Tell your doctor about all your current medicines. Many drugs can interact with metoprolol, especially:
any other heart or blood pressure medications;
epinephrine (Epi-Pen);
an antidepressant;
an ergot medicine--dihydroergotamine, ergonovine, ergotamine, methylergonovine; or
an MAO inhibitor--isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, tranylcypromine.
This list is not complete and many other drugs may interact with metoprolol. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.
 Metoprolol drug interactions (more detail)
