Thienopyridines

Thienopyridines are a class of medications that act as a P2Y12 receptor blocker resulting in the inhibition of platelet aggregation.

They are orally administered and have a long effective half-life of 5-7 days.

Names

Clopidogrel (Plavix), prasugrel (Effient), ticagrelor (Brilinta), and ticlopidine (Ticlid)

Indications

Thienopyridines are indicated in all acute coronary syndrome cases unless surgery is needed. Clopidogrel can also be used as an adjunct to fibrinolytic therapy in patients intolerant to aspirin. Regardless of the type of stent used during PCI, thienopyridines are preferred to be continued for 12 months if possible.

Adverse Reactions

Bleeding, neutropenia (rare), thrombotic thrombocytopenic purpura or TTP (rare)

Miscellaneous

Prasugrel is not recommended in a patient with a prior history of stroke or TIA. Ticlopidine is rarely used due to the risk of thrombocytopenia and TTP (thrombotic thrombocytopenic purpura).

Thienopyridines must be discontinued for 5-7 days prior to CABG unless urgent and the bleeding risk is less than the benefit of revascularization.

Platelet function assays are available to measure a patient’s response to clopidogrel therapy. The common practice is to use prasugrel or ticagrelor if the patient is found to be clopidogrel resistant.