Pharmacist-led CYP2C19 genotyping in patients on clopidogrel therapy following percutaneous coronary intervention

Abstract

A poster presentation regarding pharmacist-led CYP2C19 genotyping in patients on clopidogrel therapy following percutaneous coronary intervention. Background: CYP2C19, a cytochrome P450 enzyme encoded by a highly polymorphic gene, is involved in the metabolism of clinically important drugs such as clopidogrel. The 2013 Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines for CYP2C19 genotype and clopidogrel therapy, classify CYP2C19 genotypes into 4 groups according to metaboliser status in relation to clopidogrel: ‘Extensive metabolisers’, carrying only normal function alleles (EMs *1/*1), ‘ultra-rapid metabolisers’, carrying at least one gain-of-function (GoF) allele (UMs *1/*17, *17/*17), ‘intermediate metabolisers’, carrying one loss-of-function (LoF) allele (IMs *1/*2, *2/*17), and ‘poor metabolisers’, carrying two LoF alleles (PMs *2/*2). Objective: To implement a laboratory-based, pharmacist-led process to genotype patients who were prescribed clopidogrel therapy post-percutaneous coronary intervention (PCI) for the CYP2C19 LoF (*2) and GoF (*17) variant alleles.