Aspirin
Acute coronary syndrome (ACS), Ischemic stroke (antiplatelet), Pericarditis, Fever/analgesia (non-ED use)
Indications
- Acute coronary syndrome (ACS)
- Ischemic stroke (antiplatelet)
- Pericarditis
- Fever/analgesia (non-ED use)
Adult dosing
- acs: dose: 324; unit: mg; route: PO; fixed: true; note: Chewed, not swallowed whole — chewing achieves faster absorption; pericarditis: dose: 650; unit: mg; route: PO; fixed: true; note: q6-8h, taper over weeks; antiplatelet maintenance: dose: 81; unit: mg; route: PO; fixed: true; note: Daily maintenance dose
Pediatric dosing
- kawasaki: dose: 80; maxDose: 100; unit: mg/kg/day; route: PO; weightBased: true; pedNote: High dose during febrile phase — use only under specialist guidance. CAUTION: Risk of Reye syndrome with viral illness — only for Kawasaki or cardiac indications; antiplatelet: dose: 81; unit: mg; route: PO; fixed: true; pedNote: Children >12 years only; 81mg daily fixed dose
Contraindications
- Active GI bleeding or peptic ulcer disease
- Aspirin hypersensitivity or NSAID allergy
- Hemophilia or severe bleeding disorder
- Children with viral illness — risk of Reye syndrome
- Third trimester pregnancy
Clinical pearls
- ACS: 324mg chewed immediately — chewing is critical for rapid buccal absorption and faster platelet inhibition than swallowing
- Do not withhold for GI history in STEMI — benefit outweighs risk in true ACS
- Aspirin allergy in ACS: consider desensitization or clopidogrel 600mg loading dose as alternative
- Aspirin + P2Y12 inhibitor (dual antiplatelet) is standard post-ACS — aspirin is the foundation
- Reye syndrome: never give aspirin to children with viral illness (influenza, varicella)
Source and review
- ACC/AHA STEMI Guidelines 2013 (updated 2015), AHA Stroke Guidelines 2019. Last reviewed: 2024-11-01