title: Aspirin dosing for the prevention and treatment of ischemic stroke: an indication-specific review of the literature.
abstract: OBJECTIVE
  To evaluate the efficacy of aspirin for the treatment and prevention of ischemic stroke and identify the minimum dose proven to be effective for each indication.
  
  
  METHODS
  PubMed and MEDLINE searches (up to January 2010) were performed to identify primary literature, using search terms including aspirin, stroke prevention, acute ischemic stroke, acetylsalicylic acid, atrial fibrillation, myocardial infarction, and carotid endarterectomy. Additionally, reference citations from publications identified were reviewed.
  
  
  METHODS
  Articles published in English were evaluated and relevant primary literature evaluating the efficacy of aspirin in the prevention of stroke was included in this review.
  
  
  RESULTS
  Antiplatelet therapy is the benchmark for the prevention of ischemic stroke. Aspirin has been proven to prevent ischemic stroke in a variety of settings. Despite the frequency at which aspirin continues to be prescribed in patients at risk of ischemic stroke, there remains confusion in clinical practice as to what minimum dose is required in various at-risk patients. A thorough review of the primary literature suggests that low-dose (50-81 mg daily) aspirin is insufficient for some indications. Acute ischemic stroke treatment requires 160-325 mg, while atrial fibrillation and carotid arterial disease require daily doses of 325 and 81-325 mg, respectively.
  
  
  CONCLUSIONS
  Available evidence suggests that aspirin dosing must be individualized according to indication. Recommendations provided by national guidelines at times recommend lower doses of aspirin than have been proven effective. Higher doses are indicated for stroke prevention in atrial fibrillation (325 mg) and acute ischemic stroke patients (160-325 mg). Aspirin has not yet been proven effective for primary prevention of strokes in men, and a minimum dose for these patients cannot be determined from the available data.
authors.affiliation: Department of Pharmacy, Methodist Hospital (Clarian Health), Indianapolis, IN 46202, USA. aansara@clarian.org
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Ansara
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Nisly
authors.forename: Sally A
authors.initials: SA
authors.lastname: Arif
authors.forename: Julia M
authors.initials: JM
authors.lastname: Koehler
authors.forename: Sarah T
authors.initials: ST
authors.lastname: Nordmeyer
mesh_terms: D001241:Aspirin / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D050197:Atherosclerosis / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology; D002340:Carotid Artery Diseases / Q000097:blood / Q000188:drug therapy / Q000201:enzymology / Q000601:surgery; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D007511:Ischemia / Q000097:blood / Q000188:drug therapy* / Q000201:enzymology; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy / Q000201:enzymology; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D020521:Stroke / Q000201:enzymology / Q000209:etiology / Q000517:prevention & control*; D013928:Thromboxane A2 / Q000378:metabolism
chemical_list: D010975:Platelet Aggregation Inhibitors; D013928:Thromboxane A2; D011451:Prostaglandin-Endoperoxide Synthases; D001241:Aspirin