Posted by bleauberry on February 24, 2010, at 19:26:52 [reposted on February 26, 2010, at 8:36:11 | original URL]
In reply to Re: Tricyclic most like SNRIs? » bleauberry, posted by conundrum on February 22, 2010, at 22:23:18
> Taken from the following study:
>
> http://cat.inist.fr/?aModele=afficheN&cpsidt=2585906
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> "Duloxetine (5.0 mg/kg, s.c.) and fluoxetine (10.0 mg/kg, s.c.) increased dialysate levels of DA (65 and 60% vs. basal values, respectively), NAD (400 and 90%, respectively), and 5-HT (130 and 110%, respectively) in the frontal cortex (FCX)."
>
> If I'm interpreting this correctly Duloxetine increases norepinephrine more than serotonin or dopamine in the PFC. Perhaps this isn't true through out the brain but it probably has clinical significance.
>
>
>This can be deceiving. There is comparison to only one other drug. Both happen to be Ely Lilly drugs? See where I'm going? But that's just a small part of it.
There is no comparison to a variety of other drugs. So we can't really put these results into perspective.
The rat brain is in many ways different than the human brain. Well, obviously, no brain on the planet is like a human brain. To automatically assume that what a psychiatric drug does to a rat's brain chemicals will do the exact same thing to a human is, well, probably not accurate.
What happened to those initial peaks of NE the next day, a week later, a month later? We don't know. All we know is what a single dose did. We don't know how the brain adapted to that afterwards with chronic usage. Only with acute usage. Did the NE stay high, or did it restabilize to baseline, or did it go lower? We don't know. Even if we did, what does it mean? Nothing. All that matters is how the patient feels, and that cannot be predicted by how much of any brain chemical there is.
I'd say those doses were pretty darn potent for a little rat. So that's a bit misleading.
Interesting though.
Even though Savella is a serotonin and norepinephrine reuptake inhibitor with approximately equal affinity for both, why is it that after chronic usage NE stays elevated but serotonin doesn't? Things just aint that simple, ya know?
There's a lot we don't know. About the best it says is that there is a probability of getting a NE spike if you take a single dose. I have indeed felt that from cymbalta, and liked it, but it was gone by the 4th day of dosing and instead turned into suicidal feelings. So what happened? We don't know.
I think this study got off to a good start but didn't go far enough for useful results.
poster:bleauberry
thread:937959
URL: http://www.dr-bob.org/babble/neuro/20100223/msgs/937963.html