Posted by Dopamine123 on February 21, 2008, at 14:01:14
In reply to Re: Seroquel - is it a serotonin antagonist?, posted by bleauberry on February 18, 2008, at 20:15:04
http://www.neurotransmitter.net/drug_reference.html
"Quetiapine (seroquel) is an antagonist at serotonin 5-HT2A receptors (119). It is also a low potency dopamine D2 receptor inverse agonist (106). Quetiapine is an antagonist at alpha-1A-adrenoceptors (25), alpha-1B-adrenoceptors (25), and alpha-2C-adrenoceptors (40). In addition, the drug is a histamine H1 receptor antagonist (27)."
http://www.preskorn.com/columns/0003.html
"Based on its binding profile, some psychiatrists have used mirtazapine both to augment the antidepressant effects of serotonin uptake inhibitors (i.e., SSRIs and low dose venlafaxine) and to treat their adverse effects. To put this discussion in perspective, a few comments about the effects of SSRIs and venlafaxine may be helpful. These antidepressants are believed to work by increasing serotonin availability to the various serotonin receptors in the brain by slowing the neuronal reuptake of serotonin after its release. Thus, these drugs work as indirect serotonin receptor agonists. While SSRIs are "selective" in terms of directly affecting only the serotonin uptake pump, they are not "selective" in terms of their agonism of serotonin receptors. They increase serotonin availability to all serotonin receptors. Agonism of the 5-HT1A receptor is currently believed to be the mechanism mediating the antidepressant efficacy of these drugs. Conversely, agonism of the 5-HT2A, 5HT2C, and 5-HT3 receptors may principally mediate the adverse effects of these drugs: sleep disturbance, anxiety and weight gain, and nausea/loose stools/vomiting, respectively.7"
Seroquel antagonizes the 5-ht2a receptor which can reduce side effects and increase the antidepressant effect of SSRI's. By antagonizing the 5-ht2a receptor there is more serotonin available to activate the 5-ht1a receptor which is thought to mediate antidepressant efficacy.
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poster:Dopamine123
thread:812957
URL: http://www.dr-bob.org/babble/20080221/msgs/813925.html