Acute Myocardial Infarction from Coronary Vasospasm Precipitated by Pseudoephedrine and Metoprolol Use.

Pseudoephedrine is a sympathomimetic α- and β-adrenergic receptor agonist that causes vasoconstriction and reduction in edema throughout the nasal passages. Coronary vasospasm associated with pseudoephedrine has been reported in the literature. We discuss the case of a patient with new-onset atrial fibrillation receiving metoprolol for rate control on a background of pseudoephedrine use for allergic rhinitis leading to acute myocardial infarction from multivessel coronary vasospasm. This case illustrates the importance of understanding the pharmacology of potential drug-drug interactions when managing patients with acute cardiovascular syndromes.