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- What is clopidogrel, and how does it work (mechanism of action)?
- What brand names are available for clopidogrel?
- Is clopidogrel available as a generic drug?
- Do I need a prescription for clopidogrel?
- What are the side effects of clopidogrel?
- What is the dosage for clopidogrel?
- Which drugs or supplements interact with clopidogrel?
- Is clopidogrel safe to take if I'm pregnant or breastfeeding?
- What else should I know about clopidogrel?
What is clopidogrel, and how does it work (mechanism of action)?
Clopidogrel bisulfate is an anti-platelet drug, that is, a drug that inhibits the ability of platelets to clump together as part of a blood clot. Clopidogrel prevents blood clots by irreversibly binding to the P2Y12 receptor on platelets, preventing adenosine diphosphate (ADP) from activating platelets. It belongs to a class of drugs called P2Y12 inhibitors. Other drugs in this class include ticagrelor (Brilinta) and prasugrel (Effient). Clopidogrel is similar to ticlopidine (Ticlid) in chemical structure and in the way it works. Unlike ticlopidine, clopidogrel bisulfate does not cause serious reductions of white cells in the blood and, therefore, routine blood testing to determine if the white blood cell count is low is not necessary during treatment. The risk of heart attacks and strokes (which usually are caused by blood clots) is increased in patients with a recent history of stroke or heart attack, and patients with peripheral vascular disease. (Peripheral vascular disease is the same as atherosclerotic arterial disease or "hardening" of the arteries in which the arteries become narrowed. It frequently occurs in the legs and often causes claudication or pain in the legs upon walking.) Clopidogrel bisulfate is used to reduce the risk of heart attacks and strokes in these patients. Clopidogrel bisulfate was approved by the FDA in 1997.
What are the side effects of clopidogrel?
The tolerability of clopidogrel is similar to that of aspirin. The more common side effects of clopidogrel are:
- Abdominal pain
- chest pain,
- muscle aches,
- severe bleeding,
- allergic reactions,
- pancreatitis, and
- liver failure.
Ticlopidine (Ticlid) is an antiplatelet medication quite similar to clopidogrel. It has been associated with a severe reduction in white blood cell count in between 0.8% and 1% of persons. The risk of this dangerous side effect with clopidogrel is about 0.04%, much less than with ticlopidine but twice that of aspirin.
Clopidogrel rarely causes a condition called thrombotic thrombocytopenic purpura (TTP) in one out of every 250,000 people. TTP is a serious condition in which blood clots form throughout the body. Blood platelets, which participate in clotting, are consumed, and the result can be bleeding because enough platelets are no longer left to allow blood to clot normally. For comparison, the related drug, ticlodipine (Ticlid), causes TTP 17-50 times more frequently than clopidogrel.
Quick GuideHeart Disease: Symptoms, Signs, and Causes
What is the dosage for clopidogrel?
Clopidogrel bisulfate usually is taken once daily. It can be taken with or without food. Clopidogrel is activated by enzymes in the liver to its active form. Individuals who have reduced activity of liver enzymes that activate clopidogrel due to liver disease may not adequately respond to clopidogrel. Alternative treatments should be used for these patients. The recommended dose for treating unstable angina or heart attack is 300 mg initially followed by 75 mg daily in combination with 75-325 mg of aspirin. Peripheral arterial disease or recent stroke is treated with 75 mg daily.
Which drugs or supplements interact with clopidogrel?
The combination of clopidogrel with nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil, Nuprin), naproxen (Naprosyn, Aleve), diclofenac (Voltaren), etodolac (Lodine), nabumetone (Relafen), fenoprofen (Nalfon), flurbiprofen (Ansaid), indomethacin (Indocin), ketoprofen (Orudis; Oruvail), oxaprozin (Daypro), piroxicam (Feldene), sulindac (Clinoril), tolmetin (Tolectin), and mefenamic acid (Ponstel) may increase the risk of stomach and intestinal bleeding.
Clopidogrel is converted to its active form by enzymes in the liver. Drugs that reduce the activity of these enzymes, for example, omeprazole (Prilosec, Zegerid) or esomeprazole (Nexium) may reduce the activity of clopidogrel and should not be used with clopidogrel. Other drugs that also may react with clopidogrel in a similar fashion include fluoxetine (Prozac, Sarafem), cimetidine (Tagamet), fluconazole (Diflucan), ketoconazole (Nizoral, Extina, Xolegel, Kuric), voriconazole (Vfend), ethaverine (Ethatab, Ethavex), felbamate (Felbatol), and fluvoxamine (Luvox).
Is clopidogrel safe to take if I'm pregnant or breastfeeding?
There are no adequate studies of clopidogrel in pregnant women.
Studies in rats have shown that clopidogrel appears in breast milk; however, it is not known whether it also appears in human breast milk. Because of a potential for side effects in the nursing infant, the physician must weigh the potential benefits and possible risks before prescribing clopidogrel to nursing mothers.
What else should I know about clopidogrel?
What preparations of clopidogrel are available?
Tablets: 75 and 300 mg.
How should I keep clopidogrel stored?
Tablets should be stored at room temperature, 15 C - 30 C (59 F - 86 F).
Reference: FDA Prescribing Information
Quick GuideHeart Disease: Symptoms, Signs, and Causes
Clopidogrel bisulfate (Plavix) is an antiplatelet drug prescribed for the prevention of heart attacks and strokes in high risk individuals. Side effects, drug interactions, warnings and precautions, and pregnancy information should be reviewed prior to taking any medication.
Multimedia: Slideshows, Images & Quizzes
High Blood Pressure (Hypertension) Quiz: Symptoms, Signs & Causes
Take this quiz and test your IQ of high blood pressure (hypertension), the cardiovascular disease that causes most strokes and...
Picture of Peripheral Vascular Disease
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Related Disease Conditions
Stroke (Signs, Symptoms, Warning Signs)
A stroke is an interruption of the blood supply to part of the brain caused by either a blood clot (ischemic) or bleeding...
Peripheral Vascular Disease
Peripheral vascular disease (PVD) refers to diseases of the blood vessels (arteries and veins) located outside the heart and...
Internal bleeding occurs when an artery or vein is damaged and blood to escapes the circulatory system and collects inside the...
Intermittent claudication, or pain and cramping in the lower leg is caused by inadequate blood flow to the leg muscles. This lack...
Heart attack happens when a blood clot completely obstructs a coronary artery supplying blood to the heart muscle. A heart attack...
Transient Ischemic Attack (TIA, Mini-Stroke)
When a portion of the brain loses blood supply, through a blood clot or embolus, a transient ischemic attack (TIA, mini-stroke)...
Carotid Artery Disease
The term carotid artery disease refers to the narrowing of the carotid arteries and can also be called carotid stenosis. Fatty...
Heart Attack Treatment
A heart attack involves damage or death of part of the heart muscle due to a blood clot. The aim of heart attack treatment is to...
Heart Attack Prevention
Heart disease and heart attacks can be prevented by leading a healthy lifestyle with diet, exercise, and stress management....
Treatment & Diagnosis
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Top clopidogrel Related ArticlesComplete List
Aspirin and Antiplatelet Medications
Aspirin belongs to a drug class called NSAIDs (nonsteroidal anti-inflammatory drugs), and has an important inhibitory effect on platelets in the blood. Platelets are needed in order for blood clots to form. Because aspirin inhibits blood clotting, it is used to reduce the risk of recurrent stroke and near-stroke (transient ischemic attack). Aspirin therapy is used to prevent heart attacks and treat heart attacks. Common side effects of aspirin include:
- Easy bruising
- Ringing in the ears
The U.S. Preventive Services Task Force has recommendations and guidelines for the use of aspirin therapy and heart disease prevention. Aspirin therapy is used for the treatment and prevention of:
- Heart attacks
Cangrelor (Kengreal) is a drug used to reduce the risk of heart attacks during precutaneious coronary intervention, repeat coronary revascularization, and stent thrombosis. Side effects include
- Shortness of breath
- Allergic reactions
Drug interactions, dosage, and pregnancy and breastfeeding safety should be reviewed prior to taking this medication.
Carotid Artery DiseaseThe term carotid artery disease refers to the narrowing of the carotid arteries and can also be called carotid stenosis. Fatty substance buildup and cholesterol deposits, called plaque are the cause of the narrowing arteries. Carotid artery disease can be treated by following recommended lifestyle changes, taking prescription medications, and considering a procedure to improve blood flow, if your doctor believes it could help.
ClaudicationIntermittent claudication, or pain and cramping in the lower leg is caused by inadequate blood flow to the leg muscles. This lack of blood flow causes a decrease in oxygen delivered to the muscles of the legs. Claudication is generally felt when walking and decreases with rest. In severe cases, claudication may be felt at rest. Narrowing of arteries cause claudication. Treatment includes exercise, medication, and in some cases surgery.
Drug InteractionsDrug interactions occur frequently. Get facts about the types of drug interactions, what substances or other things that may interact with drugs such as OTC drug and prescription drugs, vitamins, food(s) (grapefruit), and laboratory tests. Find out how to protect yourself from potential drug interactions.
Drugs: What You Should Know About Your DrugsImportant information about your drugs should be reviewed prior to taking any prescription drug. Side effects, drug interactions, warnings and precauctions, dosage, what the drug is used for, what to do if you miss a dose, how the drug is to be stored, and generic vs. brand names.
Heart AttackHeart attack happens when a blood clot completely obstructs a coronary artery supplying blood to the heart muscle. A heart attack can cause chest pain, heart failure, and electrical instability of the heart.
Heart Attack and Atherosclerosis Prevention
Heart disease and heart attacks can be prevented by leading a healthy lifestyle with diet, exercise, and stress management. Symptoms of heart attack in men and women include chest discomfort and pain in the shoulder, neck, jaw, stomach, or back. Women experience the same symptoms as men; however, they also may experience:
- Extreme fatigue
- Pain in the upper abdomen
Leading a healthy lifestyle with a heart healthy low-fat diet, and exercise can help prevent heart disease and heart attack.
Heart Attack TreatmentA heart attack involves damage or death of part of the heart muscle due to a blood clot. The aim of heart attack treatment is to prevent or stop this damage to the heart muscle. Heart attack treatments included medications, procedures, and surgeries to protect the heart muscle against injury.
Take the HBP QuizTake this quiz and test your IQ of high blood pressure (hypertension), the cardiovascular disease that causes most strokes and heart attacks. How are dizziness, snoring, and gout related to HBP? Find the answer and learn how medical treatments and lifestyle adjustments fight this common problem.
Internal BleedingInternal bleeding occurs when an artery or vein is damaged and blood to escapes the circulatory system and collects inside the body. Internal bleeding can be caused by a variety of situations such as blunt trauma, deceleration trauma, medications, fractures, and spontaneous bleeding. Treatment of internal bleeding depends on the cause of the bleeding.
Peripheral Vascular Disease
Peripheral vascular disease (PVD) refers to diseases of the blood vessels (arteries and veins) located outside the heart and brain. While there are many causes of peripheral vascular disease, doctors commonly use the term peripheral vascular disease to refer to peripheral artery disease (peripheral arterial disease, PAD), a condition that develops when the arteries that supply blood to the internal organs, arms, and legs become completely or partially blocked as a result of atherosclerosis. Peripheral artery disease symptoms include:
- Intermittent Leg pain while walking
- Leg pain at rest
- Numbness in the
Treatment for peripheral artery disease includes: lifestyle measures, medication, angioplasty, and surgery.
Peripheral Vascular Disease PictureDiabetes also affects the blood vessels and alters the flow of blood. See a picture of Peripheral Vascular Disease and learn more about the health topic.
Stroke Symptoms and Treatment
A stroke is an interruption of the blood supply to part of the brain caused by either a blood clot (ischemic) or bleeding (hemorrhagic). Symptoms of a stroke may include
- double vision or vision loss,
- vertigo, and
- difficulty speaking or understanding speech.
A physical exam, imaging tests, neurological exam, and blood tests may be used to diagnose a stroke. Treatment may include administration of clot-busting drugs, supportive care, and in some instances, neurosurgery. The risk of stroke can be reduced by controlling high blood pressure, high cholesterol, diabetes, and stopping smoking.
ticlopidineTiclopidine (Ticlid [discontinued brand in the US]) is a medication prescribed for preventing strokes or TIAs (mini-strokes), preventing blood clots in stents placed in the heart. Off-label uses include prevention of heart attacks in individuals with unstable angina, or experienced previous heart attacks, combination with aspirin for preventing blood clots in stents, and intermittent claudication. Side effects, drug interactions, warnings and precautions, and patient information should be reviewed prior to taking any medication.
Transient Ischemic Attack (TIA, Mini-Stroke)When a portion of the brain loses blood supply, through a blood clot or embolus, a transient ischemic attack (TIA, mini-stroke) may occur. If the symptoms do not resolve, a stroke most likely has occurred. Symptoms of TIA include: confusion, weakness, lethargy, and loss of function to one side of the body. Risk factors for TIA include vascular disease, smoking, high blood pressure, high cholesterol, and diabetes. Treatment depends upon the severity of the TIA, and whether it resolves.