Efficacy of omeprazole in functional dyspepsia: double-blind, randomized, placebo-controlled trials (the Bond and Opera studies)

Aliment Pharmacol Ther. 1998 Nov;12(11):1055-65. doi: 10.1046/j.1365-2036.1998.00410.x.


Background: The efficacy of H2-receptor antagonists in functional dyspepsia is equivocal and the therapeutic place of proton pump inhibitors in functional dyspepsia is unknown.

Aim: To evaluate the efficacy of proton pump inhibitor therapy in functional dyspepsia.

Methods: Patients (n = 1262) with a clinical diagnosis of functional dyspepsia (persistent or recurrent epigastric pain or discomfort for at least 1 month and a normal upper gastrointestinal endoscopy) were randomized to receive omeprazole 20 mg, 10 mg or identical placebo, for 4 weeks. Symptoms were assessed using validated measures. Helicobacter pylori status was determined pre-entry by a 13C-urea breath test.

Results: On an intention-to-treat analysis (n=1248), complete symptom relief was observed in 38% on omeprazole 20 mg, compared with 36% on omeprazole 10 mg and 28% on placebo (P = 0.002 and 0.02, respectively). Among those with ulcer-like and reflux-like dyspepsia, complete symptom relief was achieved in 40% and 54% on omeprazole 20 mg, and 35% and 45% on omeprazole 10 mg, respectively, compared with 27% and 23% on placebo (all P < 0.05, except omeprazole 10 mg in ulcer-like dyspepsia, P = 0.08). There was no significant benefit of omeprazole over placebo in dysmotility-like dyspepsia. Symptom relief was similar in H. pylori-positive and negative cases.

Conclusions: Omeprazole is modestly superior to placebo in functional dyspepsia at standard (20 mg) and low doses (10 mg) but not in patients with dysmotility-like dyspepsia.

Publication types

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

MeSH terms

  • Adenosine Triphosphatases / antagonists & inhibitors*
  • Adult
  • Anti-Ulcer Agents / therapeutic use*
  • Chi-Square Distribution
  • Confidence Intervals
  • Double-Blind Method
  • Dyspepsia / complications
  • Dyspepsia / drug therapy*
  • Dyspepsia / etiology
  • Female
  • Helicobacter Infections / complications
  • Helicobacter Infections / diagnosis
  • Humans
  • Male
  • Omeprazole / therapeutic use*
  • Quality of Life


  • Anti-Ulcer Agents
  • Adenosine Triphosphatases
  • Omeprazole