CYP2C19 and duodenal ulcer: In terms of pharmacokinetics, ilaprazole showed more prolonged plasma half-life time (8.1–10.1 hr) than prior PPIs (0.5–2 hr) [33] and it has been well known that ilaprazole is minimally metabolized by CYP2C19, main metabolic enzyme for first- and second-generation PPIs, so that lower variability of the medicinal effect was found among these PPI takers and there were no differences in mean intragastric pH for 24 hr, the percentage of time of a pH > 4, and healing rate of duodenal ulcer among the different phenotypes of CYP2C19 [34, 35].