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
Pharm 101 700

Pharmacology 101

Top 200 drugs

MBBS CCPU (RCE, Biliary, DVT, E-FAST, AAA) Rob is an Emergency Medicine Advanced Trainee based in Melbourne, Australia. He has special interests in medical education, ECG interpretation, and the use of diagnostic and procedural ultrasound in the undifferentiated and unwell patient.

Follow him on twitter: @rob_buttner | ECG Library |

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