed
• nausea or vomiting
• lower back or side pains
• light-colored stools
• joint inflammation
• itching, pain, redness, or swelling
• itching
• hoarseness or cough
• hives
• feeling of discomfort
• feeling generally tired or weak
• faintness, or lightheadedness when getting up quickly from a seated or prone position
• dizziness
• difficulty speaking
• deep, dark purple bruise
• dark urine
• confusion
• collection of blood under the skin
• chest pain
• changes in mental status
• blurred vision
• bloody or watery
• blood in urine or stools
• black, tarry stools
• back pain or backache
• aching muscle
• abdominal swelling or stomach cramps

Clopidogrel sometimes causes side effects that will resolve naturally without the need for further medical treatment, as your body gets used to the medication. There may also be ways to prevent and manage these effects, and your GP will give you more information on this. If you do find that these effects are particularly troublesome or persistent, check with your doctor.

The following side effects usually disappear after a week or so:

• sores, or welts
• soreness, redness, or itchy skin
• skin blisters
• pain in the side, stomach, or abdomen, sometimes radiating to the back
• noisy breathing
• muscle stiffness or pain
• loss of appetite
• joint pain
• inflammation or swelling in the mouth
• indigestion
• hives or welts
• headache
• hallucinations
• difficulty with moving
• diarrhea
• constipation
• change in taste
• bloating
• bad, or unpleasant aftertaste

This list is not necessary complete, and you may experience some effects that are not listed here. If you do experience any other effects, refer to your GP for advice.


You must take your prescribed dose of clopidogrel exactly as you have been instructed to by your treating specialist or GP. If you take more than the prescribed dose, the effectiveness of the drug will not increase, and you may become more likely to suffer from unwanted effects.

When you receive your prescription, you will be issued a patient information leaflet by your pharmacist. You must take time to read the information and instructions that the leaflet contains. If there is anything that you are not clear about, ask your GP.

Clopidogrel tablets may be taken when you are having a meal or just with water if you prefer. However, for the drug to work properly it is important that you swallow the tablets without crushing, chewing, sucking or biting them.

If you take an antacid, such as omeprazole, brand name Prilosec®, you should not use it while you are taking clopidogrel. Ask your GP to suggest another antacid drug that you could use instead.

If you have a health problem referred to as ‘acute coronary syndrome’ and you are taking clopidogrel to treat it, your GP may prescribe you aspirin as well.

The amount of this medication that you will be prescribed will not be the same as for everyone. You must follow the instructions on the dispensary label or those of your treating physician. The information given here is based solely on the average dose that is generally prescribed for this drug. If you have been given a different dose, do not alter it unless you are told to by your GP or treating specialist.

The level of dosage that you are given will depend on a number of different factors, including the potency of the preparation. The daily dosage rate, time you should allow between taking your tablets, and the duration of your course of treatment will also depend on your illness and why you have been given clopidogrel.

Clopidogrel tablets for the prevention of platelet clotting:

• Adults: take 75 mg once daily. Some patients will be told to use one 300 mg dose of medicine first. In addition, you may be told to use aspirin with this drug.

• Children: your treating physician will determine the appropriate dose and use.

If you forget to take your daily dose of clopidogrel, you should try to take it straight away. If your next tablet is nearly due, omit the one that you missed and revert to your usual dosing regimen. Do not take twice the amount of your prescribed dose.


Some drugs should not be used with clopidogrel. However, in some instances a variety of medications can be used at the same time, despite the risk of an interaction occurring. If this applies in your case, your GP might decide to alter the dose, or change the frequency of one or both of your drugs, or suggest ways in which you can manage any interactions that do occur.

Before you start your course of treatment with this drug, you must tell your doctor if you are already taking any of the drug that are listed below:

• Warfarin
• Vortioxetine
• Vilazodone
• Verapamil
• Venlafaxine
• Valdecoxib
• Tolmetin
• Tolfenamic Acid
• Tinzaparin
• Ticlopidine
• Tiaprofenic Acid
• Tenoxicam
• Sulindac
• Sodium Salicylate
• Sibutramine
• Sertraline
• Salsalate
• Salicylic Acid
• Rofecoxib
• Rivaroxaban
• Reviparin
• Repaglinide
• Rabeprazole
• Protein C
• Proquazone
• Propyphenazone
• Proglumetacin
• Piroxicam
• Piracetam
• Piketoprofen
• Phenylbutazone
• Phenprocoumon
• Phenindione
• Paroxetine
• Parnaparin
• Parecoxib
• Oxyphenbutazone
• Oxaprozin
• Omeprazole
• Nisoldipine
• Nimodipine
• Nimesulide Beta Cyclodextrin
• Nimesulide
• Niflumic Acid
• Nifedipine
• Nicardipine
• Nepafenac
• Nefazodone
• Naproxen
• Nadroparin
• Nabumetone
• Morniflumate
• Milnacipran
• Meloxicam
• Mefenamic Acid
• Meclofenamate
• Lumiracoxib
• Loxoprofen
• Lornoxicam
• Levomilnacipran
• Lepirudin
• Ketorolac
• Ketoprofen
• Ketoconazole
• Isradipine
• Indomethacin
• Ibuprofen
• Heparin
• Fondaparinux
• Fluvoxamine
• Flurbiprofen
• Fluoxetine
• Flufenamic Acid
• Fluconazole
• Floctafenine
• Feprazone
• Fepradinol
• Fenoprofen
• Felodipine
• Felbinac
• Felbamate
• Etravirine
• Etoricoxib
• Etofenamate
• Etodolac
• Esomeprazole
• Escitalopram
• Eptifibatide
• Enoxaparin
• Edoxaban
• Duloxetine
• Droxicam
• Dipyrone
• Dipyridamole
• Diltiazem
• Diflunisal
• Diclofenac
• Dexketoprofen
• Dexibuprofen
• Desvenlafaxine
• Desirudin
• Defibrotide
• Danaparoid
• Dalteparin
• Dabigatran Etexilate
• Clonixin
• Clevidipine
• Citalopram
• Cimetidine
• Cilostazol
• Choline Salicylate
• Certoparin
• Celecoxib
• Bupropion
• Bufexamac
• Bromfenac
• Bivalirudin
• Bemiparin
• Aspirin
• Argatroban
• Ardeparin
• Apixaban
• Anagrelide
• Amtolmetin Guacil
• Amlodipine
• Alteplase, Recombinant
• Alipogene Tiparvovec
• Acemetacin
• Aceclofenac

Using clopidogrel in addition to the brands listed below can present a much higher risk of some side effects. However, using both medicines could be the best option for you.

• Atorvastatin
• Vitamin A
• Simvastatin
• Phenytoin
• Lovastatin
• Ginkgo
• Fosphenytoin

It is not recommended that you eat certain food groups, use tobacco, or drink alcohol with some medications, as doing so can sometimes cause interactions to take place. Your doctor will advise you specifically on this aspect of your treatment with clopidogrel.


You must tell your doctor if you have ever suffered from an allergic reaction or become unwell when you have used this or any other medicines previously. In addition, you must mention any known allergies that you have to certain food groups, food dyes, preservative, or animal derivatives. This list should include non-prescription drugs, herbal remedies and teas, and vitamin or diet products or supplements.

It is not advisable to eat grapefruit or drink large amounts of grapefruit juice while you are using clopidogrel. Doing so could increase the risk of you suffering certain side effects.

Research has not shown that using clopidogrel presents any risk to the unborn baby. However, you should discuss the benefits and risks of using this medication in depth with your doctor if you are expecting a baby or if you are intending to become pregnant while you are undergoing treatment with this medicine.

It is not known if this medicine presents any risk to nursing infants or can be present in a mother’s breast milk. However, in the even that you are breastfeeding, you should discuss the risks of doing so while taking clopidogrel with your midwife or GP. You may prefer to use an alternative feeding option for your child until you have finished using this medication. Do not express breast milk for storage and later use.

Some existing and historical medical conditions can affect how this medication works. You must discuss in detail with your doctor any other medical conditions that you have suffered from.

Clopidogrel must not be used in patients who have a history of active bleeding, including head injury, peptic ulcers etc.

Clopidogrel is not recommended in patients who have a history of mini-cerebrovascular accident or transient ischemic attack, as these conditions could make the drug’s side effects worse.

While you are taking clopidogrel, you must attend your doctor for regular progress checks. These visits are very important in order to allow your GP to check that the medication is working as it should be and to determine the appropriate duration of your course of treatment. You will also need to have blood tests taken so that your doctor can check for any unwanted side effects.

Before you are given clopidogrel, you may be told that you need to undergo genetic testing. This medication may to prove to be as effective if you have CYP2C19 deficiency.

If you are due to attend for surgery or dental treatment, you must be sure to tell your treating physician or dentist. Clopidogrel increases the risk of severe bleeding in some patients. For this reason, you must not use the drug for a week or so before undergoing any form of invasive procedure. However, you should not suddenly stop taking the medicine without talking to your regular doctor first.

If you sustain any form of bleeding while you are taking clopidogrel, it may prove difficult to stop. For this reason, it is important to avoid playing sports or placing yourself in circumstances that could result in you becoming injured, sustaining cuts, or bruises. Take extra care when using razors, nail clippers, or other sharp objects. Avoid picking your nose and blow it gently if need be.

If any of the signs listed below in the bulleted list should manifest themselves, they could indicate that you are bleeding, and you should consult your doctor promptly:

• unusual bleeding
• black, tarry stools
• stools or urine with blood in them
• pinpoint red dots on the skin

Do not stop taking your prescribed dose of clopidogrel or change the amount you are taking, unless your doctor tells you to do so.

If you should happen to develop any of the things that are mentioned in the list of bullet points below, you should contact your doctor immediately. These signs can indicate that you have developed a very serious, rare health problem commonly referred to as, ‘thrombotic thrombocytopenic purpura’:

• weakness
• seizures
• problems speaking
• pinpoint red dots on your skin
• pale skin
• jaundice
• fever
• changes in your mental status
• bloody or dark urine

You should not take any other forms of medication, including items that you have picked up in your local pharmacy or drug store, such as cough and cold remedies, vitamin or herbal supplements while you are taking clopidogrel, unless you have first cleared it with your GP.


Your prescription of clopidogrel should be kept in a closed container and at room temperature. Do not place your tablets near to heat sources or leave them where they could be exposed to direct sunlight. Keep the tablets away from moisture.

Do not place the medicine in the fridge or freezer. Do not keep your tablets in your car where they could be exposed to extremes of temperature.

If the packaging appears damaged or opened, do not use the medicine; ask your pharmacist for a fresh supply.

Always put your tablets where they cannot be reached by children or pets. If a pet eats any of your clopidogrel tablets, seek veterinary advice immediately.

Dispose of any unwanted or out-of-date tablets carefully. Do not put them down the drains where they could cause environmental damage. Wrap the tablets in a sealed bag and put them into the bottom of your trash bin, where children and animals cannot get to them.


Clopidogrel is a drug that is classified as a platelet inhibitor. The medication works by preventing blood clots from forming, reducing the chance of a patient suffering a heart attack or a cerebrovascular accident. The medication is commonly used in combination with aspirin for patients who have a history of heart attack, severe chest pain, or cerebrovascular accident. Patients who have circulatory problems are also often given clopidogrel.

There are a number of pre-existing medical conditions where clopidogrel should not be used, as to do so could make these conditions worse or increase the side effects of the drug. In addition, there are a large number of drugs that should not be used together with clopidogrel tablets, as an interaction is likely to occur. For these reasons, it is very important that you fully appraise your doctor of any health conditions that you have and of any drugs that you are taking, before you start taking clopidogrel. You should also attend your scheduled check-up appointments to make sure that the drug is working correctly and that side effects are not causing problems.

Clopidogrel is designed to prevent the blood from clotting too easily. Although this is very effective in preventing serious illness such as heart attacks and cerebrovascular accident, it can present dangers for patients. You should avoid situations and activities where you might sustain cuts, bruises, or injury while you are taking clopidogrel tablets and for at least two weeks after your treatment program has finished.