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The α₂ agonists (e.g. xylazine, detomidine, medetomidine, dexmedetomidine, and romifidine) are classified as sedatives/analgesics. In addition to effective sedation, these drugs produce profound analgesia and good central muscle relaxation. The α₂ agonists produce their pharmacologic effects by their actions on both the central and peripheral α₂ adrenoceptors. Stimulation of central (presynaptic) α₂ adrenoceptors inhibits the release of catecholamines, thus reducing the response to excitatory input, and as a result sedation occurs. Peripheral (postsynaptic) α₂ receptors are found in the vasculature, pancreatic islet cells, and uterine muscles. As a result, transient hypertension, hypoinsulinemia, hyperglycemia, and oxytocin‐like effect are often associated with the administration of an α₂ agonist [33]. Other side effects associated with the administration of α₂ agonists include direct myocardial depression and augmentation of parasympathetic stimulation resulting in a decrease in cardiac output, bradycardia, and hypotension. Up to a sixfold increase in urine output subsequent to a decrease in secretion of antidiuretic hormone is a common side effect of α₂ agonists. The central muscle‐relaxing effect produced by α₂ agonists is believed to be mediated through the inhibition of nerve impulse transmission at the internuncial neurons of the spinal cord, brain stem, and subcortical level of the brain [34]. Because of this, α₂ agonists are often given in combination with anesthetics that do not provide adequate muscle relaxation for surgical procedures. For example, when ketamine is administered alone, it is often associated with muscle tremors, jerking activity, and rigidity; xylazine is administered concurrently to improve the muscle relaxation during ketamine anesthesia. All α₂ agonists, though considered as pure α₂ agonists, also have affinity for α₁ receptors. The α₂ : α₁ selectivity ratios for xylazine, detomidine, romifidine, and medetomidine/dexmedetomidine are 160 : 1, 260 : 1, 340 : 1, and 1620 : 1, respectively [35, 36].