Aspirin
| Uses: | acute MI, ischaemic stroke... |
|---|---|
| Mechanism of action | irreversible inhibition of COX1 and COX2 → ↓ platelet synthesis of thromboxane A2 → ↓ platelet aggregation |
| Dose | 300mg loading 75mg maintenance |
| Pharmacokinetics | Absorption PO, PR Distribution Metabolism t½ 15 mins, metabolite = salicylate Elimination renal excretion |
| Time course of action | Duration of effect 7-10 days (ie lifespan of platelets) |
| Adverse effects | GI bleeds - due to ↓ prostaglandin in gastric mucosa Children age <16 |
| Contraindications | Analgesic dose: severe heart failure |