Premedication 3 - Opioids and Muscle Relaxants

Question 1

Which drug group are the strongest available analgesics?
A) benzodiazepines
B) Alpha 2 agonists
C) Anticholinergics
D) Opioids

Answer 1

D - opioids

Question 2

T/F: opioids have minimal CV side effects and are suitable for most risk patients

Answer 2

True

Question 3

A more potent drug requires

Answer 3

less dose for the same effect

Question 4

3 classifications of opioids

Answer 4

Full agonists
Partial agonists
antagonists

Question 5

Full opioid agonists

Answer 5

activate receptors and trigger full tissue response

Question 6

Partial opioid agonists

Answer 6

activate receptors but do not trigger a full tissue response even at high doses

Question 7

opioid antagonists

Answer 7

bind to receptors but do not trigger detectable tissue response

Question 8

CNS effects of opioids

Answer 8

analgesia - excellent for acute pain
decrease MAC inhalants
sedation (depends on species and pain level)
excitation, dysphoria
tolerance
dependence

Question 9

T/F: all opioids trigger vomiting

Answer 9

false, they can trigger or inhibit vomiting

Question 10

MoA of vomiting from opioids

Answer 10

water soluble opioids (morphine) enter brain slowly = cause vomiting
lipid soluble opioids (fentanyl) enter brain fast = no vomiting

Question 11

Which of the following is FALSE regarding the CV effects of opioids?
A) suitable for most risk patients because no direct CV effects
B) improves CV function because allows reduction of anesthetic dose
C) may decrease HR and BP because reduction of sympathetic tone and increase of parasympathetic tone
D) treat the tachycardia with atropine

Answer 11

D - you would treat the bradycardia with atropine (opioids don’t cause tachycardia)

Question 12

Resp effects of opioids?

Answer 12

resp depression
antitussive
may inhibit protective reflexes (coughing)

Question 13

GI effects of opioids

Answer 13

defecation
obstipation
spasm of hepatic-pancreatic sphincter (Oddi)

Question 14

Important other effects of opioids

Answer 14

hypothermia
post OP hyperthermia in cats
myosis (dogs), mydriasis (cats)
inhibition of urination
noise sensitivity

Question 15

3 indications of opioid use

Answer 15

premedication
perioperative analgesia
treatment of acute and chronic pain

Question 16

Describe important info about Morphine

Answer 16

cheap and strong analgesic, water soluble
causes vomiting
slow onset, long duration
metabolized in liver to an active metabolite
may cause histamine release
duration of epidural analgesia: 12-24h

Question 17

Describe important info about Fentanyl

Answer 17

strong analgesic (full u agonist)
fast onset, short duration
no histamine release
may accumulate after long infusion

Question 18

Boluses of remifentanil can cause sudden _______

Answer 18

bradycardia

Question 19

Describe butorphanol

Answer 19

antagonist on u and agonist on k receptors
weak and short acting analgesic
may antagonize full u agonists

Question 20

Describe buprenorphine

Answer 20

partial u agonist
stronger than butorphanol but weaker than full u agonists
long acting
given to cats because less excitation than full u agonists

Question 21

Describe Tramadol

Answer 21

PO
weak analgesic
inhibits NE and serotonin reuptake
metabolized in the liver, its metabolite is u opioid agonist

Question 22

You are performing surgery on a dog and have given it buprenorphine as an analgesic. You are noticing severe respiratory depression. Which opioid antagonist could you give to reverse the respiratory depression?

Answer 22

Naloxone

Question 23

______ is used to antagonize wild animals after long acting opioids

Answer 23

Naltrexone

Question 24

Centrally acting muscle relaxant

Answer 24

Guaifenesin

Question 25

T/F Guaifenesin is excellent for analgesia and sedation in large animals

Answer 25

False, is a muscle relaxant that offers no analgesia or unconsciousness

Question 26

> 10% Guaifenesin can cause

Answer 26

thrombophlebitis or hemolysis

Question 27

What is triple dip

Answer 27

GG + a2 agonist + ketamine

Question 28

T/F: guaifenesin improves muscle relaxant effects of other premed drugs

Answer 28

True