• Type: Antiplatelet, NSAID
  • Dosage Forms: tablet, delayed-release tablet, chewable tablet, enteric-coated tablet, oral chewing gum, extended release capsule
  • Common Trade Names: Aspirin, Baby Aspirin, ASA
  • Usage: Analgesic, antipyretic, antiplatelet

Adult Dosing

  • 325 to 650mg orally or rectally every 4 hours as needed, not to exceed 4 g/day
  • 324mg chewable for ACS
  • 81mg (baby) Aspirin common daily cardiac risk reduction dose

Pediatric Dosing

Avoid use in children, especially those with viral syndrome, due to risk of Reye syndrome

  • Fever, pain
    • >12yo: 325 to 650mg PO or PR q4-6h
  • 2-11yo: 10 to 15 mg/kg PO or PR q4-6h
  • Kawasaki: 80-100 mg/kg/day (divided q4-6h) PO until afebrile 48-72h or day 14, then 3-5mg/kg/day until no evidence of coronary changes
  • Stroke: 1 to 5 mg/kg/day PO
  • Juvenile RA: 90-130 mg/kg/day PO divided q4-6h

Special Populations

  • Pregnancy Rating: C (1st-2nd trimester), D (3rd trimester)
  • Lactation: Infant risk cannot be ruled out
  • Renal Dosing: if CrCl <10, avoid use
  • Hepatic Dosing: avoid if severe impairment


  • Allergy to class/drug
  • Syndrome of asthma, rhinitis, and nasal polyps

Adverse Reactions


  • See Aspirin (Salicylate) Toxicity
  • Reye syndrome - Children and teenagers should not use this medicine for chicken pox or viral symptoms
  • GI ulcer
  • Hemorrhage
  • Exudative age-related macular degeneration
  • Bronchospasm
  • Tinnitus
  • Angioedema



  • Half-life: 20-60m, Salicylic acid: 6h
  • Metabolism: Hepatic
  • Excretion: Renal, dialyzable
  • Mechanism of Action: Irreversible cyclooxygenase inhibitor, thus preventing prostaglandin synthesis and platelet activation

See Also