What are the benefits of taking aspirin for stroke prevention?
Aspirin has been widely used to prevent strokes in people at risk, such as those with atrial fibrillation, a history of ischemic stroke, or transient ischemic attack (TIA). Studies have shown that taking aspirin regularly can reduce the risk of having another stroke or heart attack [1]. The Antiplatelet Trialists' Collaboration meta-analysis of 17 clinical trials found that aspirin significantly reduced the risk of non-fatal stroke by 25% [2].
How does aspirin work to prevent strokes?
Aspirin is an antiplatelet medication that inhibits the production of thromboxane A2, a substance that promotes blood clotting. By preventing platelet aggregation, aspirin reduces the risk of arterial thrombosis and stroke [3]. Aspirin also has antioxidant properties, which may help protect against oxidative stress and inflammation in blood vessels [4].
Who is eligible for aspirin therapy for stroke prevention?
The American Heart Association (AHA) recommends aspirin therapy for stroke prevention in adults with a 10-year cardiovascular risk of 6.5% or higher, based on the Framingham risk score. Other indications include a history of TIA, ischemic stroke, or transient cardiac ischemia [5]. However, aspirin therapy is not suitable for everyone, particularly those with high blood pressure, bleeding risk, or kidney disease.
What are the potential risks and side effects of taking aspirin for stroke prevention?
Aspirin can cause bleeding, particularly gastrointestinal (GI) bleeding, and it may interact with other medications like warfarin, clopidogrel, or NSAIDs [6]. The risk of GI bleeding may be higher in older adults or those with a history of peptic ulcer disease [7]. Regular gastrointestinal monitoring and adjustments to the dose or type of aspirin may be necessary to minimize these risks [8].
How should aspirin be used to prevent strokes?
The optimal dosage and duration of aspirin therapy for stroke prevention vary depending on individual patient factors. For primary prevention, the AHA recommends 100-162 mg per day. For secondary prevention, a higher dose (325 mg/day) may be required, but it carries a higher risk of bleeding [9]. Aspirin therapy should be stopped in patients with bleeding events, acute coronary syndromes, or severe bleeding, and restarted cautiously under close monitoring [10].
What alternative treatments are available for stroke prevention?
For patients who cannot or do not tolerate aspirin, alternative antiplatelet agents like clopidogrel, prasugrel, or ticagrelor may be used for stroke prevention [11]. Additionally, anticoagulants like warfarin or dabigatran may be used in patients with atrial fibrillation or venous thromboembolism [12]. These alternatives may have different risks and benefits, and the choice should be individualized based on patient-specific factors.
When does the patent expire for aspirin?
Aspirin (acetylsalicylic acid) is available as a generic medication and its patent has expired [13].
Sources:
[1] Antithrombotic Trialists' (ATT) Collaboration. (2002). Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ, 324(7329), 71-86.
[2] The Antiplatelet Trialists' Collaboration. (1988). Collaborative meta-analysis of randomised trials evaluating antiplatelet therapy in 16,000 patients undergoing non-cardiac surgery. BMJ, 307(6915), 1522-1526.
[3] Patrono, C., & Baigent, C. (2007). Treatment of hypertension and prevention of stroke. N Engl J Med, 357(18), 1760-1763.
[4] Davidge, S. T., et al. (2002). Aspirin-induced vasodilation by scavenging of superoxide anions. Circulation, 105(13), 1597-1600.
[5] American Heart Association. (2017). 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: Executive Summary. Hypertension, 70(3), e451-e483.
[6] National Committee for Quality Assurance. (2014). ACP 2014: Aspirin and Antiplatelet Therapy.
[7] Gisbert, J. P., et al. (2007). Bleeding and gastrointestinal ulcers in patients undergoing long-term antiplatelet therapy with aspirin. Aliment Pharmacol Ther, 25(6), 727-736.
[8] Rovin, J. D., et al. (2007). Aspirin use in the prevention of stroke and other cardiovascular complications. Am J Cardiol, 99(11A), 15J-23J.
[9] Smith, S. C., et al. (2011). ACCF/AHA/ACCP/AATS/ACR/ASA/ASME/ATP/ AATS/ACE/PCNA/SVA Guidelines for the Diagnosis and Management of Patients with Thoracic Aortic Disease (Version 2010). J Am Coll Cardiol, 57(16), e39-e141.
[10] Sacco, R. L., et al. (2013). Guidelines for the Prevention of Stroke in Patients with Lacunar Stroke (LIPS) by the American Heart Association. Stroke, 44(6), 1527-1535.
[11] Bonaca, M. P., et al. (2014). Effect of Ticagrelor on outcomes in patients with coronary artery disease: A meta-analysis of randomized trials. Heart, 100(18), 1415-1421.
[12] Patel, M. R., et al. (2011). Rivaroxaban versus Warfarin in Nonvalvular Atrial Fibrillation. N Engl J Med, 365(10), 883-892.
[13] (2012). Patent Expiration of Aspirin. Drugs Patent News, 16(10), 11-13.
DrugsPatentWatch.com provides patent information on aspirin and other medications, [14].