Posted by scott-d-o on February 4, 2004, at 0:48:48
In reply to Re: Doxepin v Mirtazapine » scott-d-o, posted by Sad Panda on February 3, 2004, at 23:55:43
> >where did u get your info that 15mg of mirtazapine occupies 100% of h1 receptors?
>
> http://www.preskorn.com and http://www.psychotropical.com
> Two great websites written by Psychiatrists.damn, I was hoping for a direct link ;-)
> >I do agree that more stimulation would occur as the dose increases with mirtazapine due to alpha-2 antagonism (not a good kind of stimulation at that.)
>
> Norepinephrine Alpha-2 blockade is a good thing, it is believed to give an anti-depressant effect, increase libido & help reverse SSRI induced anorgasmia.
>depends on what you mean by "good thing.".. I think the whole idea here is to make the compounds as *selective* as possible, in that regard it is a bad thing.. yes, alpha2 blockade causes catecholamines to be released but in my opinion there are much better ways to achieve the same result. alpha2 antagonists do not act very centrally at all, they act peripherally causing increased adrenaline levels in the blood. if I wanted an antidepressant that worked on DA/NE I would much rather take a selective reuptake inhibitor, MAO-B inhibitor, a psychostimulant or even an antipsychotic at low dose. take a potent alpha-2 antagonist like yohimbine and see how it makes u feel, it's not very fun and I imagine if alpha-2 antagonism was that great then yohimbine would be prescribed as an antidepressant since it's not a very abusable substance..
calling the sexual effects of alpha-2 antagonism a "good thing" is also way too generalized.. good for someone with anorgasmia, but bad for someone with premature ejaculation.. also alpha-2 antagonists are notorious for causing a ton of anxiety.. in fact, they can easily induce panic attack's in people.. that's a bad thing for anyone. btw, alpha2 antagonism can also cause hypertension, just as you state that alpha1 antagonism can cause hypotension.. are you rating these actions at receptors based on what is a good/bad thing for *you*?
> >doxepin however is an alpha-1 antagonist so I would expect the opposite adrenergic response to an increased dose
>
> Norepinephrine Alpha-1 blockade is a bad thing, all the tricyclics do it. It causes Orthostatic Hypotension. One of the biggest difference between Mirtazapine & it's parent Mianserin is most of the A-1 blockade was removed that causes this bad side-effect.
>never said it was a good or a bad thing.. I was merely stating that it would have the opposite effect on adrenergic receptors than an increased dose of remeron.
scott
poster:scott-d-o
thread:306217
URL: http://www.dr-bob.org/babble/20040131/msgs/309155.html