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- What is clopidogrel, and how does it work (mechanism of action)?
- What are the uses 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 this drug?
What is clopidogrel, and how does it work (mechanism of action)?
Clopidogrel bisulfate (Plavix) 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 uses for clopidogrel?
Clopidogrel is used for preventing strokes, heart attacks, and death in individuals who have had a previous stroke, unstable angina, heart attack or have peripheral arterial disease (PAD). The combination of clopidogrel and aspirin is better than aspirin or clopidogrel alone in preventing another heart attack but the risk of bleeding is higher.
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.
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).
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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 this drug?
- Clopidogrel is avaialable as tablets: 75 and 300 mg. Tablets should be stored at room temperature, 15 C - 30 C (59 F - 86 F).
- Clopidogrel is available as a generic drug. You need a prescription from your doctor to obtain this medicine.
- Plavix is the brand name available for clopidogrel in the US.
Plavix (clopidogrel bisulfate) is an antiplatelet drug prescribed for the prevention of heart attacks and strokes in high risk individuals. Review side effects, drug interactions, warnings and precautions, and pregnancy information prior to taking this or any medication.
Multimedia: Slideshows, Images & Quizzes
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Related Disease Conditions
How the Heart Works: Sides, Chambers, and Function
The heart is a very important organ in the body. It is responsible for continuously pumping oxygen and nutrient-rich blood throughout your body to sustain life. It is a fist-sized muscle that beats (expands and contracts) 100,000 times per day, pumping a total of five or six quarts of blood each minute, or about 2,000 gallons per day.
Deep Vein Thrombosis (DVT, Blood Clot in the Legs)
Deep vein thrombosis (DVT) is a blood clot in the deep veins, and can be caused by broken bones, trauma to a limb, immobility, medications, smoking, cancer, genetic predisposition, and cancer. Symptoms of a deep vein thrombosis in a leg are swelling, tenderness, redness, warmth, and pain. Treatments for DVT include medications and surgery.
Blood Clots (in the Leg)
Blood clots can occur in the venous and arterial vascular system. Blood clots can form in the heart, legs, arteries, veins, bladder, urinary tract and uterus. Risk factors for causes of blood clots include high blood pressure and cholesterol, diabetes, smoking, and family history. Symptoms of a blood clot depend on the location of the clot. Some blood clots are a medical emergency. Blood clots are treated depending upon the cause of the clot. Blood clots can be prevented by lowering the risk factors for developing blood clots.
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: weakness, numbness, double vision or vision loss, confusion, vertigo, 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.
Internal 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.
Stroke vs. Mini-Stroke (TIA) Differences
A stroke or "brain attack" occurs when a blood clot or artery ruptures within the brain. The rupture or clot causes brain cell damage or death. A mini-stroke (TIA, transient ischemic attack) is caused by brain cells that dysfunctional over a short period. Stroke and mini-stroke warning signs of stroke and mini stroke are the same, and include, speech problems, weakness, numbness, and facial droop. Side effects of stroke may be permanent and you may never regain full function of the parts of the body affected. Mini-stroke side effects usually resolve within minutes to a couple of days. A transient ischemic attack (mini-stroke) is a precursor for stroke because 40% of individuals who have a mini-stroke will have a stroke within a year. Treatment of stroke depends upon the type and parts of the body affected.
Early Warning Signs and Symptoms of Stroke (FAST)
Stroke is a serious medical condition. If you think you or someone you know is having a stroke call 911 immediately. There are two main types of strokes, hemorrhagic and ischemic (the most common type). A hemorrhagic stroke occurs due to a blood vessel rupture in the brain. An ischemic stroke occurs when a blood clot becomes lodged in a blood vessel in the brain, which causes a loss of blood supply to the brain, possibly causing brain tissue death. FAST is an acronym that helps people identify stroke signs and symptoms so they can act fast and call 911. Face drooping, Arm weakness, and Speech difficulty are indicators that a person may be having a stroke and it is Time to seek emergency medical treatment. Additional signs and symptoms of stroke may include weakness, difficulty walking, blurred vision, dizziness, headache, confusion, difficulty speaking, and loss of sensation. Stroke is a major cause of death and disability in the U.S. Early identification and treatment of stroke helps reduce the risk of morbidity and mortality.
Pulmonary Embolism (Blood Clot in the Lung)
A pulmonary embolism (PE) occurs when a piece of a blood clot from deep vein thrombosis (DVT) breaks off and travels to an artery in the lung where it blocks the artery and damages the lung. The most common symptoms of a pulmonary embolism are shortness of breath, chest pain, and a rapid heart rate. Causes of pulmonary embolism include prolonged immobilization, certain medications, smoking, cancer, pregnancy, and surgery. Pulmonary embolism can cause death if not treated promptly.
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 legs or feet, and poor wound healing in the legs or feet. Treatment for peripheral artery disease include lifestyle measures, medication, angioplasty, and surgery.
Heart Attack (Myocardial Infarction)
A heart 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.
Intermittent 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.
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.
Atrial Fibrillation (AFib) Treatment Drugs
Atrial fibrillation (AFib) is a heart rhythm disorder that causes irregular and often rapid heartbeat. The medications to treat AFib include beta-blockers, blood thinners, and heart rhythm drugs. Atrial fibrillation drugs can cause serious side effects like seizures, vision changes, shortness of breath, fainting, other abnormal heart rhythms, excessive bleeding while coughing or vomiting, blood in the stool, and bleeding into the brain.
Migraine and Stroke
Migraine headache is a type of headache in which the exact cause is not known; however, they may be inherited, and certain foods and environmental factors can trigger and may contribute them. A stroke (brain attack) happens when a blood vessel in the brain leaks, bursts, or becomes blocked, which can be caused by many other health problems. Both migraines and strokes can can cause severe head pain (migraine pain usually is only on one side of the head). Migraine aura symptoms may mimic or feel like a stroke or mini-stroke (transient ischemic attack, TIA) because they have similar symptoms and signs like severe headache, numbness in the legs, feet, arms, hands, or face, nausea, vomiting, and dizziness. Other migraine aura symptoms include vision problems like flashing lights or blind spots in one eye. The main difference between migraine headache and stroke symptoms and signs is that a migraine headaches usually come on gradually while a stroke symptoms come on suddenly and unexpectedly.
Heart Attack vs. Heartburn
Heartburn is a symptom of another disease or medical problem and can be described as a feeling of burning in the chest accompanied by symptoms of nausea, vomiting, or a sour taste or food stuck in the back of the throat. Heart attack occurs when an artery in the heart is completely blocked by a blood clot, which causes that portion of heart muscle to die. Heart attack also has symptoms of chest pain, nausea, and vomiting, however, other warning signs and symptoms of a heart attack are unusual weakness or fatigue, and persistent and/or increased severity of symptoms over a few minutes. Heart attack is a life threatening emergency. If you think you or someone you are with is having a heart attack, call 911 immediately for urgent medical treatment. It may save your life.
Heart Attack vs. Stroke Symptoms, Differences, and Similarities
Heart attack usually is caused by a clot that stops blood flow supplying oxygen to an area of heart muscle, which results in heart muscle death. Stroke or "brain attack" is caused by a loss of blood supply to the brain (usually a blood clot) or by hemorrhagic stroke (bleeding within the brain), which results in brain tissue death. Both heart attack and stroke usually come on suddenly, produce similar symptoms, can be disabling, and can be fatal. The classic symptoms and warning signs of heart attack are different. Classic heart attack warning signs are chest pain or discomfort, shortness of breath, pain that radiates to the shoulders, back, arms, belly, jaw, or teeth, sweating, fainting, and nausea and vomiting. Moreover, woman having a heart attack may have additional symptoms like abdominal pain or discomfort, dizziness, clammy skin, and moderate to severe fatigue. The classic symptoms and warning signs that a person is having a stroke are confusion or loss of consciousness, sudden severe headache, speech problems, problems seeing out of one or both eyes, and numbness or weakness of only one side of the body. Moreover, a woman having a stroke may have additional warning symptom and signs like shortness of breath, disorientation, agitation, behavioral changes, weakness, nausea, vomiting, seizures, and hiccups. Recognition of stroke symptoms is vital for emergency treatment. The acronym "FAST" stands for recognition of Facial drooping, Arm weakness, Speech difficulty, and a Time for action. If you experience the symptoms heart attack or stroke (FAST) or see them develop in another person, then contact 911 immediately.
Carotid Artery Disease
The 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.
Heart Attacks in Women
Heart disease, particularly coronary artery disease is the leading cause of heart attacks. Women are more likely to die from a heart attack than men. High cholesterol, high blood pressure, obesity, and high triglycerides are contributors to heart disease. Some of the common symptoms of a heart attack in women include chest pain, shortness of breath, nausea, feeling faint or woozy, and more. Heart disease can be prevented by lifestyle changes and controlling high blood pressure, cholesterol, weight, and diseases such as diabetes.
Stroke vs Aneurysm (Differences and Similarities)
A stroke or "brain attack" is caused because blood flow to an area of the brain has been cut off by a blood clot or by a weakened or damaged blood vessel (for example, head trauma). The damaged area of the brain dies, which results in loss of function like speech capabilities, muscle movement, or muscles of an extremity like an arm or leg is reduced or lost completely. An aneurysm is a weakness in an artery wall. This weakness in the wall causes the artery to widen or balloon out, and then they rupture or break open. A person with an brain aneurysm generally won't have any symptoms until it becomes a problem. The symptoms and signs are similar to a stroke.Symptoms and signs of a stroke include: Vision problems Severe headache with no known cause Loss of memory Trouble getting words out Trouble typing, texting, or other coordination problems Both the American Heart Association and the American Stroke Association recommend using the FAST system to recognize and treat strokes. If you think someone may be having a stroke, remember FAST! F - Facial drooping A - Arm weakness S - Speech difficulty T - time - DO NOT DELAY. Call 911.If you think someone is having a stroke or aneurysm call 911 immediately. Both conditions require medical treatment. The prognosis for both diseases depend on the extent of the damage to the brain and any other affected areas of the body.
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 prevent or stop this damage to the heart muscle. Heart attack treatments included medications, procedures, and surgeries to protect the heart muscle against injury.
Heart Attack 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 Dizziness Fainting Leading a healthy lifestyle with a heart healthy low-fat diet, and exercise can help prevent heart disease and heart attack.
Stroke is the third leading killer in the United States. Some of the warning signs of stroke include sudden confusion, trouble seeing with one or both eyes, dizziness, loss of balance, and more. Stroke prevention and reatable risk factors for stroke include lowering high blood pressure, quit smoking, heart disease, diabetes control and prevention.
Treatment & Diagnosis
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Medications & Supplements
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- Drug Interactions
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- ticlopidine, Ticlid (discontinued brand in the US)
- cangrelor (Kengreal)
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Prevention & Wellness
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- Long-Term Use of Aspirin Plus Blood Thinner Is Safe: Study
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- Drug Combo May Reduce Risk of Second Stroke: Study
- Shopping Around Brings Steep Prescription Drug Savings, Report Finds
- New Drugs Might Give Heart Patients an Edge
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- Standard Dose of Blood Thinner May Not Be Best for All Patients
- Many Older Heart Attack Survivors Don't Stick With Meds
- Year of Taking Risky Blood Thinners May Be Unnecessary After Stent Surgery
- Adding Plavix to Aspirin Doesn't Help Guard Against Second Stroke: Study
- Daily Aspirin May Help Fight Prostate Cancer, But Not Breast Cancer
- New Blood Thinner Effient No Better Than Plavix at Preventing Heart Trouble: Study
- Guidelines Issued for New Blood Thinner Brilinta
- FDA Approves Generic Versions of Plavix
- Plavix's New Generic Status Could Be Boon for Patients
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- Low-Dose Daily Aspirin Enough to Help Heart Attack Patients: Study
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