Aspirin

Summary

Aspirin is a nonsteroidal anti-inflammatory drug or NSAID drug. It has anti-inflammatory and antipyretic properties that make it great for treating fevers, headaches, and arthritis pain. It is also the treatment of choice for kawasaki disease, a rare inflammatory disease that occurs in children. Importantly, aspirin is a blood thinner, used to prevent thrombotic events like strokes or heart attacks. Aspirin can also be used to treat chest pain in people experiencing acute coronary syndrome. The side effects of aspirin can be divided into findings of acute toxicity and long-term effects. Acute toxicity or overdose is characterized by tinnitus, or a ringing in the ears, which should be reported to the provider immediately. Long term side effects of aspirin use include the development of GI ulcers and bleeding. Aspirin should be avoided in all children, due to the risk of causing Reye syndrome. Finally, aspirin should not be taken with alcohol.

Key Points

• Mechanism
  • Nonsteroidal anti-inflammatory drug (NSAID)
    • Inhibits the COX-2 enzyme which is necessary in the process of many inflammatory arachidonic acid derivatives, including prostaglandins, thromboxanes, and leukotrienes.
    • Reduction of levels of prostaglandins reduces inflammation and fever
  • Antiplatelet
    • Inhibits the COX-1 enzyme, leading to reduced blood clotting
  • Clinical Use
    • Anti-Inflammatory / Antipyretic
      • Arthritic disorders
      • Kawasaki disease
    • Prevent blood clot formation
      • Due to antiplatelet effect of COX inhibition on decreasing thromboxanes, which are normally used in activation of platelets
      • A low dose of aspirin (“baby aspirin”) may be prescribed to prevent blood clots and reduce risk of stroke and myocardial infarction.
      • May also be used to prevent reocclusion of coronary arteries after stent placement
    • Chest pain (angina) management
      • Used in many cases of acute coronary syndrome: angina (stable and unstable), MI, etc.
      • Part of the “MONA” treatment - morphine, oxygen, nitroglycerin, aspirin
  • Side Effects and Adverse Reactions
    • Tinnitus (Ringing in ears)
      • Sign of acute aspirin toxicity (salicylism), usually seen in high doses of aspirin, and should be reported to provider
      • Aspirin overdose is treated with activated charcoal and sodium bicarbonate
    • Stomach ulcers (and GI bleeding)
      • COX-1 enzymes protect the gastrointestinal lining, so by inhibiting COX the stomach lining has less protection and is more prone to ulcers
      • Attributed to long-term aspirin use
      • Other GI symptoms may include anorexia, dyspepsia, nausea, vomiting, diarrhea, constipation, abdominal pain, heartburn, flatulence
      • Should be taken with food and/or water
    • Bleeding
      • Discontinue 7 days before surgery and advise dentist of aspirin use before receiving invasive dental work
      • Observe for signs of bleeding like tarry stools, blood in urine, bleeding gums, ecchymosis, etc.
      • Aspirin should not be taken with other blood thinning medications (e.g. warfarin)
    • Reye’s Syndrome
      • Acute liver failure and encephalopathy (confusion) seen in children who take aspirin (usually for an viral illness)
      • Symptoms include vomiting, lethargy, delirium, coma
      • Aspirin is contraindicated in all children except in rare exceptions (e.g. Kawasaki disease)
      • Instruct parents not to give aspirin to children with flu-like symptoms (use acetaminophen instead)
    • Avoid alcohol
      • The combination of aspirin and alcohol increases the risk of stomach ulcers and GI bleeding, as well as liver damage
    • Premature closing of the ductus arteriosus
      • Should not be taken in 3rd trimester of pregnancy because it can cause premature closing of the ductus arteriosus in the fetus