Brainscape's Knowledge GenomeTM

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


See full index

MS2 Unit 3 > Pharm: Dopaminergic Agents > Flashcards

Pharm: Dopaminergic Agents Flashcards

1
Q

What are the ways in which dopamine’s action is terminated?

A

1) Destruction by MAO A or B
2) Destruction by COMT
3) Recycled by DAT

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

What does the nigrastriatal pathway do?

A

Controls movement
Hyperfunctioning: dyskinetic movement
Hypofunctioning: dyskinetic movement, parkinsonism

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

Mesolimbic pathway

A

Controls reward and perception
Hyperfunctioning: addiction, hallucinations
Hypofunctioning: amotivation, apathy

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

Mesocortical

A

Controls executive function
Hyperfunctioning: hypervigilance
Hypofunctioning: inattention

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

Tuberoinfundibular

A

Controls pituitary prolactin function
Hyperfunctioning: hypoprolactinemia
Hypofunctioning: hyperprolactinemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Dopamine enhancing drugs

A

Used to treat low DA states like Parkinson’s

Levodopa: the precursor to DA, crosses BBB

  • in CNS converted to DA, promotes better movement by improving nigrostriatal functioning
  • too high of a dose –> dyskinetic movement, hallucinations

Carbidopa: often combined with levodopa, prevents peripheral dopamine activity and lowers fatigue, dizziness, nausea

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

Side effects of levodopa

A

Too much DA –> psychosis, mania, dyskinesia

Average dose –> hypotension/syncope, nausea, anxiety/agitation, fatigue

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

What can we use to treat depression caused by a low dopaminergic state?

A

L-methylfolate or s-adenosyl methionine

Increases 1 carbon cycle and allows DA neurons to make more DA

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

What drug increases DA in the synapse?

A

Norepi-DA reuptake inhibitors like bupropion XL:

  • blocks DAT–> more DA in synapse to increase DA activity in the mesocortical pathway
  • side effects: insomnia, jitteriness/hypervigilance, seizures
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Amphetamines

A

Dextroamphetamine, mixed amphetamine salta, lisdexamfetamine
- block DAT like bupropion, may even reverse it. Increases VMAT2, ejecting more DA from nerve terminals

Methylphenidate products
- block DAT

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Modafinil/Armodafinil

A

Stimulants approved for fatigue due to narcolepsy, apnea, shiftwork, NOT ADHD

  • may increase p450-3A4 enzymes
  • increases histamine activity in TMN, activating alertness in frontal cortex
  • increases orexin
  • requires an operating DAT system and may block this reuptake pump
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Stimulant side effects

A
  • creates more DA and NE not only in cortex but also mesolimbic pathway –> ADDICTION
  • high doses –> psychosis
  • moderate doses –> no appetite, weight loss
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What enzyme is responsible for breaking down dopamine?

A

Monoamine oxidase A and B

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What do MAOIs do?

A

Irreversible inhibit MAO-A/B, generally within the neuron, allowing a build up of DA (also 5HT and norepi) because it can’t be broken down

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

MAOI side effects

A

Hypotension, dizziness, insomnia, weight gain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hypertensive Crisis

A
  • can be caused by adding MAOIs and any drug that raises norepi
  • adding any food source that contains tyramine may cause an immediate release of NE stores, creating a hypertensive crisis –> MI, stroke
  • MAO-A breaks down tyramine (spoiled meat/fish, marmite, pickled herring, banana peel, fava beans, smoked meats, aged cheese, tofu)
17
Q

Serotonin Syndrome

A

MAOIs decrease breakdown of 5HT in CNS
- adding an aggressive serotonin drug may create toxic levels of CNS 5HT –> tremor, muscle spasm, ind/dec vitals, hyperthermia, delirium, coma, death

18
Q

COMTI

A

COMT inhibitors

  • COMT degrades monoamines. Inhibiting it –> increased dopamine, norepi
  • treats Parkinson’s patients (Entacapone, Tolcapone)
19
Q

D2 receptor agonists

A

Increase DA activity in treating Parkinsons or Restless Leg Syndrome

  • Bromocriptine
  • Pramipexole
  • Ropinerole
  • Apomorphine injections
20
Q

D3 receptor agonist

A

Aripiprazole - antipsychotic for schizophrenia, depression

  • partial agonist at D3 and D2
  • if DA is low, binding of the partial agonist –> net increase in DA
21
Q

Amantadine

A

Used to treat Parkinsons and influenza

- releases DA from terminal vesicles, blocks DAT, D2 agonist

22
Q

DA synapse depleters

A 
Reserpine 
- used for hypertension, blocks VMAT so vesicles with monoamines can't be released into synapses
Tetrabenazine
- used for Huntington's chorea
- VMATI
23
Q

High potency FGAs

A
  • High affinity for D2 receptor
  • Very selective
  • Blocking D2 in mesolimbic pathway alleviates psychosis by returning pathway from high DA back to normal
  • blocking D2 in nigrostriatal pathway causes abnormally low DA activity and EPS –> parkinsonism

Haloperidol, Fluphenazine, Thiothixine

24
Q

Extrapyramidal Syndrome (EPS)

A

Occurs when DA activity is forced too low

  • Akathsia: restlessness
  • Dystonia: muscle spasm
  • Parkinsonism: like Parkinsons but reversible
  • Neuroleptic Malignant Syndrome: hyperthermia, muscle rigidity, vital sign instability, rhabdo
25
Q

Anticholinergics for Parkinson’s Disease

A
  • inhibiting cholinergic tone in basal ganglia improves dopaminergic tone in nigrostriatal pathway, lowering Parkinson’s symptoms
  • effective in early Parkinsons but not for Parkinsonian EPS
  • Benztropine, trihexyphenadyl, diphenhydramine
26
Q

Tardive dyskinesia

A

Chronic D2 receptor antagonism may cause this permanent movement disorder

  • Choreic movements: fast, quirky
  • Athetotic movements: slow, writhing
27
Q

Low Potency FGAs

A

Have low affinity for D2 antagonism, requires more mg of drug to provide antipsychotic effects
- antagonist D2 but are “messy” –> manipulate other receptors, causing side effects

Chlorpromazine, Thioridazine

28
Q

FGA low potency side effects

A

D2 antagonism–> EPS
Histamine 1 antagonism –> fatigue, increased appetite
Anticholingergic muscarinic –> dry mouth, blurred vision, constipation
Noradrenergic alpha-1 antagonism –> orthostasis

29
Q

SGA mechanism

A

D2 receptor antagonist improves psychosis, mania, aggression
5HT2A antagonist lessens EPS risk
- allows greater blocking of DA in mesolimbic system while allowing better transmission in all other DA pathways (better selectivity)

30
Q

SGA drugs

A

Dones, Rips and Pines
Dones: Risperidone, Paliperidone, Zipasidone, Iloperidone, Lurasidone

Rips: Aripiprazole (partial agonist at D2, D3)

Pines: Olanzapine, Quetiapine, Asenapine, Clozapine (antagonizes D4, D1 also)

31
Q

SGA side effects

A

Dones: possibly more EPS

Pines: more sedating due to more antihistamine activity, more metabolic syndrome inducing

32
Q

Side effects of 5HT2c antagonism

A

Slow metabolism, desensitize leptin system allowing weight gain, increased cholesterol and blood glucose

33
Q

Side effects of 5HT1a partial agonism, 5HT3, 7 antagonism

A

Promotes serotonin activity –> headaches, GI probs, insomnia, anxiety

34
Q

SGA FDA box warnings

A

Suicide risk ages

35
Q

Clozapine

A

The original ‘atypical’ antipsychotic used for refractory schizophrenia

  • antagonizes D2, 5HT2a
  • also antagonizes D1, D4
  • Risk of agranulocytosis (requires WBC and ANC monitoring)
  • Most metabolic risk of any agent
  • Little to zero EPS/TD

MS2 Unit 3 (21 decks)

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