Posted by sowhysosad on April 10, 2009, at 23:25:26
In reply to Re: Wellbutrin 150 mg low dose? » sowhysosad, posted by garnet71 on April 10, 2009, at 22:46:59
> > However, I'd guess that cymbalta acts only like an SSRI in lower doses, much like Effexor does.
>
> Hi - Do you know of any other XXRIs, besides Effexor, with that sort of behavior?
>In another thread desolationrower recently explained the concept of sigmoid function:
"binding is http://en.wikipedia.org/wiki/Sigmoid_function sigmoidal. this is relevant when the drug binds to two different receptors, like velafaxine. that rapid increase in the middle of the curve means that the first receptor gets almost full before the other one really gets going, which is why you only start to get a little bit of NA effect at a high dose of venlafaxine, especially since the binding is quite different."
So, basically, the first receptor would have to reach "saturation point" before reuptake of the second neurotransmitter kicks in.
That would imply that ANY dual uptake inhbitor would behave in the same way as venlafaxine at low doses, albeit favouring the monoamine for which it has the greatest affinity. Duloxetine, milnacipran, amitriptyline, sibutramine, imipramine and cloripramine would all behave that way.
That ties in with my experience with imipramine, where at a moderate dose it had significant noradrenergic effect but little impact on my serotonin.
poster:sowhysosad
thread:889499
URL: http://www.dr-bob.org/babble/20090408/msgs/889890.html