small animal - alpha 2 agonists

Question 1

what is the alpha 2 agonist used in SA?

Answer 1

dexmeditomidine

Question 2

what is the dose of dexmedetomidine (IM, SQ, IV)?

Answer 2

0.001-0.02 mg/kg

Question 3

Effects of alpha 2 agonists?

Answer 3

1. suppression of norepi release by neg feedback
2. transient HYPERtension followed by sustained hypotension
3. vasoconstriction of arteries and veins (vascular smooth muscle)
4. decreased gut motility
5. inhibition of lipolysis
6. sedation
7. analgesia
8. inhibition of INSULIN release from pancreas
9. platelet aggregation

Question 4

advantages of dexmedetomidine - 5

Answer 4

1. powerful sedative
2. powerful analgesia (200x potency of xylazine)
3. good muscle relaxation
4. significantly decreases requirement for other general anesthetics by 30-60% (dose dependent)
5. minimal resp depression

Question 5

disadvantages of dexmedetomidine -

Answer 5

1. peripheral vasoconstriction
2. profound bradycardia
3. decreased CO
4. do NOT use in preexisting CV Dz pts
5. don’t use anticholinergics for bradycardia - increasing heart rate in the face of vasoconstriction and hypertension may overwork the heart, without actually improving cardiac output, and can cause malignant arrhythmias