What are the indications for anticoagulants and antiplatelets (anti-platelet agents) in patients with a history of stroke?

From the Guidelines

For ischemic stroke patients, immediate therapy typically includes aspirin 325mg initially, followed by 81mg daily long-term, as recommended by the most recent guidelines 1.

Anticoagulants and Antiplatelet Therapy

Anticoagulants and antiplatelet medications are essential for stroke prevention and treatment. The choice of therapy depends on the etiology of the stroke, with antiplatelet agents recommended for non-cardioembolic ischemic stroke or TIA 1.

• Aspirin 81-325 mg daily, clopidogrel 75 mg daily, or aspirin + dipyridamole 25/200 mg daily are acceptable options for initial therapy 1.
• For high-risk patients with recent minor stroke or TIA, dual antiplatelet therapy with aspirin 81mg plus clopidogrel 75mg daily for 21 days followed by single antiplatelet therapy long-term reduces recurrent stroke risk 1.
• In patients with an acute ischemic stroke or TIA who were not on an antiplatelet agent, a single loading dose of 160 mg should be administered after an intracranial hemorrhage is ruled out on neuroimaging studies 1.

Specific Considerations

• For patients with extracranial carotid or vertebral artery dissection, either antiplatelet therapy or oral anticoagulants are recommended for at least 3 months 1.
• In patients with ischemic stroke or TIA and a carotid web in the ipsilateral vascular territory, antiplatelet therapy is recommended 1.
• For patients with ischemic stroke or TIA and positive anti-phospholipid who do not fulfill criteria for anti-phospholipid syndrome, antiplatelet therapy is recommended 1.

Treatment Individualization

Treatment should be individualized based on stroke etiology, bleeding risk, comorbidities, and medication interactions, with regular monitoring for bleeding complications 1.

• The selection of an antiplatelet agent should be individualized on the basis of patient risk factor profiles, cost, tolerance, and other clinical characteristics 1.
• The addition of aspirin to clopidogrel increases the risk of hemorrhage and is not recommended for routine secondary prevention after ischemic stroke or TIA 1.

From the FDA Drug Label

1.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease 2.2 Recent MI, Recent Stroke, or Established Peripheral Arterial Disease 14.2 Recent Myocardial Infarction, Recent Stroke, or Established Peripheral Arterial Disease

Clopidogrel is indicated for patients with recent stroke. The dosage and administration for these patients are described in section 2.2 of the label.

• Key points:
  • Clopidogrel is used for recent stroke patients
  • The label provides information on dosage and administration for these patients The label does not provide direct information on the use of anticoagulants for stroke patients, only antiplatelet agents like clopidogrel 2.

From the Research

Anticoagulants and Antiplatelets for Stroke Patients

• Anticoagulants and antiplatelets are crucial in the prevention of ischemic stroke, with antiplatelets being used for noncardioembolic stroke prevention and anticoagulants for cardioembolic stroke prevention 3.
• Commonly used antiplatelets include aspirin, clopidogrel, and aggrenox, while commonly used anticoagulants include warfarin, dabigatran, rivaroxaban, apixaban, and edoxaban 3.
• The use of anticoagulants in acute ischemic stroke is controversial, with some studies suggesting no significant effect in improving clinical outcomes 4.
• Antiplatelet therapy is central in the management of patients with ischemic nonembolic stroke and transient ischemic attacks, with aspirin, clopidogrel, and aspirin plus dipyridamole being the mainstays of treatment 5.
• Dual antiplatelet treatment may be beneficial in the early treatment of atherosclerotic large vessel disease, but long-term use should be individualized due to the higher risk of bleeding complications 5.

Treatment Guidelines

• Aspirin is recommended as the primary medication for secondary stroke prevention, with a dose of 160 mg to 300 mg daily within 48 hours of stroke onset reducing the risk of death or dependency 6.
• Other antiplatelet drugs, such as clopidogrel, cilostazol, prasugrel, and intravenous ozagrel sodium, are also available for use in acute ischemic stroke 6.
• Direct oral anticoagulants are the primary choice for ischemic stroke with nonvalvular atrial fibrillation, while warfarin is the anticoagulant of choice for secondary stroke prevention in patients with mechanical valve replacements 6.
• Antithrombotic therapy should be individualized for patients with cardiovascular disease, taking into account the underlying condition and the risk of stroke 7.

Mechanisms and Risks

• Antiplatelets and anticoagulants exhibit their effect by blocking the activation pathways of platelets and the coagulation cascade, respectively 3.
• Each of these drugs has a unique mechanism of action, and they share some common adverse events such as gastrointestinal bleeding and intracranial hemorrhage in more serious cases 3.
• The use of anticoagulants and antiplatelets requires careful assessment of the benefits and risks, particularly in patients with a high risk of bleeding complications 3, 5, 6.