title: Use of calcium channel blockers and risk of hospitalized gastrointestinal tract bleeding.
abstract: BACKGROUND
  We conducted a case-control study of the association between calcium channel blocker use and gastrointestinal (GI) tract bleeding in hypertensive members of a health maintenance organization.
  
  
  METHODS
  Case patients (n=174) were treated hypertensive health maintenance organization members hospitalized for GI tract bleeding between January 1992 and December 1994. Case patients were identified using computerized diagnosis codes and were confirmed by medical record review. Control subjects (n=771) were treated hypertensive members selected from ongoing studies at the health maintenance organization. Computerized pharmacy data and medical records were used to assess medication use and other risk factors for GI tract bleeding.
  
  
  RESULTS
  Compared with beta-blocker users, calcium channel blocker users had an age-, sex- and calendar year-adjusted relative risk (RR) of GI tract bleeding of 2.60 (95% confidence interval [CI], 1.71-3.96). The RR associated with calcium channel blocker use was 2.05 (95% CI, 1.33-3.17) after further adjustment for number of recent visits, diastolic blood pressure, chronic congestive heart failure, and duration of hypertension. No significant dose-response relationship was observed. Compared with beta-blocker users, angiotensin-converting enzyme inhibitor users had an RR of 1.22 (95% CI, 0.75-1.97). Calcium channel blocker use tended to be more strongly associated with risk of lower GI tract bleeding (RR, 2.56; 95% CI, 1.08-6.05) than with risk of upper GI tract bleeding (RR, 1.54; 95% CI, 0.91-2.59) or peptic ulcer-related bleeding (RR, 1.17; 95% CI, 0.62-2.21), although these results were compatible with chance.
  
  
  CONCLUSIONS
  Calcium channel blocker use might be associated with an elevated risk of GI tract bleeding. These findings require confirmation in randomized studies.
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, USA. rkaplan@aecom.yu.edu
authors.forename: R C
authors.initials: RC
authors.lastname: Kaplan
authors.forename: S R
authors.initials: SR
authors.lastname: Heckbert
authors.forename: T D
authors.initials: TD
authors.lastname: Koepsell
authors.forename: F R
authors.initials: FR
authors.lastname: Rosendaal
authors.forename: B M
authors.initials: BM
authors.lastname: Psaty
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000009:adverse effects; D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000009:adverse effects; D000959:Antihypertensive Agents / Q000009:adverse effects*; D002121:Calcium Channel Blockers / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D012306:Risk
chemical_list: D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D002121:Calcium Channel Blockers