The survival and replication cycle of Helicobacter pylori(H.pylori)is strictly dependant on intragastric pH,since H.pylori enters replicative phase at an almost neutral pH(6-7),while at acid pH(3-6)it turns into its coccoid form,which is resistant to antibiotics.On these bases,it is crucial to increase intragastric pH by proton pump inhibitors(PPIs)when an antibiotic-based eradicating therapy needs to be administered.Therefore,several tricks need to be used to optimize eradication rate of different regimens.The administration of the highest dose as possible of PPI,by doubling or increasing the number of pills/day,has shown to be able to improve therapeutic outcome and has often proposed in rescue therapies,even if specific trials have not been performed.A pre-treatment with PPI before starting antibiotics does not seem to be effective,therefore it is discouraged.However,the choice of PPI molecule could have a certain weight,since second-generation substances(esomeprazole,rabeprazole)are likely more effective than those of first generation(omeprazole,lansoprazole).A possible explanation is due to their metabolism,which has been proven to be less dependent on cytochrome P450(CYP)2C19 genetic variables.Finally,vonoprazan,a competitive inhibitor of H+/K+-ATPase present on luminal membrane of gastric parietal cells has shown the highest efficacy,due to both its highest acid inhibition power and rapid pharmacologic effect.However current data come only from Eastern Asia,therefore its strong power needs to be confirmed outside this geographic area in Western countries as well as related to the local different antibiotic resistance rates.
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