Plavix side effects and how to avoid them

Plavix side effects include bruising, itching, and diarrhea; however, more serious side effects like bleeding may occur. Learn when to seek medical attention for side effects.

By Irene Xue, Pharm.D. | Oct. 26, 2021

Plavix is the brand name for a drug called clopidogrel. Plavix belongs to a class of medications called antiplatelet drugs that prevent the formation of blood clots. Antiplatelet drugs work by preventing platelets—or blood cells—from sticking together to form a clot that blocks an artery. Over time, the narrowing of arteries can lead to heart diseases like acute coronary syndrome.

You may be prescribed Plavix if you have unstable angina (chest pain) due to heart problems, peripheral arterial disease, or if you have had a heart attack or ischemic stroke. Plavix can be used alone or with aspirin to prevent blood clotting and lower the risk of having a future heart attack or stroke. Plavix is available as a 300 mg and 75 mg tablet, and the usual dose is 75 mg taken once a day.

Like other antiplatelet drugs, Plavix can cause potentially serious side effects, interact with other medications, and may not be suitable for individuals with certain medical conditions. However, there are ways to minimize or avoid these problems.

Common side effects of Plavix

The most common side effects of Plavix are:

Nosebleeds
Bruises
Bleeding that takes longer to stop
Itching
Diarrhea
Stomach pain
Indigestion

Bruising

Bruising is one of the most common side effects of Plavix. Bruises form when small blood vessels under the skin break, leading to localized bleeding. Because Plavix works by thinning the blood, you might experience bruising more easily and often while taking this medication. Other signs of minor bleeding such as prolonged nosebleeds, bleeding gums, heavy periods, and cuts that take longer to stop bleeding may also occur.

In clinical trials, these side effects went away after the first few months of therapy. Individuals should speak with their healthcare provider and seek medical attention if they have bruises that are very large, happen without a known cause, or that last a long time.

Serious side effects of Plavix

Serious side effects of Plavix happen rarely but can occur. Tell your healthcare provider if you have any of the following serious side effects or if you have any side effect that bothers you or doesn’t go away. The most serious side effects of Plavix are:

Pink, red, or brown urine
Red or black, tarry stools
Coughing up or vomiting blood that looks like coffee grounds
Unusual or unexpected bruises or bleeding
Stomach ulcers
Thrombotic thrombocytopenic purpura
Low white blood cell count
Aplastic anemia
Allergic reaction (hives, swelling of the face or hands, chest tightness, shortness of breath)
Redness, rash, peeling, and inflammation of the skin
Stevens-Johnson syndrome
Yellowing of the skin or eyes, indicating liver problems
Joint or muscle pain
Severe stomach pain
Dizziness and low blood pressure
Loss of taste

Thrombotic thrombocytopenic purpura

Thrombotic thrombocytopenic purpura (TTP) is a condition that causes small blood clots to form in blood vessels throughout the body, blocking blood flow to vital organs. TTP occurs in one out of 8,500 to 26,000 people who use Plavix, and symptoms usually appear within the first two weeks of medication use. Although it has a low incidence, TTP is a life-threatening condition that requires immediate medical attention. Get medical help right away if you notice any of the following TTP symptoms when starting Plavix therapy:

Red or purple spots on the skin or in the mouth
Yellowing of the skin or eyes
Weakness
Pale skin
Fever
Fast heart rate or shortness of breath
Headache, confusion, or speech changes
Low amount of urine or having blood or protein in the urine

Tiredness

Plavix may cause symptoms of tiredness or weakness for multiple reasons. Plavix increases the risk of bleeding, and individuals may feel more tired than usual if blood loss occurs. High levels of blood loss can also lead to low blood pressure, which also causes weakness, dizziness, and fatigue. Tiredness may also be a sign of the potentially fatal condition TTP. Individuals that have excessive tiredness or any other symptoms of TTP while taking Plavix should consult their healthcare provider.

Weight loss

Weight changes, including weight loss, are not commonly seen with Plavix. However, Plavix has been shown to cause loss of taste in a few individuals within the first two to eight weeks of taking the medication. Patients who lose their sense of taste may also have decreased appetite, leading to weight loss. It’s not known why Plavix causes loss of taste, but this side effect should go away after stopping the medication.

Plavix side effects in the elderly

Plavix is generally safe and effective in older adults, and there are no restrictions for its use in this population. However, seniors have a higher risk of bleeding from Plavix due to factors such as being frail, being at risk for falls, and having multiple comorbidities like diabetes, high blood pressure, and liver or kidney problems.

In a clinical trial of 730 patients older than 74 years old who used Plavix for one year, 2.7% of patients had major bleeding. In addition, older individuals are especially at risk for upper gastrointestinal bleeding while taking Plavix and should be closely monitored for signs of dark, tarry stools or vomiting blood.

How long do Plavix side effects last?

Plavix has a short half-life of six hours, meaning that most of the drug is cleared from the body within 24 hours. It takes longer for platelet function to return to normal. After stopping Plavix, platelet levels recover in about a week, and most side effects should also fade by then after the medication is discontinued.

Some individuals will need to take Plavix long-term. Bleeding, the most common side effect, tends to occur in the first few months of therapy and goes away afterward as the body adjusts to the medication.

Serious side effects such as TTP, allergic reactions, severe bleeding, and liver problems require immediate medical attention because they can cause permanent complications.

Plavix contraindications and warnings

Some people may not be able to take Plavix because of pre-existing health conditions that affect its safety and effectiveness.

Abuse and dependence

Plavix is not addictive or habit-forming, and there are no withdrawal symptoms associated with discontinuing Plavix.

Overdose

Up to 600 mg of Plavix can be given as a single loading dose, and the usual daily dose is 75 mg. Plavix has an irreversible effect on platelets that lasts for the entire lifespan of the platelet (8-10 days), so an overdose of Plavix may result in fatal bleeding complications. Other signs of Plavix overdose include vomiting and difficulty breathing. Any known or suspected overdose of Plavix requires emergency treatment.

Restrictions

Plavix has contraindications for use, meaning that it cannot be given to individuals with certain conditions. Plavix is contraindicated in the following populations:

Individuals with active bleeding such as a peptic ulcer or brain bleed
Those with a known hypersensitivity to Plavix or any component of the drug

Plavix should also be used with caution in individuals with liver and kidney problems, gastrointestinal disorders, or pre-existing bleeding disorders like hemophilia.

Individuals who are poor metabolizers of Plavix

The effectiveness of Plavix is dependent on the body’s metabolism—or processing—of the drug. Plavix is metabolized by a specific enzyme protein in the liver called CYP2C19. Some individuals have little or no levels of working CYP2C19 due to genetic differences and are considered “poor metabolizers.” This means that Plavix is not metabolized to its active form and won’t be effective in preventing blood clots. There are genetic tests available to identify people who are poor metabolizers of Plavix, and these individuals may benefit from using a different antiplatelet drug.

Pregnancy and nursing

Plavix is not expected to be harmful to an unborn baby based on limited evidence. However, there is an increased risk of bleeding if Plavix is used during labor, delivery, or with an epidural. For this reason, it’s recommended to stop Plavix five to seven days before giving birth. It’s not known whether Plavix passes into breast milk. Pregnant or nursing women should speak to a healthcare professional to weigh the risks and benefits of Plavix use.

Children

Plavix is not approved by the Food and Drug Administration (FDA) for use in children, and its safety has not been established in this population. Plavix is sometimes used off-label in children with cardiovascular diseases and given at lower doses based on body weight.

Plavix interactions

Serious drug interactions can happen when Plavix is taken with other prescription drugs or over-the-counter (OTC) medicines. It is important to tell your healthcare provider about the medications and supplements you take prior to starting Plavix. The following medications and foods should be avoided while on Plavix:

Prilosec (omeprazole) and Nexium (esomeprazole): These two drugs reduce the antiplatelet activity of Plavix and make it less effective when taken together.
Opioids: Opioid drugs such as oxycodone slow gastric emptying and reduce the absorption of Plavix.
Nonsteroidal anti-inflammatory drugs (NSAIDs): Using Plavix together with ibuprofen, naproxen, or other NSAIDs greatly increases the risk of bleeding.
Warfarin: Blood thinners like warfarin also cause bleeding side effects, so this risk is multiplied with Plavix.
Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs): These types of antidepressants affect platelet activation and are associated with higher levels of bleeding when taken with Plavix.
Prandin (repaglinide): Plavix increases the level of repaglinide in the body. The dose of repaglinide should be lowered if used with Plavix.
Drugs that increase or decrease CYP2C19 activity: Plavix is activated by the liver enzyme CYP2C19. Any medications that affect CYP2C19 activity will also affect the effectiveness of Plavix.
Grapefruit juice: Grapefruit interacts with liver enzymes and makes Plavix less effective.

How to avoid Plavix side effects

1. Take this medication as directed

Take Plavix exactly as instructed. Your pharmacist should also provide you with a medication guide. The typical dose is 75 mg daily and taken in combination with aspirin. If you miss a dose, take Plavix as soon as you remember. If it’s almost time for the next dose, skip the missed dose and take the next dose at the usual time. Do not take two doses at the same time. If you take too much Plavix, seek emergency care immediately.

2. Do not discontinue this medication without seeking medical advice

Plavix is meant to be used as a long-term treatment, and stopping this medication can increase the risk of heart attack or stroke. Follow your healthcare provider’s instructions about how long to take Plavix.

3. Inform your healthcare provider of an upcoming surgery or dental procedures

Talk with your healthcare provider about stopping Plavix before having surgery or a dental procedure. You may be instructed to stop the medication at least five days before the procedure to avoid excessive bleeding.

4. Avoid taking this medication with certain proton pump inhibitors (PPIs)

Prilosec and Nexium are commonly used PPIs that are available OTC and should be avoided with Plavix. Other PPI drugs like Protonix (pantoprazole) can be used instead.

5. Be careful while using sharp objects

While using this medication, bleeding may take longer than usual to stop. Be careful when using sharp objects like scissors and knives, and avoid activities like rough sports that can lead to injuries, bruises, or cuts.

6. Watch for signs of unusual bleeding

Inform your healthcare provider right away if you are coughing up or vomiting blood, have blood in the urine, red or black stools, or bruises that appear without a known cause.

7. Tell your healthcare provider about all medical conditions

Serious side effects of Plavix can be avoided by telling your healthcare provider about all past and current medical conditions, especially the following:

Peptic ulcers or other gastrointestinal disorders
Bleeding in the brain
Bleeding disorders like hemophilia
Liver problems
Kidney problems
Any history of drug allergies

Also inform your healthcare provider if you are pregnant, planning on becoming pregnant, or are breastfeeding.

8. Tell your healthcare provider about all medications being taken

Drug interactions between Plavix and other medications can lead to serious side effects. Tell your healthcare provider about all prescription drugs and OTC medicines you’re taking, especially the following:

Prilosec (omeprazole) and Nexium (esomeprazole)
Opioids such as oxycodone
NSAIDs
Blood thinners such as warfarin
SSRIs and SNRIs
Prandin (repaglinide)

9. Store Plavix correctly and out of the reach of children

Plavix should be stored at room temperature (77°F) in a sealed container away from light, moisture, and heat. This medication must be kept out of the reach of children.