Posted by Mitch on July 4, 2001, at 0:55:46
In reply to Re: Just how much do the SSRIs inhibit norepinephrine? » SalArmy4me, posted by Sunnely on July 3, 2001, at 20:22:53
Sunnely,
Interesting, if you do a little math there it appears that Prozac is the *least* selective for 5-HT reuptake pumps and has the most likelihood of the bunch to boost NE (no surprise-it helped my ADHD the best of the bunch). Celexa is the most selective for 5-HT reuptake inhibition. But as far as *potency* goes I am somewhat surprised-evidently sertraline (Zoloft) is somewhat more potent than paroxetine (Paxil)- I had thought Paxil more potent (for 5-HT reuptake inhibition).
The next interesting batch of data that would be fascinating would be the *linearity* of the relationships of the concentration versus the blockade% of the different neurotransmitter reuptake pumps. Maybe this would explain why SSRI's have such a "flat" dose-response curve?
And possibly this would explain the narrower "therapeutic window" for AD's that inhibit reuptake of DA and NE (such as TCA's)?
> The following is a comparison of concentration (nmol/L) of SSRIs needed to inhibit specific neurotransmitter uptake by half:
>
> 1. Serotonin:
>
> Fluoxetine = 6.8; Fluvoxamine = 3.8; Sertraline = 0.19; Paroxetine = 0.29; Citalopram = 1.8
>
> 2. Dopamine:
>
> Fluoxetine = 5000; Fluvoxamine = 42000; Sertraline = 48; Paroxetine = 81; Citalopram = 40000
>
> 3. Norepinephrine:
>
> Fluoxetine = 370; Fluvoxamine = 620; Sertaline = 160; Paroxetine = 81; Citalopram = 6100
>
>
> > I heard on a Grand Rounds at Univ. of CA, Los Angeles that paroxetine inhibits norepinephrine 40%. Could that be true? I know that Citalopram has no action on norepinephrine, though.
poster:Mitch
thread:68694
URL: http://www.dr-bob.org/babble/20010701/msgs/68909.html