Plavix (clopidogrel) can cause side effects that range from mild to serious. More common side effects include bruising, bleeding, and itching. If side effects from Plavix become difficult to tolerate, talk with your doctor.

Plavix is used to lower the risk of heart attack and stroke in adults who:

Keep reading to learn about the common, mild, and serious side effects Plavix can cause. To learn more about Plavix, including its uses, dosage, and cost, read this Plavix overview.

Plavix has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Tips for managing side effects” section.

Plavix can cause certain side effects, some more common than others. These side effects may be temporary, lasting a few days to weeks. Talk with your doctor if side effects do not go away, worsen, or become too difficult to tolerate.

Plavix’s commonly reported side effects include:

Mild side effects have been reported with Plavix. These include:

* To learn more about this side effect, see the “Tips for managing side effects” section.

Usually, these side effects are temporary. And some may be easily manageable. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop taking Plavix unless your doctor recommends it.

Plavix may cause mild side effects other than those already mentioned. See the drug’s prescribing information for details.

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Plavix may cause serious side effects. The following list may not include all possible serious side effects of the drug. For more information, you can refer to Plavix’s prescribing information.

If you develop serious side effects while taking Plavix, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported include:

For more information about some of these side effects, see the “Tips for managing side effects” section.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. Sharing your experience helps make medication safer for everyone by giving doctors and researchers more information about how the drug works in real life. If you develop a side effect while taking Plavix and want to tell the FDA about it, visit MedWatch or call 800-FDA-1088.

Allergic reaction

For some people, Plavix can cause an allergic reaction. But this side effect wasn’t reported in the drug’s studies.

In general, symptoms of an allergic reaction can be mild or serious.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking Plavix.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Plavix, they may have you switch to a different treatment.

While taking Plavix, you may be able to take steps to make side effects easier to manage.

Boxed warning: Drug metabolism problem

Plavix has a boxed warning for a drug metabolism problem. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

Plavix is metabolized (broken down) in the liver by an enzyme called CYP2C19. The effectiveness of Plavix depends on how well this enzyme can break it down into a more active compound. If CYP2C19 can’t sufficiently metabolize the drug, Plavix will be less effective in treating your condition.

What might help

Before you start Plavix, your doctor will check whether you have the CYP2C19 enzyme. If you don’t, they’ll suggest other treatments that will work better for your condition.

Severe bleeding

Plavix works by preventing your blood from clotting as it usually would. This can increase your risk of bruising or bleeding, which may be serious. Rarely, Plavix can cause severe, life threatening bleeding that requires immediate medical attention. For this reason, Plavix is not recommended for people with active bleeding, such as from a peptic ulcer or bleeding in the brain.

Symptoms of severe bleeding can include:

  • red or black stools
  • blood in urine
  • unexplained bruising
  • coughing up blood, such as coffee ground vomitus
  • unexplained severe bleeding that lasts a long time

What might help

If you experience bruising or bleeding with Plavix, call your doctor. They’ll determine the cause and whether to treat it. They’ll discuss the risks and benefits of continuing Plavix versus switching to a different treatment for your condition.

Do not stop Plavix without talking with your doctor first. Stopping this drug can increase your risk of a heart attack or stroke.

Thrombotic thrombocytopenic purpura (TTP)

Taking Plavix can cause a serious side effect called thrombotic thrombocytopenic purpura (TTP). This was a rare side effect reported in studies of the drug. This condition causes small blood clots to form throughout your body, including in your blood vessels. This can cause severe or life threatening medical complications.

With TTP, you have bruising or purple or red spots that look like a skin rash. Symptoms of TTP include:

What might help

If you have symptoms of TTP, such as skin rash, call your doctor right away. They’ll order tests to determine whether you have TTP and treat it if you do. For a severe reaction, they’ll likely have you stop Plavix permanently and switch you to a medication that’s safer for you.

Nosebleeds

People taking Plavix may experience nosebleeds. This was reported in studies of the drug. Plavix prevents your blood from clotting, so you could have bleeding that doesn’t stop easily.

What might help

If you experience a mild nosebleed with Plavix, sit upright, lean forward, and pinch the bridge of your nose (under the bony area) for about 10 minutes.

If bleeding is severe or doesn’t stop after 15 minutes, call your doctor or seek medical help.

Get answers to some frequently asked questions about side effects of Plavix.

Can Plavix cause different side effects in older adults?

It’s possible. How your body reacts to treatment with Plavix depends on your circumstances. Certain factors can increase your risk of side effects from this drug, including your overall health, your age, and other medications you take.

The maker of Plavix has not recommended any dosage adjustments when the drug is used in older adults (people ages 65 years and over).

Your doctor will decide the best Plavix dosage for you based on your overall health and the condition you’re taking the drug to treat. They’ll talk with you about possible side effects, including the risk of severe bleeding. Ask them for more information if you’re concerned about certain side effects based on your age.

If I stop taking Plavix 75 mg, will I experience certain side effects?

Yes, it’s possible. Stopping Plavix can increase your risk of heart-related problems. It’s important to take this drug exactly as your doctor recommends. Do not stop taking Plavix without asking them first.

If you’re scheduled for certain kinds of surgery, your doctor may have you temporarily stop Plavix. They may also have you stop taking it if you have active bleeding. They’ll have you restart the drug as soon as it’s safe to do so.

If you experience severe bleeding or other serious side effects, tell your doctor. They’ll decide whether you should stop Plavix. If needed, they’ll switch you to a different drug.

If you think you’re experiencing a life threatening medical emergency, such as severe bleeding that won’t stop, call 911 or a local emergency number right away.

Does Plavix cause fatigue?

Fatigue wasn’t reported in studies of Plavix. But it’s a symptom of some heart conditions, such as stroke and heart attack. Plavix can be used to help prevent these conditions from reoccurring in people who’ve already experienced them. Plavix is also prescribed to lower the risk of certain other heart conditions, such as acute coronary syndrome, which can also cause fatigue.

Certain side effects of Plavix, such as bleeding and thrombotic thrombocytopenic purpura (TTP), can also cause fatigue. If you have fatigue that bothers you, call your doctor. They’ll try to determine the cause and suggest ways to help manage it. If you have severe fatigue, they may recommend switching you to a medication that’s safer for you.

Consider the following important information before starting Plavix.

Boxed warning

Plavix has a boxed warning. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). For details, see the “Tips for managing side effects” section.

Other precautions

Bleeding disorder: If you have a bleeding disorder such as hemophilia, Plavix may not be safe for you. This is because Plavix prevents your blood from clotting as it usually would, which can increase your risk of severe bleeding. Tell your doctor if you have a bleeding disorder. They’ll discuss the benefits and risks of Plavix with you and may recommend a different treatment for your condition.

Active bleeding: Do not take Plavix if you have active bleeding, such as from a peptic ulcer or bleeding in the head. Because it prevents your blood from clotting as it normally would, Plavix could increase your risk of severe, uncontrolled bleeding.

Allergic reaction: If you’ve had an allergic reaction to Plavix or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other medications that might be better options.

Surgery: If you’re scheduled to have surgery (including dental surgery) while taking Plavix, tell your doctor. They may recommend that you stop taking the drug a few days before your surgery. This is to lower the risk of severe bleeding from Plavix. They’ll discuss your risks and when to stop taking the drug, as well as when it’s safe to start it again after surgery.

Tell all of your doctors about all of the drugs you’re taking. This includes over-the-counter products, as some of these may increase your risk of serious side effects with Plavix.

Kidney disease: If you have moderate to severe kidney disease, it is unknown whether Plavix would work well for you. Tell your doctor about any kidney problems you may have. They’ll be able to tell you more about the risks and benefits of Plavix for you.

Ulcers: If you’ve had or currently have ulcers in your stomach or intestines, taking Plavix may increase your risk of bleeding in your gastrointestinal (GI) tract. Tell your doctor about any problems you’ve had or currently have with GI ulcers before starting Plavix.

Alcohol and Plavix

There are no known interactions between Plavix and alcohol. But drinking too much alcohol with Plavix could increase your risk of bleeding. If you plan to consume alcohol while taking this drug, ask your doctor how much is safe.

Pregnancy and breastfeeding while taking Plavix

There have been no reports of harm to a fetus in studies of clopidogrel* use during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor about the benefits and risks of taking Plavix during pregnancy. They can provide more information based on your individual situation.

If you’re taking Plavix during pregnancy, your doctor may suggest stopping it 5 to 7 days before your delivery date. This will lower your risk of serious bleeding during and after delivery.

It is unknown whether Plavix passes into breast milk. If you’re taking Plavix, talk with your doctor about the safety of breastfeeding. They may recommend other ways to feed your child while you’re taking this drug or suggest a different medication for you.

* Clopidogrel is the active ingredient in Plavix. An active ingredient is what makes a medication work.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.