Alpha-2 Adrenergic Agents

Question 1

What is the effect of alpha 2 on pancreatic beta cells?

Answer 1

Inhibition of insulin secretion

Question 2

What is the effect of alpha 2 on platelets?

Answer 2

Aggregation

Question 3

What is the effect of alpha 2 on nerve endings?

Answer 3

Inhibition of NE synthesis

Question 4

What is the effect of alpha 2 on fat cells?

Answer 4

Inhibition of lipolysis

Question 5

What is the effect of alpha 2 on signaling intermediates and effectors?

Answer 5

Decreased cAMP

Question 6

Which drugs are alpha 2 agonists?

Answer 6

Xylazine, detomidine, medetomidine, romifidine

Question 7

Which drugs are alpha 2 antagonists?

Answer 7

Yohimbine, atipamezole, tolazoline

Question 8

Which is the most selective: Xylazine or Medetomidine?

Answer 8

Medetomidine

Question 9

In which ways can the alpha-2 agonists be administered?

Answer 9

IM & IV

Question 10

For which species is Xylazine licensed?

Answer 10

Dogs, cats, & horses

Question 11

True or False: Xylazine is a controlled substance.

Answer 11

FALSE: Xylazine is NOT a controlled substance.

Question 12

What was the first alpha-2 adrenergic agonist approved for use in veterinary medicine?

Answer 12

Xylazine

Question 13

What are the 3 therapeutic uses of alpha-2 agonists?

Answer 13

1. Sedation
2. Muscle relaxant
3. Analgesia

Question 14

What are the 3 therapeutic uses of Xylazine?

Answer 14

1. Sedation and restraint: for radiographs, bandage changes, minor laceration repairs, wound care
2. Visceral analgesia in horses
3. Pre-anesthetic: in combination with an opioid

Question 15

What 2 types of animals should NOT be given Xylazine?

Answer 15

1. Older animals

2. Patients with cardiac conditions

Question 16

For which patients should Xyaline be reserved?

Answer 16

Healthy patients

Question 17

What are the GI effects associated with Xyalzine?

Answer 17

1. Decreased GI motility

2. Emesis if not with held from food (90% of cats/10% of dogs)

Question 18

What are the renal effects associated with Xylazine?

Answer 18

Increased urine output

Question 19

How does Xylazine cause an increase in urine output?

Answer 19

Via suppression of anti-diuretic hormone release centrally

Question 20

What are the uterine effects associated with Xylazine?

Answer 20

Increased contraction, leading to premature delivery in pregnant animals (oxytocin-like)

Question 21

What are the respiratory effects associated with Xylazine?

Answer 21

1. Minor hypoxemia in cattle and sheep
2. Bronchoconstriction
3. Pulmonary edema
4. Increased airway resistance

Question 22

True or False: Xylazine causes an increase in insulin release from the pancreas.

Answer 22

FALSE: Xylazine decreases plasma insulin levels

Question 23

What are 2 sequelae to the decreased plasma insulin levels?

Answer 23

1. Hyperglycemia

2. Glycosuria

Question 24

Xylazine has synergistic actions with what other class of drugs?

Answer 24

Phenothiazines

Question 25

What are 3 precautions to consider when using Xylazine?

Answer 25

1. Not recommended for use in pregnant animals 2. Monitor cardiopulmonary depression 3. Must be avoided with cardiovascular, liver, and kidney diseases

Question 26

Which of the following is most susceptible to Xylazine toxicity: horse, ruminant, cat, or dog?

Answer 26

Ruminant

Question 27

What is the most potent alpha-2 agonist?

Answer 27

Medetomidine

Question 28

Medetomidine is ____ times more selective than Xylazine.

Answer 28

10X

Question 29

Which of the following can cause profound ataxia in horses at high doses: Xylazine or Medetomidine?

Answer 29

Medetomidine

Question 30

What are the 3 alpha-2 antagonist?

Answer 30

1. Yohimbine 2. Atipamexole 3. Tolazoline

Question 31

What is the primary use for Yohimbine?

Answer 31

Reverse the sedative effects of Xylazine following short surgical procedures.

Question 32

There are 6 adverse effects associated with the use of Yohimbine. Name 4.

Answer 32

1. Tachycardia 2. Salivation 3. Muscle tremors 4. CNS excitement 5. Increased respiratory rate (dogs & cats) 6. Removal of alpha-2 agonist analgesia