Opioid Analgesics

Question 1

prototype opioid

Answer 1

morphine - all other compared to it for efficacy and potency

Question 2

uses of opioids (5)

Answer 2

analgesia, anti-diarrhea, sedation, euphoria,cough suppression

Question 3

opium

Answer 3

greek word meaning juice. the exudate from poppy seeds containing 20 biologically active components including morphine and codeine

Question 4

opiate

Answer 4

drug extracted from exudate of the poppy

naturally occuring agents

Question 5

opioid

Answer 5

natural of synthetic drug that binds to opioid receptors producing agonist effects

Question 6

narcotic

Answer 6

term used to characterize pharmacological compounds used to treat moderate to sever pain

Question 7

Natural opioids occur as:

Answer 7

endogenous endorphins, enkephalins, and dynorphins (these are naturally occuring in the body)

Question 8

natural opioids occur in the exudate of the opium poppy as ___ and ___

Answer 8

morphine and codeine

Question 9

codeine vs morphine

Answer 9

codeine is 6-7x less potent than morphine

fentanyl is 100x more potent than morphine

Question 10

what are the 3 endogenous opioid receptors?

Answer 10

mu 1 and 2, kappa, delta

Question 11

Mu 1 location and fxn

Answer 11

located outside the spinal cord

responsible for central interpretation of pain

Question 12

Mu 2 location and function

Answer 12

located throughout the CNS in the brain and spinal cord

responsible for spinal analgesia, respiratory depression, constipation, physical dependence, and euphoria

Question 13

pharmacological effects of opioids (5)

Answer 13

analgesia, euphoria, cough suppression, sedation, respiratory depression

Question 14

therapeutic effects of opioids (4)

Answer 14

sedation, analgesia, cough suppression, constipation

Question 15

mechanisms of euphoria

Answer 15

opiates modify the action of dopamine in the brain (brain reward pathway)
opioids inhibit GABA inhibitory interneurons which results in the increased activation of dopamine neurons

Question 16

leading cause of opiate dependence and abuse

Answer 16

euphoria

Question 17

T/F opioids can act on a number of different levels to produce an analgesic effect

Answer 17

true - act on site of injury (periphery), SC, or post-synaptic

Question 18

Mechanisms of Analgesia: ASCENDING pain pathway

Answer 18

1. inhibition of afferent pain transmission - blocks pain sensation from going from periphery to brain
2. Peripheral effects - activating opioid receptors on distal ends of primary afferent neurons decreases their activation
3. Dorsal horn of SC
   - presynaptic blocks release of pain-mediating NT’s (reducing incoming pain signals)
   - postsynaptic decreases pain signals traveling up to SC

Question 19

Mechanisms of Analgesia: DESCENDING pain pathway

Answer 19

opioids block inhibitory GABA interneurons (disinhibition) that leads to enhanced inhibition of nociceptive processing in SC and pain relief
-opioids act in midbrain and brainstem (periaqueductal gray area and medulla)

Question 20

Strong opiate agonists are used for

Answer 20

severe pain relief and interact primarily with mu receptors

Question 21

examples of strong opiate agonists

Answer 21

morphine, fentanyl, methadone, heroin

Question 22

moderate opiate agonists are used for

Answer 22

moderate pain, don’t have as high affinity or efficacy as strong agonists

Question 23

examples of moderate opiate agonists

Answer 23

codeine, oxycodone, hydrocodone

Question 24

pros/cons of mixed opioid agonist-antagonists

Answer 24

Pros = analgesia w/ less risk of side effects and addiction
cons = hallucinations

Question 25

examples of mixed opioid agonist-antagonists

Answer 25

buprenorphine, butorphanol, nalbuphine, pentazocine

Question 26

onset and duration of morphine

Answer 26

onset = 15 - 60 minutes | duration of action = 3 - 6 hours

Question 27

agonist at mu, kappa, and delta receptors (which drug)

Answer 27

morphine

Question 28

Hydromorphone action and effect times

Answer 28

duration of action = 3-4 hours | peak effect after 3-=60 minutes

Question 29

properties and effects of hydromorphone

Answer 29

7-10x more potent analgesic than morphine | used in surgical settings (cancer, bone trauma, burns)

Question 30

Fentanyl

Answer 30

transdermal 80x more analgesic potency compared to morphine 10x greater analgesic potency compared to hydromorphone

Question 31

onset/duration of fentanyl

Answer 31

onset is 12-17 hrs transdermal | duration of action is 72 hrs transdermal

Question 32

Codeine

Answer 32

less potent analgesic compared to morphine | - produces less euphoria, lower abuse potential, no physical dependence, can produce significant sedation!

Question 33

Opioid Antagonists: name of drug used for immediate action

Answer 33

Naloxone: IV administration produces a reversal of CNS and respiratory depression w/in 30 seconds

Question 34

opioid antagonist: drug used long term for rehab

Answer 34

Naltrexone lasts up to 72 hrs

Question 35

Pharmacological Tolerance

Answer 35

loss of drug effectiveness over time - decreased effect from constant dose of drug

Question 36

Physical dependence

Answer 36

onset of withdrawal symptoms occur when drug is abruptly removed

Question 37

Withdrawal is linked to which two things?

Answer 37

physical dependence and addiction

Question 38

withdrawal

Answer 38

occurs within 6-10 hrs after last dose | symptoms of withdrawal are oppsite from the effects of the drug!

Question 39

What is the primary pharmacologic intervention used to treat opioid addiction

Answer 39

Methadone!

Question 40

PT Concerns

Answer 40

respiratory depression constipation sedation withdrawal sx schedule PT when drugs reach peak analgesic effect (withdrawal can cause diffuse muscle aches)