Final answer:
Norepinephrine, a sympathomimetic agent, is used to treat low blood pressure by causing vasoconstriction and increasing blood pressure, unlike ß-blockers like metoprolol and propranolol which are used for high blood pressure by relaxing blood vessels and slowing heart rate.
Step-by-step explanation:
An adrenergic drug commonly used to treat low blood pressure is norepinephrine, which is also known as noradrenaline. Norepinephrine is a sympathomimetic agent that acts on alpha-adrenergic receptors to induce vasoconstriction, which in turn raises blood pressure. This is in contrast to ß-blockers, such as metoprolol and propranolol, which are typically used to manage high blood pressure and other cardiovascular conditions by blocking ß-receptors associated with vasoconstriction and cardioacceleration. While ß-blockers allow blood vessels to relax and slow down the heart rate, sympathomimetic drugs like norepinephrine work to constrict blood vessels and increase blood pressure in patients experiencing hypotension.
It's important to note that while ß-blockers are indicated for high blood pressure and heart failure, they are not used for treating low blood pressure. Instead, drugs that stimulate the adrenergic system are used, such as norepinephrine, which can be administered as an IV drip during acute hypotensive episodes.