To evaluate the effect of drug interaction between omeprazol and clopidogrel in hospital readmission of patients with acute coronary syndrome (ACS).Case-control study.University Clinic LeonXIII, Medellin, Colombia.We selected from a prevalent population, between 2009-2010, use of clopidogrel patients on an outpatient basis (less than one year and more than 30days), and hospital stay for ACS or the presence of a previous ACS.A case-patient was defined as one who had a recurrence of ACS and a patient-control is defined as one that no recurrence of ACS. Both groups used ambulatory prior clopidogrel due to ACS. As defined risk factor the joint use of omeprazole and clopidogrel outpatients.During the study, 1680patients clopidogrel formulated. This group identified 50cases readmitted with ACS and 76controls. No statistically significant association was found between use of clopidogrel-omeprazole and increased risk of hospital readmission for ACS (OR: 1.05; 95%CI: 0.516-2.152; P=.8851).In this small group of patients with previous SCA, the simultaneous use of clopidogrel with omeprazole does not increase the risk of a readmission by recurrence of this type of coronary event.