Abstract
Kounis syndrome (KS) is defined as the occurrence of acute coronary syndrome due to coronary artery spasm in a patient with an allergic reaction. Antibiotics are the most common trigger for KS. In this case report, we present a 45-year-old man with HIV/AIDS who was being managed for mpox and developed chest pain and hypotension during vancomycin infusion, which was complicated by the development of ST-elevation myocardial infarction (STEMI). His left heart catheterization showed normal coronaries with the resolution of ECG changes and symptoms upon discontinuing vancomycin.