The case of a 76-year-old woman who consulted the emergency room for angina of four hours of evolution and an episode of hematemesis which had also occurred the previous week is presented. She was admitted with tachycardia, hypertension, and mucocutaneous pallor. The electrocardiogram on admission showed ST depression in the lateral and inferior wall, the initial troponin was negative with a positive control, and the complete blood count showed severe anemia without involvement of the other cell lines. Management was started with omeprazole in continuous infusion for 72 hours and two units of red blood cells were transfused. Subsequently, a digestive endoscopy was performed, which showed a bleeding Dieulafoy lesion that was treated with sclerotherapy. One week later, she underwent coronary angiography with stent implantation in the left anterior descending artery, and dual antiplatelet therapy with aspirin and clopidogrel was started. After the procedure, she had new episodes of angina and required two coronary angiograms that demonstrated acute and recurrent thrombosis in the stent of the intervened artery, with failed interventions, development of cardiogenic shock, and finally death. Clinical relevance: We present the case of a patient with concomitant use of high-dose intravenous omeprazole and clopidogrel. Possible interactions between these two drugs that may have contributed to the adverse outcomes in the patient are discussed.