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Old 18th April 2012, 07:44 AM   #1
meow
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Dopamine Antagonists & Dopamine Reuptake Inhibitors???

http://en.wikipedia.org/wiki/Dopamine_antagonist

Quote:
A dopamine antagonist is a drug which blocks dopamine receptors by receptor antagonism. There are five known types of dopamine receptors in the human body; they are found in the brain, peripheral nervous system, blood vessels, gastrointestinal tract[1] and the kidney.

Used as atypical antipsychotics (coupled with serotonin antagonist effects): clozapine, risperidone, olanzapine, quetiapine, and ziprasidone
http://en.wikipedia.org/wiki/Risperidone

Quote:
Risperidone has been classified as a "qualitatively atypical" antipsychotic agent with a relatively low incidence of extrapyramidal side effects (EPS) (when given at low doses) that has more pronounced serotonin antagonism than dopamine antagonism. Risperidone is unique among most other atypicals in that it has high affinity for the D2 receptor (also known as 'tight binding') whereas most other atypicals have 'loose binding' of the D2 receptor. It has actions at several 5-HT (serotonin) receptor subtypes. These are 5-HT2C, linked to weight gain, 5-HT2A, linked to its antipsychotic action and relief of some of the extrapyramidal side effects experienced with the typical neuroleptics.

5-HT1A serotonin receptors (Ki = 420nM)[24]
5-HT1D serotonin receptors (Ki = 100nM)[25]
5-HT2A serotonin receptors (Ki = 0.16nM)[24]
5-HT2C receptors (Ki = 26nM)[25]
5-HT7 irreversible antagonist[26]
D1 dopaminergic receptors (Ki = 536 nM)[24]
D2 dopaminergic receptors (Ki = 3.13 nM)
α1 adrenergic receptors (Ki = 0.8 nM)
α2 adrenergic receptors (Ki = 7.54 nM)
H1 histamine receptors (Ki = 2.23 nM)
QUESTION: does this drug work mainly due to it's action on serotonin or dopamine? or is it a combination? or hard to tell?


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DOPAMINE REUPTAKE INHIBITORS

http://en.wikipedia.org/wiki/Dopamin...take_inhibitor

Quote:
A dopamine reuptake inhibitor (DRI, DARI) is a type of drug that acts as a reuptake inhibitor for the neurotransmitter dopamine by blocking the action of the dopamine transporter (DAT). This in turn leads to increased extracellular concentrations of dopamine and therefore an increase in dopaminergic neurotransmission.

DRIs may be used in the clinical treatment of (ADHD), ... and fatigue as stimulants, obesity as appetite suppressants, and mood disorders as antidepressants. ...social phobia (SP) ...anxiety disorders as anxiolytics, in parkinsonism as antiparkinsonian agents, in drug addiction as anticraving agents
Quote:
Dopamine-releasing agents (DRAs) such as amphetamine and methamphetamine also function as DRIs secondary to their releasing action. To distinguish between DRIs and DRAs, the latter are not included in the above list

Someone explain this better. sounds like adderall does two things -- it releases dopamine and it acts as a DRI (see question below)


Examples of Dopamine Reuptake Inhibitors-- Ritalin, Wellbutrin, Cocaine (from wiki)


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Question: A person I know is not schizophrenic at all instead they have aggression issues, resentments, minor paranoia, and a general profile that fits a need for a Dopamine Antagonist. They take a Stimulant in the morning due to low energy/low ambition/low motivation, poor concentration.... it also helps her with social phobia.

Since this person started taking a DR-Antagonist their mood has dramatically shifted for the better and resentments have melted away.

But they have also been put on Ritalin despite being told they are NOT ADHD.

Question-- Why would they need their Dopamine blocked by Risperdal and at the same time increased by Adderall or Ritalin?


The MD told this person that it is a paradox, but I think there must be a logical answer.

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Question: Adderall vs Ritalin --- is Adderall a riskier drug to take because it causes dopamine to be released whereas Ritalin does not? Is it true that Ritalin does not cause dopamine to be released rather it just functions as a dopamine reuptake inhibitor?

If a person takes Adderall might they run the risk of running into problems down the road as opposed to taking Ritalin? i.e., dopamine depletion, adrenal exhaustion?
(probably best to be careful of the dosage one consumes and the number of hours of sleep you get)

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Old 18th April 2012, 08:10 AM   #2
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Does frivolous blue and purple bolded text make your point come across more clearly?
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Old 18th April 2012, 10:27 AM   #3
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Originally Posted by meow View Post
... A person I know ...
Hi Meow, if this person is yourself, it might help to state so since it would make you free to provide more pertinent info if needed for those who might assist you and so be of better help to you.
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Old 18th April 2012, 10:31 AM   #4
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I would suggest your friend discuss these concerns with the doctor prescribing the medication.
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Old 19th April 2012, 05:57 AM   #5
meow
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Originally Posted by TubbaBlubba View Post
Does frivolous blue and purple bolded text make your point come across more clearly?
i like to use the pretty colors.


Originally Posted by Daylightstar View Post
Hi Meow, if this person is yourself, it might help to state so since it would make you free to provide more pertinent info if needed for those who might assist you and so be of better help to you.
it's not me; it's my sister.

can anyone offer anything?
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Old 19th April 2012, 08:43 AM   #6
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It would really depends upon the prescribing doctor. Most of the ones I worked with rarely prescribed any of teh ADHD medications and I never knew them to do so with an ATP.
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