Beta-blockers

increase the vasoconstrictor response to epinephrine, but reduce the tachycardia resulting from epinephrine.

inhibit the vasoconstrictor response to epinephrine and levonordefrin.

should not be used with indirectly acting sympathetic drugs (i.e., Tyramine and anphetamines) and with several other drugs such as opioids, especially meperidine.

have exaggerated effects when given with neuron depleting agents like reserpine and quanethidine.