Lecture 9

Question 1

Define the term sedation:

Answer 1

a level of central nervous system depression that facilitates clinical activity

Question 2

Explain the mechanism of action of benzodiazepines:

Answer 2

They act as GABA agonists depressing central nervous system depression. They cause the inside of the neutron to become more negatively charged than the outside making them harder to active and thus has made it become inhibited

Question 3

What is an example of a benzodiazepine?

Answer 3

diazepam, midazolam

Question 4

Explain the mechanism of action of neuroleptics:

Answer 4

Neuroleptics are dopamine antagonists. Dopamine is used for brain reward pathways including motivation, purposefulnes and movements. The neuroleptics are also antagonists at other receptors e.g. alpha-1 adrenergic receptors.

Question 5

Explain the mechanism of action of opioids

Answer 5

The opioids work on opioid receptors. u(mu ) and k(kappa) primarily. The central effects include central nervous system depression that causes sedation. The peripheral effects include actions on Ca and K channels to decrease the ascending pain pathways.

Question 6

What is the effect of alpha-2-agonists?

Answer 6

The alpha-2-agonists are sedative by decreasing the central concentrations of NAdr. The a2 agonists bind to the a2 receptor and induces the auto-regulatory inhibitory feedback mechanism to decrease the release of NAdr. The major central effects of NAdr include altertness, arousal and pain perceptions the a2 agonist ultimately leads to sedation and analgesia.

Question 7

What are some examples of alpha-2 agonists?

Answer 7

Medetomidine and dexmedetomidine: small animals
Detomidine and xylazine: horses
Xylazine: ruminants

Question 8

What are the CVS effects of Benzodiazepines?

Answer 8

Virtually none

Question 9

What are the CVS effects of Opiods?

Answer 9

minimal - well suited for pain relief during shock

Question 10

What are the CVS effects of neuroleptics?

Answer 10

vasodilation through effects on alpha1-receptors causing hypotension

Question 11

What are the CVS effects of alpha-2-agonists?

Answer 11

1. peripherally mediated (alpha-2 receptors in blood vessels) strong short lived vasoconstriction
2. IV infusion causes increased blood pressure
3. IV bolus causes increased and then decreased BP
4. Bradycardia

Question 12

Name a benzodiazepine antagonist and common on the necessity of having one:

Answer 12

Flumazenil - almost never needed due to the safety of this class of drug

Question 13

Name an opioid antagonist:

Answer 13

Naloxone- antagonist at all opioid receptor types

Question 14

Name an alpha-2 antagonist:

Answer 14

Atipamezole (medetomidine and dexmedetomidine) is highly effective and rapidly acting
Yohimbine (for xylazine) less effective

Question 15

Name a neuroleptic antagonist:

Answer 15

No reversal agent available

Question 16

Name a side effect of the Benzodiazepines:

Answer 16

• disinhibition - need to be aware of fear biters

- excellent anti-convulscent

Question 17

Name a side effect of Acepromazine in horses:

Answer 17

penis prolapse

Question 18

Name a side effect of Opioids:

Answer 18

respiratory depression

Question 19

Name a side effect of Alpha-2 agonists:

Answer 19

• risk of absorption in third trimester

- decreased thermoregulation