Journal of General Internal Medicine

, Volume 28, Issue 2, pp 216–222

Gastrointestinal Events with Clopidogrel: A Nationwide Population-Based Cohort Study

  • Erik Lerkevang Grove
  • Morten Würtz
  • Peter Schwarz
  • Niklas Rye Jørgensen
  • Peter Vestergaard
Original Research

DOI: 10.1007/s11606-012-2208-0

Cite this article as:
Grove, E.L., Würtz, M., Schwarz, P. et al. J GEN INTERN MED (2013) 28: 216. doi:10.1007/s11606-012-2208-0



Clopidogrel prevents cardiovascular events, but has been linked with adverse gastrointestinal (GI) complications, particularly bleeding events.


We aimed to investigate the risk of adverse GI events in patients treated with clopidogrel.


A nationwide population-based cohort study based on linkage of three administrative registries in Denmark.


All individuals who redeemed at least one prescription of clopidogrel from 1996 to 2008 were included as exposed subjects (n = 77,503). For each exposed subject, three matched controls were randomly selected from the background population (n = 232,510).


Follow-up began on January 1, 1996, and was censored on December 31, 2007, or if patients emigrated or died. The study endpoint was the occurrence of any gastritis, GI ulcer or bleeding. Analyses were adjusted for comorbidity and medication.


Regardless of dose, adjusted odds ratios associating clopidogrel use with the study endpoint were statistically significant and followed a dose–response pattern. The crude absolute risk of GI events were: never users: 2.2 %; <0.1 defined daily dose (DDD) of clopidogrel per day: 7.1 %; 0.1–0.39 DDD: 6.0 %; 0.4–0.79 DDD: 5.7 %; ≥0.80 DDD: 4.4 %. Adjusted odds ratios were: <0.1 DDD: 1.34, 95 % CI: 1.26–1.42; 0.1–0.39 DDD: 1.58, 95 % CI: 1.48–1.68; 0.4–0.79 DDD: 1.91, 95 % CI: 1.77–2.06; ≥0.80 DDD: 1.77, 95 % CI: 1.66–1.89, all p-values < 0.01. Depending on the dose, numbers needed to harm ranged from 58 to 33 patients receiving 12 months of clopidogrel treatment.


The well-known cardioprotective effect of clopidogrel must be carefully weighed against an increased risk of GI events.


clopidogrelcoronary artery diseasegastritisgastrointestinal hemorrhagestomach ulcer



Adenosine diphosphate


Anatomical Therapeutical Chemical


Defined daily dose




International Classification of Diseases

Copyright information

© Society of General Internal Medicine 2012

Authors and Affiliations

  • Erik Lerkevang Grove
    • 1
  • Morten Würtz
    • 1
  • Peter Schwarz
    • 2
    • 3
  • Niklas Rye Jørgensen
    • 2
  • Peter Vestergaard
    • 4
  1. 1.Department of CardiologyAarhus University Hospital, SkejbyAarhusDenmark
  2. 2.Research Center of Aging and Osteoporosis, Departments of Medicine and DiagnosticsCopenhagen University HospitalGlostrupDenmark
  3. 3.Faculty of Health SciencesCopenhagen UniversityCopenhagenDenmark
  4. 4.Medical FacultyAalborg UniversityAalborgDenmark