Metabolic differences of current thienopyridine antiplatelet agents

INTRODUCTION: Antithrombotics are one of the most commonly prescribed classes of medication around the world. The thienopyridines are an integral part of antithrombotic therapy and are prescribed for various indications including acute coronary syndrome, peripheral vascular disease and cerebrovascular disease. These drugs have distinct metabolic pathways, which lead to the formation of active metabolites that produce both observed clinical differences as well as pharmacokinetic and pharmacodynamic differences in response. AREAS COVERED: The authors describe the pharmacokinetic and pharmacodynamic behavior of three of the currently available thienopyridines, namely ticlopidine, clopidogrel and prasugrel. The authors also describe and discuss the drug interaction and pharmacogenomic factors which may impact safety and drug efficacy. EXPERT OPINION: P2Y(12)-ADP receptor antagonism has proven to be effective at preventing thrombosis. Differences in the activation of these drugs, cytochrome metabolism, concomitant drug use and pharmacogenomics have an impact on thienopyridine use. Clopidogrel remains the thienopyridine drug with the most approved indications for use. Prasugrel has proven to be efficacious but is associated with a higher bleeding risk in comparison to clopidogrel and therefore has to be used in appropriate clinical indications.