Aspirin
Brand names: Bayer, Ecotrin
Class: 🩸 Anticoagulants & Antiplatelets
On board day, aspirin is the antiplatelet you start (or continue) after an arterial event and rarely for primary prevention anymore. It irreversibly inhibits COX-1 in platelets, blocking thromboxane A2 for the platelet's lifespan (~7–10 days). Indications are secondary prevention after MI or non-cardioembolic stroke, dual antiplatelet therapy after coronary stent placement, and Kawasaki disease in pediatrics. Primary prevention has been narrowed by USPSTF: routinely avoid in adults ≥60, individualize 40–59 with high CV risk and low bleed risk. Avoid in children with viral illness (Reye syndrome). Stop 7–10 days before non-urgent surgery if bleeding risk dominates.
✅ Indications
Secondary ASCVD prevention, post-MI, post-stroke (non-cardioembolic), post-stent (DAPT), Kawasaki disease, (limited primary prevention).
⚙️ Mechanism of Action
Irreversible COX-1 inhibition → ↓ thromboxane A2 → ↓ platelet aggregation.
📏 Dosing
Low-dose: 81 mg daily (most cardiac indications). Anti-inflammatory: 650 mg q4h.
🚫 Contraindications
Active bleeding, children <16 with viral illness (Reye syndrome), hypersensitivity (triad: aspirin + asthma + nasal polyps).
⚠️ Adverse Effects
GI bleed, peptic ulcer, tinnitus (toxicity), Reye syndrome in kids, hypersensitivity.
🔬 Monitoring
Bleeding signs.
💎 Board Pearls
- 👶 Reye SYNDROME — avoid in kids <16 with viral illness (flu, chickenpox).
- 💊 LOW-DOSE (81 mg) = antiplatelet. HIGH-DOSE = analgesic/antiinflammatory. Different indications!
- 🤰 Low-dose aspirin (81 mg) for preeclampsia PREVENTION (starting 12–28 wks in high-risk patients).
- 📉 USPSTF 2022: aspirin for primary prevention NOT recommended ≥60 yrs (bleeding > benefit).
Practice Questions
A parent calls the clinic about a 9-year-old with fever, cough, and body aches who tested positive for influenza A two days ago. Which of the following antipyretic/analgesic options should the nurse practitioner AVOID recommending?
Related Drugs in This Class
- Warfarin — Coumadin, Jantoven
- Apixaban — Eliquis
- Rivaroxaban — Xarelto
- Clopidogrel — Plavix
Sources
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