Sedatives

Question 1

What is a sedative?

Answer 1

A drug that makes you calm, drowsy and not very responsive to external stimuli

Question 2

What does high sedation cause?

Answer 2

Sleep, but can be roused (unlike anaesthesia)

Question 3

What are the types of sedation?

Answer 3

Neuroleptic

Neuroleptanalgsia

Question 4

What is neuroleptic sedation?

Answer 4

Sedation with effects of phenothiazines or butyrophenones on the CNS

Question 5

What is neuroelepotanalgesia?

Answer 5

Combination of a neuroleptic and an opioid

Question 6

What is tranquilliser?

Answer 6

Makes you calm, but alert and responsive

Question 7

What does a high dose of tranquilliser cause? What is this?

Answer 7

Catalepsy

Altered state of consciousness, can be hyper

Question 8

What is an anxiolytic?

Answer 8

Drug that reduces anxiety, makes calm

Normal stressful responses doesn’t result in stress response (increased cortisol)

Question 9

What are the 4 classes of sedatives?

Answer 9

Alpha 2 agonists
Phenothiazines
Butyrophenones
Benzodiazepines

Question 10

Which classes of sedatives are licensed?

Answer 10

All except benzodiazepines

Question 11

How do alpha 2 agonists work? What do they cause?

Answer 11

Bind to a2 receptors
Cause sympathomimetic peripheral effects (e.g. vasoconstriction)
Cause sympatholytic CNS effects (e.g. sedation)

Question 12

How are alpha 2 agonists administered?

Answer 12

Water soluble injection so IV or IM

Molecules lipid soluble so can be orally, SC or epidural

Question 13

What are the main effects of alpha 2 agonists?

Answer 13

Sedation, analgesia (1/3 of sedation duration), muscle relaxation
= anaesthetic sparing agent

Question 14

What are the side effects of alpha 2 agonists?

Answer 14

Vasoconstriction causes increased after load on heart
Diuresis
Hyperglycaemia
Muscle relaxation 
Sweating

Question 15

What are the advantages to alpha 2 agonists?

Answer 15

Analgesic for some of anaesthetic = anaesthetic sparing agent
Has antagonist available

Question 16

Atipamezole is the antagonist to alpha 2 agonists. What is a disadvantage of using this antagonist?

Answer 16

Antagonises all effects including analgesia

Overdose causes excitement and hyperalgesia

Question 17

Give an example of an alpha 2 agonist

Answer 17

Romfidine

Question 18

Give an example of the only licensed phenothiazine.

Answer 18

Acepromazine

Question 19

Phenothiazines are antagonists to many receptors. Give examples of some of these receptors and what their antagonist binding causes

Answer 19

A1 adrenoreceptors - vasodilation
Dopamine receptors -sedation
Histamine receptors - anti-emetic and reduced hypersensitivity
Serotonin receptors - anxiolytic
Muscarinic (cholinergic) receptors - reduced parasympathetic tone

Question 20

How can phenothiazines be administered?

Answer 20

Water soluble injectable = IM, IV

Lipid soluble molecules = SC, orally

Question 21

Which is the least reliable route for acepromazine and why?

Answer 21

Orally

Least bioavailability

Question 22

What are the effects of acepromazine/phenothiazinines?

Answer 22

Sedation (less reliable than a2 agonists)

Muscle relaxation

Question 23

What are the disadvantages of acepromazine?

Answer 23

No analgesia

No anatagonist

Question 24

What are the side effects of acepromazine/phenothiazines?

Answer 24

Vasodilation
Syncope
Antihistamine
Long lasting

Question 25

What is syncope?

Answer 25

Temporary unconsciousness Lack of blood to brain Common in brachycephalic and excited animals

Question 26

What is the MOA of butyrophenones?

Answer 26

Similar to phenothiazines - antagonist to lots of receptors

Question 27

What are the main effects of butryophenones?

Answer 27

Sedation (least reliable) Muscle relaxation Anti-emetic, anti-histamien Long lasting

Question 28

What are the side effects of butyrophenones?

Answer 28

Long lasting Vasodilation (less than acepromazine) NO ANALGESIA OR ANTAGONIST

Question 29

Give an example of a butyrophenone

Answer 29

Fluanisone | azaperone

Question 30

How do benzodiazepines work?

Answer 30

Bind to GABA receptor (inhibitory neurotraasmitter)

Question 31

Give 2 examples of benzodiazepines. Are either of these licensed?

Answer 31

Diazepam Midazolam No licensed benzodiazipin!

Question 32

Why is diazepam not used as much as midazolam?

Answer 32

IV solution expensive | Emulsion form even more expensive

Question 33

What is a side effect of benzodiazepines?

Answer 33

Causes excitement if used alone | Overdose causes excitement

Question 34

Which is the only group of sedatives to have analgesic effects?

Answer 34

Alpha 2 agonists | Only for 1/3 of sedative effect

Question 35

Which are the 2 groups of sedatives to have antagonists?

Answer 35

Alpha 2 agonists | Benzodiazepines