Antiplatelet Therapy for Secondary Stroke Prevention

Introduction to Antiplatelet Options

The American College of Chest Physicians recommends clopidogrel (75 mg once daily) or aspirin/extended-release dipyridamole (25 mg/200 mg twice daily) over aspirin alone as first-line antiplatelet therapy for secondary stroke prevention in patients with a history of noncardioembolic TIA 1, 2

Daily long-term antiplatelet therapy should be prescribed immediately for secondary prevention of stroke and other vascular events in patients with noncardioembolic TIA, with options including clopidogrel 75 mg once daily 1 and aspirin/extended-release dipyridamole 25 mg/200 mg twice daily 3, 4
Aspirin (75-100 mg daily) remains an acceptable alternative if the preferred agents are not tolerated 1
Cilostazol (100 mg twice daily) is another alternative but less preferred than clopidogrel or aspirin/dipyridamole 1

For patients with persistent or paroxysmal atrial fibrillation who have had a cardioembolic TIA, long-term oral anticoagulation is recommended (target INR 2.0-3.0) 3, 4, 5
Aspirin (325 mg/day) or clopidogrel (75 mg) should only be used if oral anticoagulation cannot be administered 3, 6
Dabigatran may be considered as an alternative to adjusted-dose vitamin K antagonist therapy, but is contraindicated in patients with severe renal impairment 1, 2

For patients who have had an atherothrombotic TIA while taking aspirin (treatment failure), switching to clopidogrel 75 mg daily or aspirin 25 mg plus sustained-release dipyridamole 200 mg twice daily is recommended 3, 4, 5
For patients with recent TIA and unstable angina or non-Q-wave myocardial infarction, combination of clopidogrel 75 mg and aspirin 75-100 mg is recommended 3, 6
For patients with TIA who are undergoing carotid endarterectomy, aspirin therapy (50-325 mg) should be started before surgery unless contraindicated 3

Clopidogrel is preferred over ticlopidine due to fewer side effects and less monitoring requirements 3, 4
Herbal supplements like feverfew, garlic, ginkgo biloba, ginger, and ginseng may alter bleeding time 3
St. John's Wort can enhance the metabolism of warfarin 3

Delaying initiation of antiplatelet therapy after TIA (should be started immediately) 3, 2
Using oral anticoagulation for noncardioembolic TIA (not recommended unless there's a separate indication) 3, 1