![[dr. bob]](/dr-bob-sm.gif)
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 3 of 3. This is the beginning of the thread.
Posted by PhoenixGirl on January 24, 2001, at 14:07:07
Does "agonist" mean that a drug increases the effect a particular chemical, and "antagonist" decreases it? Like, what does a dopamine agonist do exactly? I became confused when reading about Amisulpride. I read that it is a dopamine antagonist, but I thought it was an agonist. It's used for schizophrenia, which means it must decrease the effect of dopamine, right? But then I've heard that it increases the effect of dopamine and helps depression. I don't know how it could help depression if it decreased the effect of dopamine.
Is it a dopamine agonist at low doses, and an antagonist at high doses? I'm really confused.
The reason I'm asking mainly is that I'm looking for a drug that increases the effect of dopamine in order to help my depression and sexual side effects of desipramine.
Posted by PhoenixGirl on January 24, 2001, at 14:23:15
In reply to Confused about dopamine agonists v antagonists, posted by PhoenixGirl on January 24, 2001, at 14:07:07
I'm confused about this word too. For example, does a dopamine inhibitor inhibit dopamine reuptake, and thus increase it's effects? Or does it inhibit dopamine's effects?
> Does "agonist" mean that a drug increases the effect a particular chemical, and "antagonist" decreases it? Like, what does a dopamine agonist do exactly? I became confused when reading about Amisulpride. I read that it is a dopamine antagonist, but I thought it was an agonist. It's used for schizophrenia, which means it must decrease the effect of dopamine, right? But then I've heard that it increases the effect of dopamine and helps depression. I don't know how it could help depression if it decreased the effect of dopamine.
> Is it a dopamine agonist at low doses, and an antagonist at high doses? I'm really confused.
> The reason I'm asking mainly is that I'm looking for a drug that increases the effect of dopamine in order to help my depression and sexual side effects of desipramine.
Posted by MarkinBoston on January 24, 2001, at 15:16:53
In reply to Also what does inhibitor mean precisely? » PhoenixGirl, posted by PhoenixGirl on January 24, 2001, at 14:23:15
"Inhibitor" in your context implies less dopamine is released into the synapse (space) between neurons. From there, it either binds to a receptor on the other neuron, or cleared from the synapse via its own cell's reuptake process.
Agonists increase things, usually the release of something, while antagonists reduce it.
Antidepressants generally increase neurotransmission activity, one way or another, and anti-psychotics generally decrease it.
This is based on the monoamine model of how your brain works, but the model is hardly complete or explains everything. I don't know why a number of drugs not classified as antidepressants seem to have an antidepressant effect on some people. Neither do drug companies. Nearly universal on psyc drug description sheets is a statement to the effect of "we aren't exactly sure how this stuff works."
> I'm confused about this word too. For example, does a dopamine inhibitor inhibit dopamine reuptake, and thus increase it's effects? Or does it inhibit dopamine's effects?
>
>
> > Does "agonist" mean that a drug increases the effect a particular chemical, and "antagonist" decreases it? Like, what does a dopamine agonist do exactly? I became confused when reading about Amisulpride. I read that it is a dopamine antagonist, but I thought it was an agonist. It's used for schizophrenia, which means it must decrease the effect of dopamine, right? But then I've heard that it increases the effect of dopamine and helps depression. I don't know how it could help depression if it decreased the effect of dopamine.
> > Is it a dopamine agonist at low doses, and an antagonist at high doses? I'm really confused.
> > The reason I'm asking mainly is that I'm looking for a drug that increases the effect of dopamine in order to help my depression and sexual side effects of desipramine.
This is the end of the thread.
Psycho-Babble Medication | Extras | FAQ
Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.org
Script revised: February 4, 2008
URL: http://www.dr-bob.org/cgi-bin/pb/mget.pl
Copyright 2006-17 Robert Hsiung.
Owned and operated by Dr. Bob LLC and not the University of Chicago.