2- Types of premeds

Question 1

List the 6 drug groups of pre-medications

Answer 1

Opioids
Alpha-2 agonist
Phenothiazines
Benzodiazepine
NMDA Receptor antagonists
Anticholinergics

Question 2

Give 3 examples of an opiod

Answer 2

Methadone
Fentanyl
Pethidine
Buprenorphine
Butorphanol

(Morphine - but not licensed)

Question 3

Why is an opioid included in a pre-med?

Answer 3

Provide sedation & analgesia

Question 4

What are the 4 receptors opioids act at?

Answer 4

MU
Kappa
Delta
Nociception

Question 5

What receptors does butorphanol act at and What is its limitation?

Answer 5

MU antagonist & Kappa agonist

Provides good sedation but is has poor and short-lived analgesia

Would be ideal for non-painful procedures

Question 6

T/F Methadone and Fentanyl are Full MU agonsits

Answer 6

True

Question 7

Which types of opioids have the most analgesic effects

Answer 7

Full Mu agonists
methadone, fentanyl, pethidine and morphine

Question 8

What effect does an opioid have on the GI system?

Answer 8

Reduce motility & decreases gastric emptying

Question 9

What effects do opioids have on cardiovascular system

Answer 9

cause minimal cardiovascular depression and are often used in very sick patients

Question 10

What drug antagonises opioids?

Answer 10

Naloxone

Question 11

Give 2 examples of an alpha-2 agonist

Answer 11

Medetomidine
Dexmedetomidine
Xylazine
Detomidine
Romifidine

Question 12

Which alpha-2 agonists are most commonly used in small animal practice

Answer 12

Medetomidine and dexmedetomidine

Question 13

Why is xylazine less commonly used in small animals?

Answer 13

Poor affinity for alpha 2- receptors thus more side effects

Question 14

What is the aim of an alpha-2 agonist?

Answer 14

Profound dose dependant sedation & good analgesia (short-lived)

Question 15

What is detomidine licensed for

Answer 15

is licenced in horses and cattle

Question 16

What effect do alpha-2 agonists have on the liver?

Answer 16

reduced blood flow to the liver & hepatic metabolism , shouldn’t use it in liver disease patients

Question 17

Alpha 2 agonists have significant effects on what system?

Answer 17

Cardiovascular

Question 18

Why wouldn’t you use an alpha 2 agonist in a unstable diabetic patient?

Answer 18

Reduces endogenous insulin secretion = causes transient hyperglycaemia

Question 19

What drug do you use to antagonise an alpha-2 agonist?

Answer 19

Atipamezole

Question 20

What effect does alpha-2 agonist have on MAC

Answer 20

They have marked drug sparing effects
they reduce MAC and therefore the amount of inhalation agent required and the amount of induction agent.

Question 21

What can alpha-2 agonist do in cats

Answer 21

They can cause emesis, particularly in cats if used alone

Question 22

What is the only licensed phenothiazine? & what is its aim?

Answer 22

Acepromazine (ACP) - contributes to sedation & provides anxiolytics

NO ANALGESIC PROPERTIES

Question 23

What receptors do phenothiazines work out?

Answer 23

Centrally acting by antagonising D1/D2 receptor

Also act on alpha-1 muscarinic & H1 receptors

Question 24

What role does alpha-1 antagonism have on blood vessels? & why is this a problem with phenothiazines

Answer 24

Vasodilation

Antagonise alpha 1 receptors = use causes vasodilation causing hypotension & hypothermia

Also can’t antagonise this drug which means this effect can be difficult to manage

Question 25

How long does it take for phenothiazines to take effect

Answer 25

relatively slow to effect taking about 30-40 minutes when administered by IM injection and lasts about 6-8 hours in healthy animals

Question 26

Define Neuroleptanalgesia

Answer 26

is the combination of an opioid and a tranquilizer or sedative and reduces the amount of each required and results in improved sedation. So this is what you’d get if you combined an opioid and acepromazine.

Question 27

List the 2 Benzodiazepines and what animals they are licensed in

Answer 27

Midazolam (horses) & Diazepam (Dogs/cats)

Question 28

What receptor do benzo's work at?

Answer 28

GABA-A receptor

Question 29

What is the aim of benzos?

Answer 29

Anxiolysis, sedation & hypnosis (Not an analgesic) The degree of sedation is poor - not something you'd give to healthy patient. Good for sicker patients as minimal resp and cardio depression

Question 30

Benzos are also used for..

Answer 30

seizing patients as they are anti-convulsants

Question 31

What is the antagonist called for benzodiazepines?

Answer 31

Flumazenil

Question 32

What drug class is Ketamine under?

Answer 32

NMDA receptor antagonists

Question 33

At high doses ketamine is a ...

Answer 33

Dissociative anaesthetic

Question 34

At low doses ketamine results in...

Answer 34

Sedation

Question 35

When ketamine is used alone it is a poor.....thus we combine it with....

Answer 35

Muscle relaxant = Miadazolam(benzo) or alpha 2

Question 36

How long does ketamine tend to last

Answer 36

It’s relatively short acting (30-45 minutes)

Question 37

What effects do anticholinergics have?

Answer 37

Reduce bradycardia, respiratory tract secretions

Question 38

Name some examples of anticholinergics

Answer 38

Atropine, Glycopyrrolate

Question 39

What are the side effects of anticholinergics in the premed

Answer 39

mydriasis, reduced gut motility, bronchodilation etc. so not routinely used in premed

Question 40

What Is alfaxalone?

Answer 40

Neuroactive steroid

Question 41

What type of receptors do birds have a high proportion of

Answer 41

kappa receptors means that butorphanol which is a MU agonist and kappa agonist could be a good choice for pre-med in birds

Question 42

Which animals should alpha-2 agonists not be used in

Answer 42

need to be careful in blocked animals sick animals due to cardio effects unstable diabetics