title: A case-control study on adverse effects: H2 blocker or proton pump inhibitor use and risk of vitamin B12 deficiency in older adults.
abstract: OBJECTIVE
  Acid-suppressant drugs are commonly prescribed for elderly patients, a population in which vitamin B(12) deficiency is a common disorder. The purpose of this study was to examine the possible association between use of prescription histamine H-2 receptor antagonists (H2RA) or proton pump inhibitors (PPI) and vitamin B(12) deficiency in older adults.
  
  
  METHODS
  This was a case-control study in a University-based geriatric primary care setting. Among patients aged 65 years or older with documented serum vitamin B(12) studies between 1990 and 1997, 53 vitamin B(12)-deficient cases were compared with 212 controls for past or current use of prescription H2RA/PPI according to information in subjects' medical records.
  
  
  RESULTS
  Controlling for age, gender, multivitamin use, and Helicobacter pylori infection, chronic (#10878;12 months) current use of H2RA/PPI was associated with a significantly increased risk of vitamin B(12) deficiency (OR 4.45; 95% CI 1.47-13.34). No association was found between past or short-term current use of H2RA/PPI and vitamin B(12) deficiency.
  
  
  CONCLUSIONS
  These findings support an association between chronic use of H2RA/PPI by older adults and development of vitamin B(12) deficiency. Additional studies are needed to confirm these findings.
authors.affiliation: School of Pharmacy, University of Colorado Health Sciences Center, 4200 E. 9th Ave., C-238, Denver, CO 80262, USA. robert.valuck@uchsc.edu
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Valuck
authors.forename: J Mark
authors.initials: JM
authors.lastname: Ruscin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000009:adverse effects*; D016022:Case-Control Studies; D004334:Drug Administration Schedule; D005260:Female; D006635:Histamine H2 Antagonists / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D008297:Male; D016017:Odds Ratio; D054328:Proton Pump Inhibitors; D014806:Vitamin B 12 Deficiency / Q000139:chemically induced*
chemical_list: D000897:Anti-Ulcer Agents; D006635:Histamine H2 Antagonists; D054328:Proton Pump Inhibitors