MEDICAL DISCLAIMER:The contents are under continuing development and improvements and despite all efforts may contain errors of omission or fact. This is not to be used for the assessment, diagnosis or management of patients. It should not be regarded as medical advice by healthcare workers or laypeople. It is for educational purposes only. Please adhere to your local protocols. Use the BNF for drug information. If you are unwell please seek urgent healthcare advice. If you do not accept this then please do not use the website.


Learning objectives

  • Learning
  • Understand
  • Integrate
  • Reflect

Clopidogrel may show a delayed onset of platelet inhibition of 48 h because it requires activation by two-stage hepatic metabolism.

About : Always Clopidogrel check the BNF link here
  • Thienopyridine platelet antagonist P2Y12 receptor blocker
  • Ask cardiologist before stopping dual antiplatelet early post stenting.
  • Blocks platelet activation
  • Works synergistically with Aspirin
  • Genetic variations in metabolism
Mode of action
  • Prodrug which requires activation in the liver
  • Clopidogrel blocks the activation of the platelet P2Y12 receptor - antiplatelet agent
  • Selective and irreversible inhibition of ADP binding to platelet receptors
  • Prolongs the bleeding time
  • NSTEMI (CURE study) treat for up to 1 year
  • STEMI (CLARITY study and COMMIT study) for 14 days
  • PCI patients (CLASSICS trial and PCI CURE)
  • Bare metal stent - at least one month Treatment
  • Drug eluting stent - 12 months Aspirin + Clopidogrel treatment
  • Aspirin intolerant patients requiring antiplatelet therapy
  • Bleeding 1% increased risk of major bleeds
  • Trauma, imminent surgery, Thrombocytopenia
  • Effects reduced by omeprazole
  • STEMI/ACS: Loading dose 300-600 mg po
  • ACS/Ischaemic Stroke/TIA:Maintenance dose 75 mg od
Side effects
  • Diarrhoea, Rash, Dyspepsia, Bleeding takes 7 days for effect to reduce.