Definition of Sympatholytic:
Sympatholytic agents (adrenergic antagonists) block the neurotransmitter receptors that bind norepinepherine and epinepherine (noradrenaline and adrenaline), which are divided into several subtypes: alpha-1, alpha-2, beta-1, beta-2. Blocking these receptors generally favors a parasympathetic state. They produce physiological effects resembling those caused by the activity or stimulation of the parasympathetic nervous system. As a general rule, beta-2 antagonists sedate lung function, while beta-1 antagonists sedate heart function in order to support the vegatative parasympatheic state [ORWJr].
They block transmission of impulses from the adrenergic (sympathetic) postganglionic fibers to effector organs or tissues, inhibiting such sympathetic functions as smooth muscle contraction and glandular secretion.[Miller-Keane2003]