Posted by Mitch on July 3, 2001, at 0:12:11
In reply to Re: Just how much do the SSRIs inhibit norepinephrine? » SalArmy4me, posted by Cam W. on July 2, 2001, at 19:46:55
Cam W.
The charts I saw adjusted for differing potency with respect to selectivity of the differing SSRI's. Paxil has the highest *potency* for blocking serotonin reuptake. So, it's activity at NE reuptake pumps may appear more active relative to the other SSRi's.
Mitch> Sal - Paroxetine (Paxil™) is the SSRI with the most noradrenergic activity (via reuptake blockade). It inhibits both the reuptake of serotonin and norepinephrine. This is probably why it's side effect profile is slightly different from other SSRIs. So, Paxil doesn't inhibit norepinephrine, but inhibits norepinephrine reuptake; and this reuptake is inhibited by 40% of baseline (which really is not that potent). This 40% blockade would be at a specfic dosage (blood concentration) and at a particular time in therapy (single dosing v. multiple dosing v. steady state). The norepinephrine action of Paxil is probably not all that important clinically (but there have been those who do think it is important), but can add to the secondary side effects or ease some of the serotonergic start-up side effects. - Cam
poster:Mitch
thread:68694
URL: http://www.dr-bob.org/babble/20010701/msgs/68784.html