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Antiplatelet Pregnancy: Low dose: generally considered safe. High dose: avoid in third trimester.

Aspirin

Brand names: Aspirin, Nu-Seals

Adult dose

Dose: 300 mg loading, then 75 mg daily
Route: Oral (or PR if swallowing impaired)
Frequency: 300 mg once at diagnosis; 75 mg once daily thereafter
Max: 300 mg loading
For TIA and ischaemic stroke: 300 mg immediately. Delay 24 hours if thrombolysis given. Continue 75 mg/day long-term. For acute MI: 300 mg chewed.

Paediatric dose

Route: Oral
Frequency: Antiplatelet: 1–5 mg/kg/day (specialist use only)
Max: 75 mg/day
Avoid in children <16 years (Reye's syndrome risk). Specialist use only for Kawasaki disease or post-cardiac surgery.

Dose adjustments

Renal

Use with caution; avoid if eGFR <10 mL/min.

Hepatic

Avoid in severe hepatic impairment.

Clinical pearls

  • Crushed or dispersed tablets can be given via NG tube
  • PR suppository available when oral route not possible
  • Dual antiplatelet therapy (aspirin + clopidogrel) for 21 days post-TIA/minor stroke per NICE

Contraindications

  • Children under 16 years (Reye's syndrome)
  • Active peptic ulcer
  • Haemophilia or bleeding disorders
  • Hypersensitivity to aspirin or NSAIDs
  • Haemorrhagic stroke

Side effects

  • GI upset and bleeding
  • Tinnitus (high doses)
  • Bronchospasm (in aspirin-sensitive asthma)
  • Prolonged bleeding time

Interactions

  • Anticoagulants — greatly increased bleeding risk
  • Other NSAIDs — increased GI toxicity
  • Methotrexate — increased toxicity
  • SSRIs — increased GI bleeding risk

Monitoring

  • Signs of GI bleeding
  • Blood pressure
  • Renal function if long-term use

Reference: BNFc; BNF; NICE NG128; NICE NG185. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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