Lecture 2 8/22/24

Question 1

What are the reasons for providing pre-medication prior to induction?

Answer 1

-facilitate handling
-have a smooth induction
-decrease dose of induction and maintenance drugs
-reduce adverse effects of induction and maintenance drugs
-improve/provide preemptive analgesia
-decrease airway secretions
-improve quality of recovery

Question 2

What is a tranquilizer?

Answer 2

drug that relieves anxiety without causing major sedation

Question 3

What is a sedative?

Answer 3

drug that relieves tension and anxiety, allowing sleep

Question 4

What is neurolept analgesia?

Answer 4

combination of neurolept and analgesic

Question 5

What are the properties of neurolepts?

Answer 5

-inhibition of emesis
-inhibition of motor activity and arousal

Question 6

What are the components of dissociative anesthesia?

Answer 6

-analgesia
-amnesia
-catalepsy (paralysis with motor and sensory failure)

Question 7

What is balanced/multimodal anesthesia?

Answer 7

using drugs/methods that act through different mechanisms/receptors

Question 8

What are the components of balanced anesthesia?

Answer 8

-sedation or unconsciousness
-muscle relaxation
-analgesia
-amnesia

Question 9

Which drug classes are considered sedatives/tranquilizers?

Answer 9

-phenothiazines
-butyrophenones
-benzodiazepines

Question 10

Which drug classes are considered analgesics?

Answer 10

-alpha-2 adrenoceptor agonists
-opioids

Question 11

What are the characteristics of acepromazine?

Answer 11

-commonly used in healthy animals
-not a potent sedative
-decreases minimum alveolar concentration of volatile drugs

Question 12

What is the receptor activity of acepromazine?

Answer 12

blocks dopamine receptors; dopamine has important role in motor activity

Question 13

What are the physiological effects of acepromazine?

Answer 13

-mild tranquilizing effect
-decreases involuntary movements/reflexes
-anti-histaminic
-anti-emetic
-reduces risk of arrhythmias
-vasodilation
-hypothermia
-penile paralysis
-antipyretic

Question 14

What are the clinical uses of acepromazine?

Answer 14

-tranquilization
-premedication prior to GA
-recovery from GA/smooth process

Question 15

What are the characteristics of acepromazine for clinical use?

Answer 15

-mild muscle relaxation
-no analgesia
-slow onset
-sedation persists for several hours
-metabolized by liver

Question 16

What are the considerations when dosing acepromazine?

Answer 16

-clinical doses are much lower than label doses
-higher doses do not increase depth of sedation
-higher doses DO prolong sedation and increase adverse effects
-no reversal agent

Question 17

What is the most commonly used drug class in vet med?

Answer 17

alpha-2 adrenergic drugs

Question 18

What are the characteristics of alpha-2 adrenergic drugs?

Answer 18

-dose dependent effects
-reliable sedation
-effective analgesia
-reversible
-effective in most species
-administered IM, IV, epidural, or transmucosal

Question 19

What are the clinical uses of alpha-2 adrenergics?

Answer 19

-sedation
-analgesia
-premedication prior to GA
-recovery from GA

Question 20

What are the physiological effects of alpha-2 agonists?

Answer 20

-decreased MAC of volatile anesthetics
-visceral and somatic analgesia
-initial hypertension combined with bradycardia
-later vasodilation and decreased contractility and cardiac output
-increased urine output
-decreased GI motility
-hyperglycemia
-uterine contraction in late pregnancy
-resp. depression
-decrease in surgical stress (good)

Question 21

What are the advantages of alpha-2 agonists?

Answer 21

-small volume
-reversible
-compatible with most drugs
-analgesia
-dose-dependent sedation
-decreased MAC
-block stress response
-can induce emesis

Question 22

What are the disadvantages of alpha-2 agonists?

Answer 22

-cardiovascular effects
-decreased GI motility
-emesis
-diuresis
-hyperglycemia
-respiratory adverse effects

Question 23

What are the characteristics of alpha-2 adrenoceptor antagonists?

Answer 23

-reverse over-sedation or cardiovascular adverse effects
-less selective antagonists
-can lead to hypotension and tachycardia

Question 24

What are the characteristics of atipamezole/antisedan?

Answer 24

-most selective antagonist
-primarily for dexmedetomidine
-can be used to reverse other alpha-2s

Question 25

What are the adverse effects of alpha-2 antagonist overdose?

Answer 25

-neurological; excitement and tremors -cardiovascular; hypotension and tachycardia -GI; salivation and diarrhea

Question 26

What is the preferred administration route for alpha-2 adrenoceptor antagonists?

Answer 26

IM

Question 27

What are the characteristics of benzodiazepine function?

Answer 27

-GABA receptor agonists -enhance binding between GABA and receptor to open chloride channels -hyperpolarization inhibits cell function

Question 28

What are the clinical effects of benzodiazepines?

Answer 28

-sedation/anxiolysis -muscle relaxation -anticonvulsant -retrograde amnesia -minimal CV and resp. side effects

Question 29

In which animals do benzos have better effects?

Answer 29

debilitated or old dogs and cats

Question 30

What are the characteristics of diazepam?

Answer 30

-water insoluble -IM administration is irritating and has unpredictable absorption -IV administration must be done slowly to avoid adverse effects -sensitive to light -adheres to plastic -highly protein bound -highly lipid soluble

Question 31

What is diazepam used for?

Answer 31

-co-induction muscle relaxant -neuroleptic anesthesia induction -sedation/induction in debilitated and/or high risk animals

Question 32

What is midazolam used for?

Answer 32

-sedative and muscle relaxant effects -sedation in ruminants/pigs

Question 33

What are the characteristics of midazolam?

Answer 33

-water soluble -can be administered IM with no pain -can be mixed with other drugs -lipid soluble after injection -light sensitive -shorter duration of action compared to diazepam

Question 34

What are the characteristics of zolazepam?

Answer 34

-only found in telazol -mixed with tiletamine -combination is used for premedication and as anesthetic -longer duration of action -longer recovery time

Question 35

What is flumazenil?

Answer 35

benzodiazepine antagonist

Question 36

What are the characteristics of flumazenil?

Answer 36

-binds to GABA receptor -rarely needed clinically -reverses benzo overdose

Question 37

What is the role of anticholinergics?

Answer 37

block the action of Ach at muscarinic receptors

Question 38

What are the clinical effects of anticholinergics?

Answer 38

-increase heart rate and enhance AV conduction -bronchodilation -decrease salivary and GI secretions -decrease peristalsis

Question 39

What are the characteristics of atropine sulfate?

Answer 39

-intense effect on heart rate -first line of treatment for severe bradycardia -shorter duration of action than glyco -rabbits are resistant and need higher doses -can be given IM, IV, SQ, IT

Question 40

What are the possible adverse effects associated with atropine crossing the BBB?

Answer 40

-excitement/delirium -blindness -hyperthermia -redness -bladder distension and/or no urge to urinate

Question 41

What are the characteristics of glycopyrrolate?

Answer 41

-no BBB crossing and therefore no CNS signs -less intense cardiovascular effects -less likelihood of arrhythmias compared to atropine -longer acting than atropine -longer onset of action compared to atropine -given IM, IV, SQ

Question 42

When is atropine used vs glyco?

Answer 42

Atropine: increasing heart rate quickly/in emergency situation Glyco: increasing heart rate when bradycardia is not severe; premed. to decrease secretions

Question 43

What are the contraindications for anticholinergic use?

Answer 43

-hypertension -tachyarrhythmias -congestive heart failure -cardiovascular diseases that do not tolerate tachycardia -glaucoma -increased intraocular pressure