Effect of low-dose omeprazole on gastric acid secretion in duodenal ulcer patients

Aliment Pharmacol Ther. 1988 Jun;2(3):263-8. doi: 10.1111/j.1365-2036.1988.tb00696.x.


The effect of 7 days of oral dosing with 5 mg day-1 and 20 mg day-1 omeprazole on basal and pentagastrin-stimulated gastric acid output was studied in nine duodenal ulcer patients. Basal acid output measured 5-6 h post-dosing was decreased by a mean of 75% on 5 mg omeprazole and by 90% on 20 mg omeprazole (P less than 0.05 and P less than 0.01, respectively). Peak acid output measured 6-7 h post-dosing was decreased by a mean of 75% on 5 mg omeprazole and 97% on 20 mg omeprazole (P less than 0.01 for each). There was a wide interindividual variation in response to the 5 mg dose, with five of the nine patients having more than 90% inhibition of peak acid output, but two patients having less than 40% inhibition. This unpredictable response to daily low-dose omeprazole therapy makes it unsuitable for maintenance treatment.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Double-Blind Method
  • Duodenal Ulcer / physiopathology*
  • Female
  • Gastric Acid / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Omeprazole / administration & dosage
  • Omeprazole / adverse effects
  • Omeprazole / pharmacology*


  • Omeprazole