title: Effects of different omeprazole dosing on gastric pH in non-variceal upper gastrointestinal bleeding: A randomized prospective study.
abstract: OBJECTIVE
  We aimed to identify the best method of omeprazole (OME) application with respect to intragastric pH, cytochrome P450 2C19 (CYP2C19) genotype and phenotype.
  
  
  METHODS
  The patients with non-variceal upper gastrointestinal bleeding (NVUGIB) were prospectively enrolled. After the achievement of endoscopic hemostasis, the patients were randomized to 40-mg intravenous (i.v.) OME bolus injection every 12 h or 8-mg/h continuous i.v. infusion for 72 h after an 80-mg i.v. OME bolus administration. The intragastric pH was recorded for 72 h. The CYP2C19 variant alleles (*2, *3, *17) were analyzed and the serum concentrations of OME and 5-hydroxyomeprazole (5-OH OME) were determined.
  
  
  RESULTS
  Altogether 41 Caucasians (18 in the OME infusion [OI] group and 23 in the OME bolus [OB] group) were analyzed. The median percentage of time with an intragastric pH > 4.0 was higher in the infusion group than in the OB group over 48 h (100% vs 96.6%, P = 0.009) and 72 h (100% vs 87.6%, P = 0.006), and that at an intragastric pH >6.0 was higher in the OI group than the OB group over 72 h (97.9% vs 63.5%, P = 0.04). Helicobacter pylori infection was correlated with the fastest increase in intragastric pH, especially in the OI group. In both groups, CYP2C19 genotypes (*1/*1, *1/*17, *17/*17) had no essential effect on intragastric pH.
  
  
  CONCLUSIONS
  In patients with NVUGIB, OME i.v. bolus followed by continuous infusion is more effective than OME i.v. bolus every 12 h in maintaining higher intragastric pH, regardless of CYP2C19 genetic polymorphisms. H. pylori infection accelerates the initial elevation of intragastric pH.
authors: Department of Gastroenterology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors: Adam
authors: http://orcid.org/0000-0001-7171-7912
authors: A
authors: Chwiesko
authors: Department of Clinical Molecular Biology, Medical University of Bialystok, Bialystok, Poland.
authors: Radoslaw
authors: R
authors: Charkiewicz
authors: Department of Clinical Molecular Biology, Medical University of Bialystok, Bialystok, Poland.
authors: Jacek
authors: J
authors: Niklinski
authors: Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland.
authors: Wojciech
authors: W
authors: Luczaj
authors: Department of Inorganic and Analytical Chemistry, Medical University of Bialystok, Bialystok, Poland.
authors: Elzbieta
authors: E
authors: Skrzydlewska
authors: Department of Statistics and Medical Informatics, Medical University of Bialystok, Bialystok, Poland.
authors: Robert
authors: http://orcid.org/0000-0001-6241-8283
authors: R
authors: Milewski
authors: Department of Gastroenterology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors: Andrzej
authors: A
authors: Baniukiewicz
authors: Department of Gastroenterology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors: Eugeniusz
authors: E
authors: Wroblewski
authors: Department of Gastroenterology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors: Mariusz
authors: M
authors: Rosolowski
authors: Department of Gastroenterology and Internal Medicine, Medical University of Bialystok, Bialystok, Poland.
authors: Andrzej
authors: A
authors: Dabrowski
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D065731:Cytochrome P-450 CYP2C19 / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004381:Duodenal Ulcer / Q000097:blood / Q000188:drug therapy / Q000235:genetics; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D005745:Gastric Acidity Determination; D005838:Genotype; D016481:Helicobacter Infections / Q000235:genetics / Q000378:metabolism; D016480:Helicobacter pylori; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D007262:Infusions, Intravenous; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000008:administration & dosage* / Q000097:blood; D010438:Peptic Ulcer Hemorrhage / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D011446:Prospective Studies; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000097:blood; D013276:Stomach Ulcer / Q000097:blood / Q000188:drug therapy / Q000235:genetics; D055815:Young Adult
chemical_list: D054328:Proton Pump Inhibitors; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole
keywords: CYP2C19; Helicobacter pylori; intragastric pH; non-variceal upper gastrointestinal bleeding; proton pump inhibitor