title: Intragastric pH during treatment with omeprazole: role of Helicobacter pylori and H. pylori-associated gastritis.
abstract: BACKGROUND
  Omeprazole treatment produces lower intragastric pH values 4 weeks after cure of Helicobacter pylori infection than before. We therefore investigated the effect of healing H. pylori-associated gastritis on intragastric pH in the presence and in the absence of omeprazole therapy.
  
  
  METHODS
  Before and on day 8 of omeprazole, 20 mg once daily, 24-h intragastric pH-recordings were performed in 14 subjects with H. pylori infection and repeated 4 and 52 weeks after cure of infection. Gastritis severity in corpus and antrum was graded by using a modified Sydney system.
  
  
  RESULTS
  In the absence of omeprazole administration, median 24-h pH values before cure did not differ from those 4 and 52 weeks after cure. On day 8 of omeprazole administration, 24-h pH values were much higher before cure (median, 5.15; 95% confidence interval (CI), 4.3-6.0) than 4 weeks (3.6; 2.1-4.4; P < 0.001) and 52 weeks after cure (3.0; 2.1-4.4; P < 0.001). The activity of corpus and antral gastritis was not associated with the magnitude of H+ change induced by omeprazole.
  
  
  CONCLUSIONS
  The increased pH produced by omeprazole during H. pylori infection is likely to be due to neutralizing substances produced by H. pylori and not to H. pylori-induced gastritis.
authors.affiliation: Division of Gastroenterology, CHUV, Lausanne, Switzerland.
authors.forename: E F
authors.initials: EF
authors.lastname: Verdú
authors.forename: D
authors.initials: D
authors.lastname: Armstrong
authors.forename: J P
authors.initials: JP
authors.lastname: Idström
authors.forename: J
authors.initials: J
authors.lastname: Labenz
authors.forename: M
authors.initials: M
authors.lastname: Stolte
authors.forename: G
authors.initials: G
authors.lastname: Börsch
authors.forename: A L
authors.initials: AL
authors.lastname: Blum
mesh_terms: D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005753:Gastric Mucosa / Q000187:drug effects* / Q000473:pathology; D005755:Gastrins / Q000032:analysis; D005756:Gastritis / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects*; D008297:Male; D009853:Omeprazole / Q000008:administration & dosage / Q000627:therapeutic use*; D011863:Radioimmunoassay
chemical_list: D000897:Anti-Ulcer Agents; D005755:Gastrins; D009853:Omeprazole