Anesthesia - Premeds

Question 1

Alpha 1 receptor location/function?

Answer 1

Vascular smooth muscle to control BP

Question 2

Alpha 2 receptor location/function?

Answer 2

Brain and periphery; modulates sympathetic outflow in brainstem

Question 3

Acepromazine drug class?

Answer 3

Phenothiazine

Question 4

Acepromazine MOA?

Answer 4

Central dopamine R antagonist

Question 5

Acepromazine reversal?

Answer 5

NONE; lasts 4-6 hours

Question 6

Acepromazine effect?

Answer 6

Decrease alertness, increase tolerance

Question 7

Acepromazine analgesic effects?

Answer 7

None

Question 8

Acepromazine side effects/other considerations?

Answer 8

Vasodilation via a1 antagonism (potential reflex increase in HR)
Transient reduction in PCV d/t fluid shifts
Non-reversible

Question 9

Acepromazine is commonly used in which species?

Answer 9

Dogs, cats, horses

Question 10

Commonly used a2 adrenergic R agonists?

Answer 10

Dexmedetomidine, xylazine, romifidine, detomidine

Question 11

Dexmedetomidine drug class?

Answer 11

a2 R agonist

Question 12

Xylazine drug class?

Answer 12

a2 R agonist

Question 13

Detomidine drug class?

Answer 13

a2 R agonist

Question 14

Romifidine drug class?

Answer 14

a2 R agonist

Question 15

Effects of alpha-2 adrenergic R agonists?

Answer 15

Sedation (rousable)
Analgesia
Anxiolysis (dec. central sympathetic tone)
Muscle relaxation
Potent drug sparing (up to 90%)

Question 16

Alpha 2 R agonist reversal?

Answer 16

Alpha-2 antagonist (yohimibine, atipamazole, or tolazoline)

Question 17

Common a2 antagonists for reversal?

Answer 17

Yohimibine
Tolazoline
Atipamazole

Question 18

What species are alpha-2’s commonly used in?

Answer 18

All domestic species

Question 19

A2 R agonist CV effects/considerations?

Answer 19

Initial vasoconstriction increases BP, reflex bradycardia, then dec. central sympathetic output further dec. HR but vasoconstriction disappates
Decreases CO
May inc. or dec. SVR over time

Question 20

Alpha-2 agonist side effects?

Answer 20

Diuresis (decreases ADH and insulin release so glucose increases –> osmotic diuresis)
Vomiting
Reduced GI motility
Vasoconstriction

Question 21

Alpha 2 species considerations?

Answer 21

Cats: may be used as an emetic drug
Sheep: pulmonary edema due to activation of pulmonary intravascular macrophages
Cattle: 10x more sensitive to xylazine than horses are

Question 22

Species considerations with xylazine?

Answer 22

Cattle require 1/10th the dose of horses

Question 23

What drug class is atropine?

Answer 23

Anticholinergic

Question 24

Commonly used anticholinergics?

Answer 24

Atropine and glycopyrrolate

Question 25

What species are anticholinergics used as a premed in?

Answer 25

Dogs and cats

Question 26

Anticholinergics MOA?

Answer 26

Muscarinic acetylcholine R antagonists (parasympatholytics, dec. vagal tone)

Question 27

Effects of anticholinergics?

Answer 27

Inc HR Bronchodilation Dec. secretions (oral, GI) Dec. GI motility Mydriasis

Question 28

Anesthetic properties of anticholinergics?

Answer 28

None

Question 29

Analgesic properties of anticholinergics?

Answer 29

None

Question 30

What happens if you give an a2 R agonist and an anticholinergic together?

Answer 30

a2 casues high SVR/high BP, anticholinergic increases heart rate

Question 31

What benzodiazepines are commonly used?

Answer 31

Diazepam and midazolam

Question 32

Benzodiazepine MOA?

Answer 32

GABA R agonist (GABA: inhibitory neurotransmitter in CNS)

Question 33

Benzo analgesic effects?

Answer 33

None

Question 34

Do benzos have sedative effects?

Answer 34

Sometimes - small ruminants, calm pet pigs, sick dogs/cats, and neonates of most species

Question 35

Effects of benzodiazepines?

Answer 35

Anxiolytic Amnesic Anticonvulsant Muscle relaxant Mild drug sparing

Question 36

Are benzos reversible?

Answer 36

Yes (flumazenil)

Question 37

Reversal agent for benzos?

Answer 37

Flumazenil

Question 38

CV/resp effects of benzodiazepines?

Answer 38

Minimal

Question 39

What drug class is gabapentin?

Answer 39

Gabapentinoid

Question 40

Gabapentin MOA?

Answer 40

Voltage gated Ca channel inhibitor - effects neurotransmitter release

Question 41

Gabapentin effects?

Answer 41

Anxiolytic, mild sedation

Question 42

Behavioral considerations of benzodiazepines?

Answer 42

Un-inhibition of behavior

Question 43

Commonly used mu opioid receptor agonists?

Answer 43

Morphine, hydromorphone, methadone

Question 44

MOR agonist behavioral effects?

Answer 44

Sedation: dog, rabbit, somewhat ruminants Euphoria: cat, horse (inc. activity, manic) Dysphoria: possible in all species

Question 45

MOR agonist CV/resp effects?

Answer 45

Minimal CV effects; dose dependent respiratory depression

Question 46

How would you reverse morphine, hydromorphone, or methadone?

Answer 46

MOR antagonist - naloxone

Question 47

MOA of morphine and hydromorphone?

Answer 47

Mu opioid receptor agonist

Question 48

Butorphanol MOA?

Answer 48

MOR antagonist, KOR agonist

Question 49

Sedative effects of butorphanol?

Answer 49

Good sedation, used for mildly uncomfortable procedures (ex. penn hip rads)

Question 50

Analgesic effects of MOR agonists vs. MOR antagonists/KOR agonists?

Answer 50

MOR agonists: analgesia for moderate - severe pain (morphine, hydro, methodone) MOR antagonists/KOR agonists: mild - mod pain (butorphanol)

Question 51

Butorphanol duration?

Answer 51

~1 hr SA ~2-4 hrs horse

Question 52

Buprenorphine MOA?

Answer 52

MOR partial agonist

Question 53

Buprenorphine duration?

Answer 53

Slow onset (~45 min), longer duration (6-8 hrs)

Question 54

Reversability of buprenorphine?

Answer 54

Difficult due to high affinity for MOR