thienopyridines

Last reviewed 01/2018

  • the two related thienopyridine derivatives, ticlopidine and clopidogrel, are specific inhibitors of the P2Y12 ADP receptor
  • both drugs are inactive and metabolised in the liver
  • ticlodipine has uncommon (0.5-3%) but very serious haematological toxicity including neutropaenia, thrombocytopaenia, thrombotic thrombocytopaenia purpura and (very rarely) aplastic anaemia (1); gastrointestinal side effects and rash are common
  • clopidogrel has a significantly better safety profile than ticlodipine
    • clopidogrel has been associated with gastrointestinal upset and bleeding, but at lower rates than those observed with aspirin
    • there have been a number of reports associating clopidogrel with thrombocytopaenic purpura, neutropaenia and aplastic anaemia; however, this risk has to be put into perspective with over 17,000 patients having been treated, at the time of writing, with clopidogrel in randomised controlled trials with no increased incidence of thrombocytopaenia or neutropaenia noted

Reference:

  1. Patrano C et al.Platelet-active drugs: the relationships among dose, effectiveness, and side effects. Chest 2001;119:39S-63S