Posted by avid abulia on July 13, 2003, at 16:05:28
In reply to Re: Inverse antagonism??, posted by Jack Smith on July 10, 2003, at 19:24:16
> > from what i've read rispiridone blocks the receptor from binding to seretonin, i'm wondering if this may explain it's properties with regard to my mainia and if other drugs with this property would do the same.
> >
>
> OK, then it's an antagonist. Nothing inverse about it.
>Yeah, inverse antagonism is an oxymoron, an antagonist binds to the receptor and by definition does not cause an effect whatsoever.
There is inverse agonism, wherein one substance binds to a receptor and causes one effect, but if another substance binds it produces the opposite effect, that is probably what you are thinking of.
From what i have heard, 5-HT2A antagonism is useful for the negative symptoms of psychotic illnesses, amotivation/abulia, asocialism, anhedonia, depression, anxiety, and the like, but it is D2/D3 receptor antagonism that lowers pathologically elevated mood.
Risperidone is not even a particularly high-affinity 5-HT2A antagonist, that is why it is the atypical associated with the most EPS.
If you want a 5-HT2a drug with higher affinity for 5-HT2A vs. dopamine receptors, ziprasidone is the only one commercially available that is very significantly higher (by more than an order of magnitude!)
~AA
poster:avid abulia
thread:240547
URL: http://www.dr-bob.org/babble/20030708/msgs/241504.html