Posted by Sad Panda on March 5, 2004, at 3:55:35
In reply to Re: Anyone suffer paradoxical depression with TCAs?, posted by King Vultan on March 4, 2004, at 12:56:23
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> > Clomipramine is a potent NE reuptake inhibitor too. Clomipramine, Imipramine, Amitriptyline, Dothepin & Doxepin are very similar in their NE reuptake blocking ability.
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> > Cheers,
> > Panda.
> >
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> In absolute terms, clomipramine's affinity for the NE reuptake transporter is roughly the same as that of amitriptyline and imipramine, but it is about an order of magnitude less than its affinity for blocking serotonin reuptake. OTOH, imipramine and amitriptyline block serotonin and norepinephrine reuptake at roughly the same order of magnitude.
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> I do not know what Dothepin is, but in vitro, doxepin is slightly weaker in absolute terms in its affinity for the NE reuptake transporter than any of the drugs listed above. In vivo, it is drastically weaker than any of these drugs because doxepin's main pharmacological action is blocking histamine H1 receptors, at which it is one of the most powerful drugs available. Because doxepin's action at blockading NE reuptake lies about three orders of magnitude below its histamine blockade (based on the dissociation constants generated from Richelson's and Seeman's classic studies), doxepin has little or no effect on blocking NE reuptake in the real world, at least at reasonable dosages.
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> Todd
>Hi Todd,
Data I have seen on the web indicates that Doxepin is actually the stongest of the Tertiary TCA's with with regard to NE reuptake blocking, however, they are all weak NE reuptake blockers when compared to their H1 blocking abilities.
Dothepin is sulphated Amitriptyline. (Doxepin is oxygenated Amitriptyline). It was Britans most popular TCA primarily becuase it is a weak A1 blocker & causes very minimal orthostatic hypotension, whoever, it is by far the most toxic of TCA's being about twice as toxic is Amitriptyline which itself is far more toxic than Clomipramine.
Cheers,
Panda.
poster:Sad Panda
thread:319923
URL: http://www.dr-bob.org/babble/20040304/msgs/320513.html