Pharm 101: Clopidogrel



  • Thienopyridine
  • Reduce platelet aggregation by inhibiting ADP pathway of platelets
  • Irreversibly inhibits ADP P2Y12 receptor on platelets for life of platelet
  • Unlike aspirin, no effect on prostaglandin metabolism
  • Prodrug
  • Hepatic metabolism to active and inactive metabolites
  • 80% of platelet activity inhibited within five hours of loading dose of 300mg
  • Effects lasts for life of platelet, duration of anti-platelet effect 7-10 days
  • Elimination half-life 30-60 minutes
  • Following oral dose, 50% excreted in urine and 46% in faeces in next five days
Clinical uses
  • Ischaemic heart disease including NSTEMI, STEMI, pre/post stent
  • Peripheral vascular disease
  • Stroke prevention
  • Dosage 75mg daily, or 300-600mg loading dose
Adverse effects
  • Gastrointestinal upset
  • Bleeding
  • Thrombotic thrombocytopenic purpura
Further Reading

Pharmacology 101

Top 200 drugs

MBBS (UWA) CCPU (RCE, Biliary, DVT, E-FAST, AAA) Adult/Paediatric Emergency Medicine Advanced Trainee in Melbourne, Australia. Special interests in diagnostic and procedural ultrasound, medical education, and ECG interpretation. Editor-in-chief of the LITFL ECG Library. Twitter: @rob_buttner

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