Final answer:
Beta blockers are used to block the beta-receptors associated with vasoconstriction and cardioacceleration in hyperthyroidism. They can help reduce symptoms until definitive treatment is provided.
Step-by-step explanation:
Beta blockers are used to blunt adrenergic manifestations of hyperthyroidism while awaiting definitive treatment because they block the beta-receptors associated with vasoconstriction and cardioacceleration.
By blocking these receptors, beta blockers can help reduce symptoms such as increased heart rate, tremors, and anxiety that are characteristic of hyperthyroidism. They are not a definitive treatment for hyperthyroidism but can provide temporary relief until the underlying cause is addressed.