Posted by SLS on February 6, 2012, at 6:20:33
In reply to Re: Adding Parnate and prazosin. » SLS, posted by g_g_g_unit on February 6, 2012, at 4:44:29
> > > >I think partial agonism at both receptors is important to produce an antidepressant effect.
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> > > What is the role of D3 receptors in depression?
> >
> > D3 receptors occur in limbic structures such as the nucleus accumbens, a region that mediates reward, pleasure, and drive. Dysfunction here is thought to be responsible for anhedonia.
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>
> Are you aware whether most standard anti-depressants will agonize D3 receptors? Is this something MAOIs are capable of?An MAOI might act to help neurons release more dopamine and thus stimulate more D3 receptors.
Two antiparkinson drugs are full agonists at both D2 and D3 receptors. They are pramipexole (Mirapex) and ropinerole (Requip). They are used for depression, but I question their usefulness. They help with restless legs as well.
There is only one drug that acts as a partial agonist at D2 and D3 receptors. This is aripiprazole (Abilify). Partial agonism, compared to full agonism, probably produces a more balanced stimulation of postsynaptic dopamine neurons. I think full agonists tend to poop-out and are liable to produce sedation or "sleep-attacks". Abilify has proven itself out in the field. In my opinion, the full agonists have not.
My depression is remitting little by little. I have not yet reached the same degree of improvement that I had before attempting to discontinue Abilify. I have lost 3-4 weeks as a setback for the time I did not take Abilify. I need to recover the lost ground. I have tried every one of the AAPs with the exception of clozapine (Clozaril). Abilify is the only one that produces a persistent antidepressant effect. I even tried Latuda before returning to Abilify. It was unsatisfactory. Abilify, with its unique D2/D3 partial agonism, is thus a necessary component to my successful treatment. (It is still early in treatment, and success is far from guaranteed, but I tend to be an optimist). The good news is that a new drug, OPC-34712, is a novel D2/D3 receptor partial agonist under investigation for depression. I hope it comes to market. I think it is currently in Phase II. Perhaps this drug won't raise my triglycerides to the extreme levels that Abilify does.
- ScottSome see things as they are and ask why.
I dream of things that never were and ask why not.- George Bernard Shaw
poster:SLS
thread:1005781
URL: http://www.dr-bob.org/babble/20120202/msgs/1009437.html