Posted by SLS on September 28, 2001, at 12:19:15
In reply to Zyprexa and Serotonin ???, posted by Janelle on September 27, 2001, at 21:58:37
> Anyone here (SalArmy4Me, this could be right up your alley! Ditto for JohnL !) know if Zyprexa works even slightly on Serotonin levels (kind of like an SSRI, but not to the same extent) ??? I heard somewhere that it does, but I'd like confirmation or rebuttal of this from the well-informed and knowledgeable people on here! Thanks.
Hi Janelle.My turn.
You ask a very interesting question. I think I'll look into it.
What is known about Zyprexa and some of the other "atypical" antipsychotics (Geodon, Risperdal, Seroquel, and Clozaril) is that it blocks a serotonin (5-HT) receptor known as 5-HT2a. I believe that this results in reducing, rather than increasing, the rate at which these serotonergic neurons fire. Some of the antidepressants do this as well (trazodone, Serzone, and Remeron).
The action that Prozac and the other SSRIs are noted for are their ability to increase the concentration of serotonin in the gap between neuron_1 and neuron_2. It accomplishes this by preventing neuron_1 from removing the serotonin from this gap. Neuron_1 communicates its messagee to neuron_2 by releasing serotonin into the gap. Neuron_2 becomes stimulated to relay this message along to the next neuron when enough of its receptors are occupied by the serotonin released by neuron_1. Under normal circumstances, neuron_1 cleans up after itself by absorbing the serotonin it has released and recycling it to use again. It does this by using little delivery trucks known as transporters. SSRIs (Selective Serotonin Reuptake Inhibitors) inhibit this reuptake of serotonin by preventing the transporters from doing their jobs. So of course, this leads to an accumulation of serotonin in the gap and an increase in the number of receptors along neuron_2 to be occupied and stimulated.
I have not yet encountered any information suggesting that Zyprexa inhibits the reuptake of serotonin. However, some studies have reported that Geodon does.
* serotonin = 5-HT = 5-HydroxyTryptomine = monoamine neurotransmitter
I hope this explanation helped.
- Scott
poster:SLS
thread:79770
URL: http://www.dr-bob.org/babble/20010927/msgs/79817.html