Chapter 10 - Opioids

Question 1

What are opiods?

Answer 1

a class of psychoactive substances that acy on opioid receptors in the CNS and other parts of the body; produces euphoria (highly abused)

Question 2

Opioids are called ____ and are used for ____

Answer 2

pain relief (also used to treat diarrhea and as a cough suppressant)

Question 3

Opioid death in Canada

Answer 3

major drugs of abuse and causes of many accidental overdose; today fentanyl is the main concern; ~20 deaths a day;

Question 4

Opioids are derived from ____

Answer 4

papaver somniferum (sap of the poppy is raw opium)

Question 5

Three naturally occurring opiates (from opium)

Answer 5

Morphine, codeine, thebaine

Question 6

Morphine can be further processed into ____

Answer 6

Heroine
(Heroine = morphine + acetic anhydride)

Question 7

Five semisynthetic opioids

Answer 7

Diacetylmorphine (heroine), desomorphine (krokodil), buprenorphind, hydrocodone, oxycodone

Question 8

Two fully synthetic opioids

Answer 8

Fentanyl, methadone
-not derived from naturally occurring opioids

Question 9

History of opium use

Answer 9

Used for 1000s of years; sold in drug stores in 19th century

Question 10

Absorption (pharmacokinetic properties)

Answer 10

Oral administration (codéine, méthadone); IV injection (heroine; most common for illicit use); inhalation (used to be smoked)

Question 11

Distribution (pharmacokinetic properties)

Answer 11

readily cross BB ; differ in speed (ex heroine crosses faster than morphine, produces greater high, more potent, 4-8x more addictive)

Question 12

Metabolism (pharmacokinetic properties)

Answer 12

Occurs in the liver; active metabolites with similar psychoactive properties are common

Question 13

Elimination (pharmacokinetic properties)

Answer 13

Rates vary from drug to drug
- methadone and buprenophine and long elimination rates (not as potent)

Question 14

What is the endogenous opioid system?

Answer 14

Comprised of several NT and receptors; NTs consist of β- endorphin, met-enkephalin, leu-enkephalin, dynorphin A, dynorphin B, and neoendorphin (they are neuropeptides that are cleaved from larger propeptide molecules)

Question 15

What is proopiomelanocortin?

Answer 15

source of β-endorphin

Question 16

what is proenkephalin

Answer 16

the source of met- and leu- enkephalin

Question 17

what is prodynorphine

Answer 17

the source of dynorphin A, dynorphin B, and neoendorphin

Question 18

endogenous opioids bind to what 3 types of opioid receptors?

Answer 18

µ (pronounced “mu”)
Δ (“delta”)
κ (“kappa”)

Question 19

most opioids act on the ____ receptor

Answer 19

µ
-opioids are classified by the effects on the receptor

Question 20

pure opioid receptor agonists are ____ and ____

Answer 20

fentanyl and morphone

Question 21

partial opioid receptor agonists

Answer 21

lower efficacy for activating receptors than full agonists
-buprenorphine

Question 22

pure opioid receptor antagonists

Answer 22

block receptors; used to treat opioid addiction or emergency antidote
-naloxone and naltrexone

Question 23

2 ways opioids increase dopamine release in nucleus accumbens

Answer 23

1. inhibiting GABA neurons in the VTA that synapse on DA neurons (leads to disinhibition of DA neurons therefor incr DA in the mesolimbic projection)
2. inhibiting GABA neurons in the NA that project to the VTA (also leads to disinhibition.. same as prev)

Question 24

2 ways opioids affect the pain system

Answer 24

2 pathways affecting nociception
1. Pain information is carried by Aδ and C fibers through the dorsal horn of the spinal cord and release glutamate and substance P at synapses with spinothalamic neurons.
2. Spinothalamic neurons send nociceptive information to the thalamus which routes the information to somatosensory cortex, the cingulate cortex, and the amygdala

Question 25

opioids weaken neurotransmission within the ____ pain pathways

Answer 25

nociception

Question 26

Neurons in the Periaqueductal Gray (PAG) release endogenous opioids in the medulla, which contains a high density of μ opioid receptors. What does this mean?

Answer 26

Inhibits the activity of spinothalamic neurons passing through the medulla, thus reducing nociceptive information flow to the thalamus

Question 27

other effects of opioids

Answer 27

inhibit respiration; inhibit cardiovascular function; inhibit digestion; chronic administration suppresses immune function

Question 28

rush (stages of opioid effects)

Answer 28

initial rapid onset of euphoria

Question 29

high (stages of opioid effects)

Answer 29

feelings of joy and ease

Question 30

nod (stages of opioid effects)

Answer 30

calm, disinterest, unawareness of surroundings

Question 31

straight (stages of opioid effects)

Answer 31

period of normalcy between craving an opioid and feeling the euphoric or other positive effects of an opioid

Question 32

self-administration procedures in animals indicate that opioid agonists produce potent ____

Answer 32

reinforcing effects

Question 33

medicinal use of opioids

Answer 33

diarrhea, cough suppressant; fentanyl and oxycodone are often prescribed for severe pain management; itchiness side effect

Question 34

opioid overdose

Answer 34

severe depression of respiration; weakness; inability to speak; blush lips and skin; unconsciousness; effects magnified by other depressants

Question 35

withdrawal from opioids usual gives the ____ effect

Answer 35

opposite (ex. used for relaxation, restless in withdrawal. used for constipation, diarrhea in withdrawal)
-withdrawal is not life threatening

Question 36

long term opioid detoxification (treating addiction)

Answer 36

lasts ~180 days; involves drug replacement therapy with agonist (methadone)

Question 37

short term detoxification (treating addiction)

Answer 37

lasts ~30 days and uses drug replacement (methadone); more aggressive form of detox and will have moderate withdrawal symptoms

Question 38

rapid detox + ultra rapid detox (treating addiction)

Answer 38

up to 10 days for rapid; 2 days for ultra rapid; both use opioid receptor antagonists (naltrexone); withdrawal symptoms can be severe and patients are often anesthetized

Question 39

what else may have to be treated alongside opioid addiction

Answer 39

psychological disorders or medical conditions like HIV or HepB