The CPIC Guideline for CYP2C19 and proton pump inhibitor (PPI) dosing is now published in Clinical Pharmacology and Therapeutics. The accepted article can be accessed on the PharmGKB page for omeprazole, lansoprazole, pantoprazole, dexlansoprazole, and on the CPIC website.
PPIs inhibit the final pathway of acid production, which leads to inhibition of gastric acid secretion. PPIs are widely used in the treatment and prevention of many conditions including gastroesophageal reflux disease, gastric and duodenal ulcers, erosive esophagitis, H. pylori infection, and pathological hypersecretory conditions. The first-generation inhibitors omeprazole, lansoprazole and pantoprazole are extensively metabolized by the cytochrome P450 isoform CYP2C19 and to a lesser extent by CYP3A4. The second-generation PPI dexlansoprazole appears to share a similar metabolic pathway to lansoprazole. CYP2C19 genotypes have been linked to PPI exposure and in turn to PPI efficacy and adverse effects.
The CPIC guideline summarizes evidence from the literature and provides therapeutic recommendations for omeprazole, lansoprazole, pantoprazole, dexlansoprazole based on CYP2C19 genotype. For therapeutic recommendations and further details, please refer to the Clinical Pharmacogenetics Implementation Consortium (CPIC) Guideline for CYP2C19 and Proton Pump Inhibitor Dosing.