Brainscape's Knowledge GenomeTM

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


See full index

Fundamental Neuroscience > Opioids > Flashcards

Opioids Flashcards

1
Q

What are opioids?

(2 marks)

A
  • Narcotic angalesics - reduce pain without producing unconciousness at correct dosage
  • Can induce euphoria - BEST painkiller known
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does opium contain?

(4 marks)

A

Morphine - strongest active ingredient

Codeine

Heroin

Haloxone

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

What are naloxone and nalorphine?

(2 marks)

A
  • Pure antagonists that are structurally similar to heroin but have no efficacy
  • Prevent/ reverse effects of opioids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are methadone and fentanyl?

(3 marks)

A
  • Synthetic drugs
  • Methadone: used for replacement therapy
  • Fentanyl: important synthetic analogue of morphine used in pain therapy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How can morphine be taken?

(2 marks)

A
  • Morphine normally injected intra-muscullary or can be given orally (medicinal)
  • Can use IV for recreational use
  • Small amount of moprhine passes blood brain barrier
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can newborns from opioid addict mothers experience withdrawal symptoms?

(

A
  • Opioid is lipophilic and can pass through placenta
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can opioids be used to treat diarrohea or certain tropical/ parasitic diseases?

A

It affects the GI tract and can cause constipation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some of the reinfrocing and adversive effects?

(2 marks)

A
  • Reinforcer:‘rush’ encourages people to do it again
  • Adverse effects: dysphoria, restlessness and anxiety
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can be seen at higher doses of morphine and overdose?

(2 marks)

A
  • Sedative may lead to unconciousness
  • Acts on brainstems respiratory center - respiratory failure is ultimate cause of death in overdose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does opioid enhance the brains reward system?

(2 marks)

A
  • Lowers electrical current threshold for self-stimulation
  • In this way animals are able to learn to maintain stable blood levels by self administration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does the dopaminergic mesolimbic pathway contribute to opioid reinforcement?

(5 marks)

A
  • Opioids injected inot VTA of midbrain this increases dopaminergic cell firing
  • Thus increasing release of dopamine inot nucleus accumbens
  • β- endorphins and opioids, increase VTA cell firing by inhibiting inhibitory GABA cells
  • Causes increased firing and greater release of DA in NAcc
  • Dynorphin acts on κ-receptors on DA neuron terminals and can reduce release of DA by similar mechanism causing dysphoria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How can chronic use of opioids lead to cross tolerance?

A
  • Cross tolerance among opioids - as many different types substitute for each other and can be used for therapy best way to avoid this is to use less harmful opioid e.g. codeine
  • Can also lead to sensitisation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens if you become dependent on opioids?

(2 marks)

A
  • Depresses CNS function - withdrawal is rebound hyperactivity
  • ‘Neuroadaptive state’ in response to long-term occupation of opioid receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the difference in withdrawals of heroin and methadone?

A

Heroin: very strong but shorter time - high intesity of withdrawal symptoms

Methadone: much milder less intense form but longer lasting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What kind of replacement therapy is used in opioid treatment?

A
  • Use milder opioid when abstinence signs end to prevent dangerous side effects
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which areas of the brain are involved in opioid withdrawal?

(3 marks)

It’s NEVER what you first initially think

A
  • Locus coerulus (LC) and periacqueductal gray (PAG)
    • Sensitive to opioid antagonist in withdrawal
    • NAcc has been found to be important in reinforcement - may have aversive/ motivational effects
17
Q

How can antagonist MK-801 help with prevention of opioid tolerance?

(5 marks)

A
  • Glutamate and its NMDA receptor are involved in opioid tolerance and dependence.
  • Tolerance to morphine was reduced in animal studies by the non-competitive NMDA antagonist dizocilpine (MK-801).
  • MK-801 prevented acquisition of tolerance and dependence but did not reverse them once they had developed.
  • Prevented the neural plasticity and learning component of tolerance and dependence.
18
Q

What does MK-801 do to PKC that prevents chronic opioid use?

(2 marks)

A
  • Prevents increase in PKC in dorsal horn of spinal cord
  • PKC phosphroylates ion channel normally opened by glutamate, enahncing channel function - which may be responsible for tolerance
19
Q

What is the most common form of treatment for opioid addiction?

(3 marks)

A

Methadone maintenance programme

  • Cross-dependece with heroin
  • Cross tolerance that develops to repeated methadone use means normal euphoric effects of heroin are reduced
20
Q

What is buprenorphine?

A
  • Partial agonist for opioid weaker than methadone but can be used for longer
  • Can be abused if crushed and snorted
21
Q

What is the most successful drug for treating nervous system disorders from opioids?

(3 marks)

A
  • Naltrexone (Trexan)
  • Longer duration of action than naloxone
  • Effective when taken orally with few side effects
22
Q

What is the opioid anatagonist that is similar to naltrexone?

(4 marks)

A
  • Nalmefene (Revex) - newer opioid antagonist
  • More potent and longer lasting
  • Blocks opioid receptors HOWEVER craving of drug is not eliminated
  • Less motivated people CAN return to drug use
23
Q

What is the best form of treatment for opioid addiction?

(2 marks)

A
  • Multidimensional approach
  • Induce detoxification, pharmalogical support and group/ individual counselling
24
Q

What are the different opioid receptors and what characteristics do they all share?

(4 marks)

A
  • m, δ, κ and NOP-R = 4 receptors
  • Expression varies dependent on where they are in brain
  • Large group of endogenous ligands share same 4 receptors
  • ALL metabotropic and all couple to Gi to inhbiit cAMP synthesis
25
Q

What are opioid peptides?

(3 marks)

A
  • Endogenous opioid peptides are released naturally in the body for opioid receptors
  • Have 5 AA coding regions and combination of them in the brain give specifiicity of reaction with opioids

Fundamental Neuroscience (19 decks)

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