Flashcards in Alpha 2 Agents Deck (17):
list the therapeutic benefits of Alpha 2 agonists:
sedation, analgesia, skeletal muscle relaxation
What are the major effects of xylazine on cadiovascular system?
activate peripheral alpha 2 receptors, rapid incrase in SVR, increases arterial BP
hypertension- baroreceptor mediated bradycardia
over time peripheral effects subside and the BP will return to normal
What are the major effects of xylazine on Gi/emesis
used in horses for tx colic associated pain
emesis frequently in cats; less often in dogs
What are the major effects of xylazine on renal?
increase in urine output onbserve transiently due to supression of ADH release centrally
What are the major effects of xylazine on uterine?
oxytocin like effect, dont give to cows in last trimester- abortion
What are the major effects of xylazine on respiratory?
minor hypoxia in cattle and sheep
activation of peripheral alpha-2 adrenoreceptors, leads to increase airway resistance
Adverse effects of xylazine:
synergistic actions with phenothiazines
additive effects w. CNS depressants
decrease plasma insulin levels (hyperglycemia/glycosuria)
RMTs are more sensitive to xylazine than dogs. horses, cat
What is the major clinical application of Yohimbine?
reversal agent for xylazine
adverse effect- CNS excitement, muscle tremors, salivation
What is the major clinical application of Atipamezole?
highly selective for reversal of medotomidine in dogs
What is the major clinical application of Tolazoline?
least selective antagonist
What drug is most selective for alpha 2 : alpha 1`
What drug is least selective for alpha 2: alpha 1
What is the active enantiomer of medetomine?
dexmedetomine, the other is levomedetomidine`
Alpha 2 agonist mech of action
activation of presynaptic alpha 2 receptors in CNS/PNS
post junctional alpha 2
results in decrease in sympathetic outflow
decrease in catecholamines
sedation, analgesia, and skeletal muscle relaxation
Where are the receptors that mediate sedation via alpha 2 agonists?
primarily in the locus coeruleus on the pons and lower brain stem- block NE release
What species is the most sensitive to alpha 2 agonism?
RMTs > cats/dogs > pigs