Therapeutic impact of CYP2C19 pharmacogenetics on proton pump inhibitor-based eradication therapy for Helicobacter pylori.

Current regimens for the eradication of Helicobacter pylori consist of a proton pump inhibitor (PPI) plus one or two antibacterial agents, such as amoxicillin (AMPC), clarithromycin (CAM) or metronidazole (MNZ). PPIs are mainly metabolized by S-mephenytoin 4'-hydroxylase (CYP2C19) in the liver. The polymorphism of CYP2C19 is associated with the pharmacokinetics and pharmacodynamics of PPIs. Eradication rates by PPI-based therapies are also affected by this genotype, as well as bacterial resistance to antibiotics. An individualized treatment strategy based on CYP2C19-related pharmacogenetics or pharmacogenomics and bacterial resistance is expected to increase the cure rate of the initial treatment. It is also necessary to recognize that there is a possible drug-drug interaction between some of the drugs used in this treatment regimen.