Why is Plavix (clopidogrel) given to patients after a stroke?

From the Guidelines

Plavix (clopidogrel) is given to patients after a stroke to prevent future strokes by reducing the risk of blood clot formation, as recommended by the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack from the American Heart Association/American Stroke Association 1. After experiencing an ischemic stroke (caused by a blood clot blocking blood flow to the brain), patients are at higher risk of having another stroke, particularly in the days and weeks following the initial event.

• The typical dose of clopidogrel is 75 mg taken once daily, usually continued for at least 3 months and often longer depending on the patient's risk factors.
• Some patients may receive a loading dose of 300 mg initially to achieve faster antiplatelet effects.
• Clopidogrel is particularly beneficial for patients who cannot take aspirin due to allergies or side effects, or in combination with aspirin (dual antiplatelet therapy) in certain high-risk situations, although the combination of clopidogrel and aspirin is not recommended for all patients with ischemic stroke or transient ischemic attack 1. The medication works by irreversibly blocking the P2Y12 receptor on platelets, preventing them from being activated by adenosine diphosphate (ADP), which is a key step in the clotting process.
• Patients should be aware that clopidogrel increases bleeding risk, so they should inform healthcare providers before any surgical procedures and watch for signs of unusual bleeding. It's also important to note that the optimal combination of medications, timing of initiation, and duration of dual antiplatelet therapy (DAPT) are still areas of ongoing research, and the risk of DAPT among patients with stroke who may be more likely to experience hemorrhagic transformation of the ischemic stroke or other bleeding complication remains uncertain 1.

From the FDA Drug Label

1. 2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease

In patients with established peripheral arterial disease or with a history of recent myocardial infarction (MI) or recent stroke clopidogrel tablets are indicated to reduce the rate of MI and stroke.

Plavix (clopidogrel) is given to patients after a stroke to reduce the rate of myocardial infarction (MI) and stroke.

• The medication works by inhibiting platelet aggregation, which helps to prevent blood clots from forming.
• It is typically administered at a dose of 75 mg once daily orally without a loading dose.
• The use of clopidogrel in patients with a history of recent stroke is supported by its mechanism of action and clinical studies, as mentioned in the drug label 2.

From the Research

Why Plavix is Given to Patients After a Stroke

Plavix, also known as clopidogrel, is an antiplatelet medication that is commonly given to patients after a stroke to prevent further strokes and other cardiovascular events. The reasons for this are:

• Prevention of Emboli and Thrombus Formation: Antiplatelet medications like Plavix prevent emboli and thrombus formation, which can lead to further vascular occlusion and ischemia 3.
• Reduced Risk of Secondary Stroke: Plavix, in combination with aspirin, has been shown to reduce the risk of secondary stroke, myocardial infarction, and death 3, 4, 5.
• Inhibition of Platelet Activity: Plavix inhibits platelet activity, which can help to prevent the formation of blood clots that can cause strokes 4.
• Comparison with Aspirin: Studies have compared the efficacy of Plavix with aspirin in preventing stroke, and have found that Plavix plus aspirin is more effective than aspirin alone in reducing the risk of recurrent stroke 5.

Key Findings from Studies

Some key findings from studies on the use of Plavix in patients after a stroke include:

• A study published in 2005 found that Plavix plus aspirin resulted in significant inhibition of platelet activity compared to aspirin alone 4.
• A systematic review and meta-analysis published in 2021 found that Plavix plus aspirin was more effective than aspirin alone in reducing the risk of recurrent stroke, but increased the risk of major bleeding events 5.
• Another study published in 2020 found that ticagrelor plus aspirin was more effective than aspirin alone in preventing stroke or death within 30 days, but increased the risk of severe bleeding 6.

Mechanism of Action

The mechanism of action of Plavix involves the inhibition of platelet activation and aggregation, which can help to prevent the formation of blood clots that can cause strokes. This is achieved through the blockade of the P2Y12 receptor, which plays a key role in platelet activation 4, 7.