title: Stability of gastric secretory inhibition during 6-month treatment with omeprazole in patients with gastroesophageal reflux disease.
abstract: OBJECTIVE
  A trend toward relapse of reflux symptoms and esophagitis during long-term treatment with proton pump inhibitors has been reported. The purpose of this study was to evaluate the existence of tachyphylaxia to the effect of proton pump inhibitors on gastric acidity and gastroesophageal reflux over time.
  
  
  METHODS
  A total of 23 patients with reflux esophagitis underwent 24-h intragastric and intraesophageal pH-metry after 7, 90, and 180 days of continued dosing with 20 mg of omeprazole once daily before breakfast.
  
  
  RESULTS
  The total median percentages of time gastric pH <4 (interquartile range) were 49% (35-70%), 60% (36-76%), and 42% (26-66%) after 7, 90, and 180 days (p = 0.14). Percentages of time gastric pH <3 were 41%, 54%, and 34%, respectively (p = 0.19). The median percentages of total time esophageal pH <4 were 1.1%, 2.5%, and 1.1%, respectively (p = 0.70). Healing of esophagitis was achieved in 84% of the patients after 6 months. Heartburn improved in six, worsened in three, and was unchanged in 10 patients (p = 0.16). There was no statistical significant relationship between change in esophageal acid exposure and change in severity of heartburn.
  
  
  CONCLUSIONS
  A dose of 20 mg of omeprazole once daily consistently controlled patients' symptoms and kept gastric acidity at a stable level over a period of 6 months. There is no evidence of diminution in the effects of 20 mg of omeprazole over time that could indicate the development of tolerance.
authors.affiliation: Division of Gastroenterology, Institute of Medicine, Haukeland Hospital, University of Bergen, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Tefera
authors.forename: J G
authors.initials: JG
authors.lastname: Hatlebakk
authors.forename: A
authors.initials: A
authors.lastname: Berstad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005745:Gastric Acidity Determination; D005764:Gastroesophageal Reflux / Q000188:drug therapy* / Q000378:metabolism* / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D009853:Omeprazole / Q000627:therapeutic use*; D054328:Proton Pump Inhibitors; D013618:Tachyphylaxis; D013997:Time Factors
chemical_list: D054328:Proton Pump Inhibitors; D009853:Omeprazole