Posted by psychobot5000 on June 6, 2007, at 12:22:05
In reply to Re: Guanfacine XR Significantly Improved ADHD Symp, posted by linkadge on June 6, 2007, at 6:33:11
> I am guessing it was more effective for the hyperactive form than the innatentive form.
>
> A number of animial models of ADHD involve hyperactivity of noradrenaline with respect to dopamine, esp in the frontal cortex.
>
> Perhaps part of the drug effect is to alter this ratio?
>
> LinkadgeHmm. That's interesting. I know that remeron increases noradrenaline, for example (in an action precisely opposite the alpha 2 agonists), and was counterproductive for my own ADHD-type symptoms. Of course that could have been its effects on H1, (or serotonin receptors), but for several reasons, I don't think this was the case. ...I guess I can see how extra NA might exacerbate hyperactivity (though doubtless this is a crude way of putting it).
I think docs have worked along that type of line of thought concerning guanfacine, but as far as I can tell, the studies seem to show real effects on inattention as well, sort of in contrast to conventional wisdom. I've seen some much smaller studies in which it seems to help memory and concentration very modestly (tests against placebo in reorganizing shapes to fit together, or something like that).
This may be in contrast to clonidine, though, which often doesn't get positive results for inattention. This could be explained by the unwanted action of blocking alpha-1 receptors, or also by its lack of selectivity for the alpha-2a subset.
But the DA/NA ratio you mention seems an interesting idea. Very few medications that increase dopamine do so without increasing NA as well, after all, and maybe they'd be more effective if they did. Certainly ought to have less effect on the heart and be less anxiogenic.
Psychbot5000
poster:psychobot5000
thread:761347
URL: http://www.dr-bob.org/babble/20070604/msgs/761484.html