ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Antiplatelet (P2Y12 ADP receptor antagonist) Pregnancy: Use only if clearly indicated. Limited data.

Clopidogrel

Brand names: Plavix

Adult dose

Dose: ACS/PCI: 300–600 mg loading, then 75 mg daily; TIA/Stroke: 300 mg loading then 75 mg daily
Route: Oral
Frequency: Once daily (maintenance)
Max: 600 mg loading; 75 mg/day maintenance
ACS/PCI (DAPT): loading 300 mg (or 600 mg for PCI), then 75 mg OD for 12 months with aspirin. TIA (DAPT): 300 mg day 1 then 75 mg OD + aspirin 75 mg OD for 21 days (POINT trial), then clopidogrel monotherapy. Peripheral arterial disease: 75 mg OD monotherapy.

Paediatric dose

Route: Not applicable
Frequency: Not licensed in children
Max: Not licensed
Not licensed in children. Specialist use for Kawasaki disease antiplatelet therapy under paediatric cardiology guidance.

Dose adjustments

Renal

No dose adjustment required.

Hepatic

Use with caution in hepatic impairment; avoid in severe.

Clinical pearls

  • Prodrug requiring CYP2C19 activation — genetic variants cause resistance (15–20% poor metabolisers in Europeans, higher in Asians)
  • Use pantoprazole (not omeprazole) as the PPI with clopidogrel (less CYP2C19 inhibition)
  • Discontinue 5–7 days before elective surgery (CABG, major procedures)
  • After coronary stent — do not stop DAPT without cardiology advice (stent thrombosis risk)
  • Ticagrelor or prasugrel preferred over clopidogrel in ACS (PLATO/TRITON trials)

Contraindications

  • Active pathological bleeding
  • History of intracranial haemorrhage
  • CYP2C19 poor metaboliser (reduced efficacy — genetic testing may guide therapy)

Side effects

  • Bleeding (GI, intracranial, mucocutaneous)
  • GI upset
  • Thrombotic thrombocytopenic purpura (TTP) — rare
  • Rash and pruritus
  • Neutropenia (rare)

Interactions

  • PPIs (especially omeprazole) — CYP2C19 inhibition reduces clopidogrel activation; use pantoprazole instead
  • Aspirin — dual antiplatelet therapy; increases bleeding risk
  • NSAIDs — increased bleeding risk
  • Warfarin — increased bleeding risk

Monitoring

  • Signs of bleeding
  • Platelet count (TTP suspicion)
  • FBC

Reference: BNFc; BNF; NICE NG185; ESC ACS/NSTE Guidelines; POINT trial. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways