Posted by SLS on April 2, 2002, at 10:53:29
In reply to Re: What Zyprexa is excellent for - Old School, posted by Denise528 on April 2, 2002, at 9:08:02
> Thanks Scott,
>
> Thanks for the explanation, it's clear to me now. However, do SSRIs perform Antagonistic or Agonistic actions or are reuptake inhibitors different?
>
> Denise
In the most generic sense, an agonist promotes, and an antagonist inhibits, the event being referred to.I have seen some authors of medical literature refer to a reuptake-inhibitor as an "indirect" agonist of postsynaptic receptors. These drugs do not attach directly to receptors, and are thus not considered to be receptor ligands. That a serotonin reuptake inhibitor drug like Prozac increases the amount of serotonin in the synaptic cleft (the gap between the pre- and post- synaptic neurons), it causes an increase in the rate of stimulation of the attendant serotonin receptors, as long as these receptors are not also antagonized (blocked) by the same drug. The drug therefore is an agonist of serotonergic receptor stimulation. I do not like this usage of the words "agonist" and "antagonist". They are usually reserved for receptor ligands.
LIGAND: An ion, a molecule, or a molecular group that binds to another chemical entity to form a larger complex. (The American Heritage® Dictionary)
DA (dopamine) antagonists: Zyprexa, Risperdal, Haldol, Thorazine - neuroleptic antipsychotics
DA agonists: Mirapex, Parlodel, Permax, Requip... - anti-parkinsons drugs
-------------------------------------
5-HT = serotoninAmong other things, Serzone does the following:
1. inhibits 5-HT reuptake
2. antagonizes 5-HT2 receptorsThe net effect is that Serzone promotes an increase in the stimulation of 5-HT1 and 5-HT3 receptors, but a decrease in the stimulation of 5-HT2 receptors.
That's enough thinking for today. My brain hurts.
:-)
- Scott
poster:SLS
thread:100817
URL: http://www.dr-bob.org/babble/20020402/msgs/101454.html