Table 1. CYP2C19 phenotypes and the therapeutic recommendations for esomeprazole therapy

PhenotypePhenotype detailsExamples of diplotypesTherapeutic recommendations for esomeprazole
Ultrarapid metabolizer
Normal or increased CYP2C19 activity*17/*17
Be extra alert to insufficient response. For the eradication of H. pylori, increase dose by 50–100%. 
For other conditions, consider dose increase by 50–100%.
Extensive metabolizer
Normal CYP2C19 activity*1/*1
Dose recommended by drug label
Intermediate metabolizer
Decreased CYP2C19 activity
*1/*2
*1/*3
*2/*17
*3/*17
Dose recommended by drug label
Poor metabolizer
Markedly reduced or absent CYP2C19 activity
*2/*2
*2/*3
*3/*3
Dose recommended by drug label

Good quality evidence supports the dose recommendations for poor and intermediate metabolizers; data are lacking for ultrarapid metabolizers.

Table is adapted from Swen J.J., Nijenhuis M., de Boer A., Grandia L. et al. Pharmacogenetics: from bench to byte - an update of guidelines. Clinical pharmacology and therapeutics. 2011;89(5):662–73 (3).

From: Esomeprazole Therapy and CYP2C19 Genotype

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