Proposed Clinical Algorithms for Tailoring Clopidogrel Therapy. Proposed clinical algorithms for tailoring clopidogrel therapy based on CYP2C19 genotype (a,b) or on-treatment platelet reactivity (b). The algorithms do not account for non-genetic or other precision medicine regulators of clopidogrel resistance. 1 Only the most common CYP2C19 genotypes are illustrated; 2 Prasugrel and ticagrelor should be considered when not contraindicated clinically. ACS: acute coronary syndrome; EM: extensive metabolizer; IM: intermediate metabolizer; PCI: percutaneous coronary intervention; PM: poor metabolizer; UM: ultra-rapid metabolizer. Picture from Brown, 2018 \cite{Brown_2018}