title: Cardiovascular outcomes and mortality in patients using clopidogrel with proton pump inhibitors after percutaneous coronary intervention or acute coronary syndrome.
abstract: BACKGROUND
  Recent studies have raised concerns about the reduced efficacy of clopidogrel when used concurrently with proton pump inhibitors (PPIs), but those studies may have overestimated the risk.
  
  
  RESULTS
  We studied the potential for increased risk of adverse cardiovascular events among users of clopidogrel with versus without concurrent use of PPIs in 3 large cohorts of patients > or =65 years of age, treated between 2001 and 2005. All patients had undergone percutaneous coronary intervention or had been hospitalized for acute coronary syndrome in Pennsylvania, New Jersey, or British Columbia, and subsequently had initiated treatment with clopidogrel. We recorded myocardial infarction hospitalization, death, and revascularization among PPI users and nonusers. We assessed our primary end point of myocardial infarction hospitalization or death using cohort-specific and pooled regression analyses. We entered 18 565 clopidogrel users into our analysis. On a pooled basis, 2.6% of those who also initiated a PPI versus 2.1% of PPI nonusers had a myocardial infarction hospitalization; 1.5% versus 0.9% died; and 3.4% versus 3.1% underwent revascularization. The propensity score-adjusted rate ratio for the primary end point of myocardial infarction or death was 1.22 (95% confidence interval, 0.99 to 1.51); for death, 1.20 (95% confidence interval, 0.84 to 1.70); and for revascularization, 0.97 (95% confidence interval, 0.79 to 1.21). Matched analyses generally yielded similar results.
  
  
  CONCLUSIONS
  Although point estimates indicated a slightly increased risk of myocardial infarction hospitalization or death in older patients initiating both clopidogrel and a PPI, we did not observe conclusive evidence of a clopidogrel-PPI interaction of major clinical relevance. Our data suggest that if this effect exists, it is unlikely to exceed a 20% risk increase.
authors.affiliation: Division of Pharmacoepidemiology and Pharmacoeconomics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, 1620 Tremont Street, Boston, MA 02120, USA. jrassen@post.harvard.edu
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Rassen
authors.forename: Niteesh K
authors.initials: NK
authors.lastname: Choudhry
authors.forename: Jerry
authors.initials: J
authors.lastname: Avorn
authors.forename: Sebastian
authors.initials: S
authors.lastname: Schneeweiss
mesh_terms: D054058:Acute Coronary Syndrome / Q000188:drug therapy* / Q000453:epidemiology / Q000401:mortality*; D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D002318:Cardiovascular Diseases / Q000139:chemically induced / Q000453:epidemiology / Q000209:etiology; D000077144:Clopidogrel; D015331:Cohort Studies; D016208:Databases, Factual; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000009:adverse effects; D012307:Risk Factors; D013988:Ticlopidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D016896:Treatment Outcome
chemical_list: D054328:Proton Pump Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine