What should a doctor consider before giving a patient metoprolol for heart palpitations due to too much adrenaline?

An endocrinologist. B"sd It is essential to define the nature and source of the excess "adrenaline", which usually refers to normetanephrine (NE) and less commonly but much more dangerous epinephrine (E). Metoprolol is a selective beta blocker which can counter the effects of excess NE. However, E is both beta and alpha. In conditions of E excess metoprolol can result in paradoxical severe hypertension emergency.