title: Screening for drug related dyspepsia: an analysis of prescription symmetry.
abstract: OBJECTIVE
  Most patients with severe upper dyspepsia are treated empirically with ulcer drugs. Drug-induced dyspepsia might therefore be reflected in the sequencing of ulcer drugs relative to other medications. Our aim was to screen a large population-base prescription database for evidence of drug-induced dyspepsia.
  
  
  METHODS
  Prescription data on 31,232 incident users of ulcer drugs were drawn from a research database, covering the county of Funen, Denmark. We identified all individuals who had started their first recorded therapies with an ulcer drug and another non-ulcer drug within a 100 day span. In this selected group, there would normally be an equal number starting either drug first, while a dyspepsia-provoking effect of the non-ulcer drug would manifest as an excess of individuals with the ulcer drug prescribed last. This screening method is robust to confounders that are stable over time.
  
  
  RESULTS
  Only non-steroidal antiinflammatory drugs (adjusted rate ratio (RR) 1.8, 95% confidence interval (CI), 1.6-2.0), calcium blockers (RR 1.4, CI 1.2-1.7), corticosteroids (RR 1.1, CI 1.0-1.3), angiotensin converting enzyme inhibitors (RR 1.4, CI 1.1-1.7) and methylxanthines (RR 1.5, CI 1.1-2.2) showed a significant asymmetry suggesting a dyspepsia-provoking effect. An analysis of effect modifiers suggested that the signals for corticosteroids and for angiotensin converting enzyme inhibitors were explained by concurrent use of non-steroidal anti-inflammatory drugs and by underlying congestive heart failure. The signal for non-steroidal anti-inflammatory drugs may be explained by the known reputation of non-steroidal antiinflammatory drugs for causing ulcers.
  
  
  CONCLUSIONS
  There are hardly any important unknown drug effects that mimic acid related dyspepsia. Drug-induced dyspepsia contributes little to the overall use of ulcer drugs.
authors.affiliation: Department of Medical Gastroenterology S, Odense University Hospital, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Hallas
authors.forename: P
authors.initials: P
authors.lastname: Bytzer
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D004415:Dyspepsia / Q000139:chemically induced* / Q000188:drug therapy* / Q000453:epidemiology; D015987:Effect Modifier, Epidemiologic; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D012307:Risk Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D005938:Glucocorticoids