The effectiveness of clopidogrel hydrogen sulfate results from its antiplatelet activity, which is dependent on its conversion to an active metabolite by the cytochrome P450 (CYP) system, principally CYP2C19. Clopidogrel hydrogen sulfate at recommended doses forms less of the active metabolite and so has a reduced effect on platelet activity in patients who are homozygous for nonfunctional alleles of the CYP2C19 gene, (termed “CYP2C19 poor metabolizers”). Tests are available to identify patients who are CYP2C19 poor metabolizers. Consider use of another platelet P2Y12 inhibitor in patients identified as CYP2C19 poor metabolizers ..
Medically reviewed by Drugs.com. Last updated on April 24, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Platelet Aggregation Inhibitor
Pharmacologic Class: ADP-Induced Aggregation Inhibitor
Uses for Plavix
Clopidogrel is used alone or together with aspirin to lessen the chance of a heart attack or stroke. It is given to patients who have already had a heart attack, severe chest pain, or a stroke, or to patients with other circulation problems that could cause a stroke or heart attack.
A heart attack or stroke may occur when a blood vessel is blocked by a blood clot. Clopidogrel is a platelet inhibitor. It reduces the chance that a harmful blood clot will form by preventing platelets from clumping together in the blood. Clopidogrel may also increase the chance of serious bleeding in some people.
This medicine is available only with your doctor's prescription.
Before using Plavix
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of clopidogrel in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of clopidogrel in the elderly.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Alipogene Tiparvovec
- Alteplase, Recombinant
- Amtolmetin Guacil
- Choline Salicylate
- Dabigatran Etexilate
- Flufenamic Acid
- Mefenamic Acid
- Morphine Sulfate Liposome
- Niflumic Acid
- Nimesulide Beta Cyclodextrin
- Opium Alkaloids
- Protein C
- Salicylic Acid
- Sodium Salicylate
- Tiaprofenic Acid
- Tolfenamic Acid
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Vitamin A
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco.
- Grapefruit Juice
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Bleeding, active (eg, peptic ulcers, head injury)—Should not be used in patients with this condition.
- Stroke, recent or
- Transient ischemic attack (TIA or mini-stroke), recent—May cause side effects to become worse.
Proper use of Plavix
Take this medicine exactly as directed by your doctor. Clopidogrel will not work properly if you take less of it than directed. Taking more clopidogrel than directed may increase the chance of serious side effects without increasing the helpful effects.
This medicine comes with a Medication Guide. It is very important that you read and understand this information. Be sure to ask your doctor about anything you do not understand.
You may take this medicine with or without food.
If you are also taking omeprazole (Prilosec®), do not use it at the same time that you take this medicine. Talk with your doctor about using a different antacid.
If you are using this medicine for a condition called acute coronary syndrome, your doctor may tell you to take aspirin while you are using clopidogrel. In this case, do not change the dose or stop taking the aspirin without talking to your doctor first.
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For prevention of blood clots:
- Adults—75 milligrams (mg) once a day. In some patients, a single dose of 300 mg is given first. Your doctor may also give you aspirin together with this medicine.
- Children—Use and dose must be determined by your doctor.
- For prevention of blood clots:
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Precautions while using Plavix
It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood tests may be needed to check for unwanted effects.
Your doctor may do a genetic test before prescribing this medicine to determine if you have a deficiency in a liver enzyme called CYP2C19. This medicine may not work as well if you have this condition.
Tell all medical doctors, dentists, nurses, and pharmacists you go to that you are taking this medicine. Clopidogrel may increase the risk of serious bleeding during a surgery, other medical procedures (e.g., coronary stent procedure), or some kinds of dental work. You may need to stop using this medicine at least 5 days before a surgery, medical procedure, or dental work. Do not stop taking your medicine without your doctor's permission.
While you are using this medicine, if you have any kind of bleeding, it may take longer than usual to stop, especially if you hurt yourself. Stay away from rough sports or other situations where you could be bruised, cut, or injured. Be careful when using sharp objects, including razors and fingernail clippers.
This medicine may increase your chance of bleeding or bruising. Check with your doctor right away if you notice any unusual bleeding or bruising; black, tarry stools; blood in the urine or stools; or pinpoint red spots on your skin. Avoid picking your nose. If you need to blow your nose, blow it gently.
Do not change your dose or stop taking this medicine without checking first with your doctor.
Check with your doctor right away if you have the following symptoms: change in mental status, dark or bloody urine, difficulty with speaking, fever, pale color of the skin, pinpoint red spots on the skin, seizures, weakness, yellow eyes or skin. These maybe symptoms of a rare and serious condition called thrombotic thrombocytopenic purpura (TTP).
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Plavix side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Chest pain
- collection of blood under the skin
- deep, dark purple bruise
- itching, pain, redness, or swelling
- pain in general
- red or purple spots on the skin, varying in size from pinpoint to large bruises
- painful or difficult urination
- shortness of breath
- vomiting of blood or material that looks like coffee grounds
- Black, tarry stools
- blistering, flaking, or peeling of the skin
- blood in the urine or stools
- fever, chills, or sore throat
- headache (sudden, severe)
- nausea or vomiting
- stomach pain (severe)
- ulcers, sores, or white spots in the mouth
- unusual bleeding or bruising
- weakness (sudden)
Incidence not known
- Abdominal or stomach cramps or swelling
- back pain or backaches
- blurred vision
- change in mental status
- cough or hoarseness
- dark urine
- difficulty with breathing or swallowing
- difficulty with speaking
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- fast heartbeat
- feeling of discomfort
- general feeling of tiredness or weakness
- inflammation of the joints
- light-colored stools
- lower back or side pain
- muscle aches
- pale color of the skin
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
- reddening of the skin, especially around the ears
- swelling of the eyes, face, or inside of the nose
- swollen lymph glands
- swollen or painful glands
- tightness in the chest
- unusual tiredness or weakness
- upper right abdominal or stomach pain
- watery or bloody diarrhea
- yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Incidence not known
- Bad, unusual, or unpleasant (after) taste
- change in taste
- difficulty with moving
- hives or welts
- loss of appetite
- muscle pain or stiffness
- noisy breathing
- pain in the joints
- pains in the stomach, side, or abdomen, possibly radiating to the back
- redness, soreness, or itching skin
- seeing, hearing, or feeling things that are not there
- skin blisters
- sores, welting, or blisters
- swelling or inflammation of the mouth
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
- How long does Plavix stay in the body once I stop taking it. How much Plavix is too much?
- Brilinta vs Plavix: what's the difference?
- Is ticagrelor better than clopidogrel?
More about Plavix (clopidogrel)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Patient Tips
- Drug Images
- Drug Interactions
- Compare Alternatives
- Support Group
- Pricing & Coupons
- En Español
- 55 Reviews
- Generic Availability
- Drug class: platelet aggregation inhibitors
Related treatment guides
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