Analgesics- Opioids

Question 1

_______________ are a group of mainly synthetic agents that act at opioid receptors to proceed analgesic and other effects

Answer 1

Opioid drugs

Question 2

Naturally occurring drugs extracted from opium

Answer 2

Opiates

Question 3

Analgesia and stupor bordering on general anesthesia

Answer 3

Narcosis

Question 4

Analgesia and amnesic state produced by admin of a neuroleptic and narcotic

Answer 4

Neurleptanalgesia

Question 5

What parts of the pain pathways do opioids have an effect on

Answer 5

Transduction
Modulation
Perception

Question 6

What are the 3 types of opioid receptors

Answer 6

Mu (u)
Kappa (k)
Delta

Question 7

What are the most common opioid receptors

Answer 7

Mu

Question 8

What is the MOA of opioid agonists

Answer 8

Activation of Mu
Couples with G protein
Reduces neurotransmitter release by decreasing Ca influx

Question 9

What are the main sites where opioid agonists inhibit neurotransmitter

Answer 9

Dorsal horn of spinal cord

Question 10

What is the distribution of opioids?

Answer 10

Widely distributed

Can cross BBB and placenta

Question 11

How are opioids metabolized?

Answer 11

Conjugation to glucuronic acid

Cats are deficient –> metabolize more slowly

Question 12

What are the full opioid Mu receptor agonists?

Answer 12

Morphine 
Hydromorphone 
Oxymorphone 
Fentanyl 
Carfentanil/Etorphine

Question 13

What is a risk of using opioids especially in dogs with IV use

Answer 13

Histamine release

Morphine > hydromorphone

Question 14

What full Mu receptor agonsit is very potent and used in wildlife

Answer 14

Carfentanil/Etorphine

Question 15

What is the partial opioid Mu receptor

Answer 15

Buprenorphine

-> semisynthetic partial u agonist
‘Ceiling effect’

Question 16

How does the onset and duration of buprenorphine compare to morphine

Answer 16

Buprenorphine has slower onset and longer duration than morphine

Question 17

What is a mixed opioid receptor agonist-antagonist

Answer 17

Butorphanol

K agonist and u antagonist
=> sedation with less analgesic effects

Question 18

What drug can be used to partially reverse the dysphroic effects from a pure Mu agonist

Answer 18

Butorphanol

Question 19

Butorphanol is better for use against (visceral/Somatic) pain?

Answer 19

Visceral

Question 20

What effects do opioids have in the CNS?

Answer 20

Behavioral changes

• CNS depression in dog, monkey, and humans
• CNS stimulation in cat, horse, ruminant, and pig

Motor activity

• depressed in dog
• increased in horse

Thermoregulation

• hypothermia in dog, rabbit and monkey
• hyperthermia in CAT, ruminant and horse

*** hyperthermia in cat-> not due to fever; can become intolerant to opioid

Question 21

What is the main effect of opioids on the respiratory system

Answer 21

Dose dependent respiratory depression -> hypoventilation

Question 22

What is the main effect of opioids on the cardiovascular system?

Answer 22

Minimal CV effects

Centrally medicated bradycardia and hypotension due to vasodilation ** most important in dogs

Question 23

What are the main GI effects of opioids

Answer 23

Nausea, salivation, vomiting, and regurgitation
-Apomorphine ->emetic of choice in dog, TOXIC to cat

Ileum and Constipation
-increased intestinal wall tone, decreased propulsive motility

Question 24

What are the clinical uses of opioid agonists

Answer 24

Analgesia

Sedation

Pre-anesthetic

Antitussive (anti cough)- non full u agonist (butorphanol)

Emetic (apomorphine)

Antidiarrheal

Question 25

When should a full/pure opioid antagonists be used?

Answer 25

``` Overdose Toxicity Severe opioid-induced respiratory depression Prolonged anesthetic recover Cardiac arrest Cardiorespiratory arrest ```

Question 26

What is a full u receptor antagonist

Answer 26

Naloxone Naltrexone and diprenorphine Methylanltrexone Reverse opioid adverse effects and analgesic

Question 27

What weak opioid u agonist also inhibits serotonin and NE reuptake

Answer 27

Tramadol Generally used for short term post-op pain management

Question 28

What semisynthetic opioid is used orally and an antitussive?

Answer 28

Hydrocodone

Question 29

What is the emetic of choice in dogs but is toxic to cats

Answer 29

Apomorphine

Question 30

What opioid has the most potent anti-diarrheal effects

Answer 30

Loperamide

Question 31

What are precautions for opioid use?

Answer 31

Pre-existing ileus Conditions causing increase ICP Advanced or severe cardiac or hypoventilation Acute renal failure/injury History of opioid intolerance/hypersensitivity

Question 32

``` Which of the following drugs MOA is described as having a 'ceiling effect' A. Morphine B. Naloxone C. Buprenorphine D. Butorphanol ```

Answer 32

C. Buprenorphine

Question 33

T/F: hyperthermia can be induced by opioids in cats?

Answer 33

T

Question 34

_____________ release is an important adverse effect to using morphine

Answer 34

Histamine

Question 35

T/F: Butorphanol has stronger antitussive effects than buprenorphine

Answer 35

T

Question 36

T/F: ileus is caused by decreased segmental intestinal motility

Answer 36

F Increased GI segmental motility Decreased GI propulsive motility

Question 37

What is the drug of choice to completely reverse /antagonized the effects of fentanyl

Answer 37

Naloxone