Myocardial Infarction & Peripheral Vascular Diseases Q 2

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Aspirin is administered to the client experiencing an MI because of its:

  

     A. Antipyretic action

     B. Antithrombotic action

     C. Antiplatelet action

     D. Analgesic action

    

    

Correct Answer: B. Antithrombotic action

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Aspirin does have antipyretic, antiplatelet, and analgesic actions, but the primary reason ASA is administered to the client experiencing an MI is its antithrombotic action. Aspirin is a cyclooxygenase-1 (COX-1) inhibitor. It is a modifier of the enzymatic activity of cyclooxygenase-2 (COX-2). Unlike other NSAIDs (ibuprofen/naproxen), which bind reversibly to this enzyme, aspirin binding is irreversible. It also blocks thromboxane A2 on platelets in an irreversible fashion preventing platelet aggregation.

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Option A: Researchers hypothesize that due to the blocking of the COX pathway, the arachidonic acids are shuttled into the lipoxygenase pathway. The production of anti-inflammatory lipoxins is a result of the modification of prostaglandin-endoperoxide synthase (PTGS2), also called COX-2, that results in the production of lipoxins, most of which are anti-inflammatory.

Option C: Plasma levels of aspirin can range from 3 to 10 mg/dL for therapeutic doses to as high as 70 to 140 mg/dL for acute toxicity. Due to delayed absorption of certain preparations, levels should be checked 4 hours after consumption and every 2 hours after that until maximum levels are reached.

Option D: Salicylates have been derived from the willow tree bark. The Sumerians were noted to have used remedies derived from the willow tree for pain management as far back as 4000 years ago. Hippocrates used it for managing pain and fever. He even utilized tea brewed from it for pain management during childbirth.

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