Final answer:
Sympathetic blockers, such as β-blockers, are used to treat hypertension by preventing adrenaline from increasing heart rate and causing vasoconstriction, hence lowering blood pressure.
Step-by-step explanation:
To treat hypertension, sympathetic blockers are commonly used rather than sympathetic stimulators. The rationale behind using sympathetic blockers is to counteract the effects of the sympathetic nervous system, which include vasoconstriction and increased heart rate - both of which can raise blood pressure. Medications such as β-blockers, including metoprolol and propranolol, mitigate these effects by blocking β-receptors associated with these sympathetic actions.
As a result, these drugs are able to promote vasodilation and lower heart rate making them effective treatments for hypertension. Specifically, β-blockers function by antagonizing the stimulatory effect of adrenaline on the heart and the blood vessels. Through blocking the G-protein-linked receptors in the heart muscles β-blockers prevent adrenaline from increasing heart rate and causing vasoconstriction thus reducing blood pressure. Additionally, other sympatholytic drugs such as α-blockers work on different receptors within the sympathetic nervous system to provide similar benefits in treating cardiovascular conditions.