Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PMCOL 200 > Lecture 16 - Opioids I > Flashcards

Lecture 16 - Opioids I Flashcards

1
Q

What is opium?

A

dried latex obtained from the poppy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are opiates

A

only drug derived from opium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an opioid?

A

any drug that binds to an opioid receptor: included opiates, as well as synthetic opioid agonists (fentanyl, heroin, oxycontin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are narcotics?

A

any drug with sleep inducing properties, but now usually by law enforcement to refer to illegal use of opioids for non-medical purposes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is morphine?

A
  • natural opiate b/c it is found in poppy extracts, also an opioid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is heroin?

A

semisynthetic opiate b/c it is not found in poppy extracts, but is synthesized from morphine, also a opioid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is fentanyl?

A
  • opioid, not an opiate as it is not found on poppy extracts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of receptors are opioid receptors?

A

opioid receptors are inhibitory G-protein coupled receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does activation of opioid receptors cause?

A

activation inhibits adenylate cyclase, inhibits calcium release + activates K+ channels => neuronal inactivation + reduced neurotransmitter release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 4 types of opioid receptors?

A
  • mu, delta, kappa, ORL-1 (orphanin receptor ligand)
  • all are Gi GPCRs, but produce different effects when activated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Why do opioid receptors produce different functions when activated

A
  • due to receptor distribution
  • ligand specificity: drugs are selective for different opioid receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How is ORL-1 distributed?

A
  • widely expressed in the CNS
  • last opioid receptor to be identified based on sequence homology
  • poorly studied, but does not share functional similarities with the other opioid receptors
  • may be involved in fear processing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is mu receptor function (agonist)

A
  • analgesia
  • reward
  • antitussive (cough suppression)
  • respiratory depression
  • constipation
  • morphine, codeine, heroine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is mu receptor function (antagonist)

A
  • aversive
  • prevent rewards
  • block overdose
  • naloxone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is delta receptor function (agonist)

A
  • not rewarding
  • no analgesia (except in chronic pain, migraine)
  • some are seizure - inducing (not commercially available, under investigation)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is kappa receptor function (agonist)

A
  • aversive
  • hallucinogenic
  • anxiogenic
  • salvia
17
Q

What is kappa receptor function (antagonist)

A
  • potential antidepressant/anxiolytic
18
Q

What is the difference between full versus partial opioid agonists?

A
  • full mu opioid agonists include morphine, methadone, fentanyl + heroin
  • buprenorphine is a partial agonist at the mu opioid receptor, mild - moderate analgesic efficacy, but safer therapeutic index
19
Q

What is the difference between high versus low potency in opioids?

A
  • full agonists can have different potencies (fentanyl versus morphine)
  • potency also applies to all aspects of the drug (analgesia, euphoria, respiratory depression)
20
Q

What are mixed agonist-antagonist opioids?

A
  • opioid ligands can have multiple effects on more than one opioid receptor
  • buprenorphine is a partial agonist at the mu opioid receptor + antagonist at the delta/kappa receptors
  • common treatment for pain + opioid addiction
21
Q

What are beta arrestins?

A
  • intracellular proteins important for regulating signal transduction at GPCRs
  • following receptor activation + G-protein cleavage, GPCR is phosphorylated, which signals beta-arrestin to bind
22
Q

What is the absorption of opioids?

A
  • well absorbed when taken orally
  • undergoes extensive first-pass metabolism
  • codeine is a prodrug that is metabolized into morphine by liver enzymes therefore less impacted by first-pass effect than morphine (but more susceptible to pharmacogenomic diversity)
23
Q

What is the distribution of opioids ?

A
  • widely distributed through body tissues, with highest conc in highly perfused tissues such as the brain, lungs, liver, kidney + spleen
  • depends on route of administration
  • cross placental barrier + exert effects on fetus that can result in both respiratory depression + physical dependence in neonates
24
Q

What is the metabolism of opioids?

A
  • morphine is metabolized by phase II glucuronidation into morphine-3-glucuronide and morphine-6-glucuronide
  • most important enzyme is UGT2B7
  • morphine-6-glucuronide is an active metabolite (prolong morphine effects)
  • codeine metabolized into morphine by CYP2D6(codeine is a prodrug)
25
Q

What is the excretion of opioids?

A
  • polar metabolites, including glucuronide conjugates (M3G + M6G) of opioid analgesics, are excreted mainly in the urine
  • in patient with renal impairment the effects of active polar metabolites should be considered before the administration of potent opioids such as morphine due to the risk of sedation and respiratory depression
26
Q

What are the three types of endogenous opioid peptides?

A
  • beta endorphins
  • enkephalins
  • dynorphines
27
Q

What are endogenous opioid peptides

A
  • endogenous opioid peptides are generated from a protein precursor
  • each precursors is subject to post-translational modifications that results in synthesis of multiple active peptides

PMCOL 200 (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions