Posted by scott-d-o on January 24, 2004, at 22:43:04
In reply to Re: Stimulants, Anti-psychotics, and Dopamine » scott-d-o, posted by Karen Moore on January 24, 2004, at 20:09:37
> Scott,
> Do you have any knowledge or any good resources on how Seroquel specifically effects dopamine levels/recepters depending on dosage? Is it possible that it is actually dopaminergic at low doses?! That would explain a few things... I'm also wondering if there might be a strange counterproductive interaction btween seroquel and amphetamine (adderall)...
> Thanks,
> kmSeroquel is very similar to the older atypical antipsychotic clozapine, in that both are very weak dopamine antagonists and have activity over a very wide range of receptor types, which is why they are regarded to have a very low risk of inducing tardive dyskinsia. I suppose it is possible that Seroquel is dopaminergic at low doses, but you also have to keep in mind that it has a higher affinity for alpha-adrenergic, muscarinic, and histaminic receptors than it actually does for dopamine receptors.
The interaction between antipsychotics and stimulants is a very complex one. Even looking at it in a purely dopaminergic sense, many times antipsychotics will enhance amphetamine-induced dopamine release in certain regions of the brain (usually in prefrontal cortex), and attenuate it in others (usually in the nucleus accumbens.) This makes me think that antipsychotic augmentation could attenuate the euphoric and locomotor response to stimulants, while perhaps enhancing their ability to increase focus and concentration. However, this is only a guess and as you can see, there is a lot going on here.
Sorry, but the best answer I can give you is that they are most likely to oppose each other at theraputically relevant doses. Most studies I have read attempt to determine what doses of certain antipsychotics abolish the locomotor response to stimulants; I've never seen one focus on how they may complement each other; perhaps it is just too complex to even consider.
scott
poster:scott-d-o
thread:302237
URL: http://www.dr-bob.org/babble/20040122/msgs/305199.html