Posted by Elizabeth on June 15, 2001, at 0:07:04
In reply to Re: More about list: question to Sal and Elizabeth, posted by Kaysey on June 14, 2001, at 18:26:20
> As always thanks (to both of you) for the valuable information. I have a question that has been addressed before, but the responses have varied. At what (approximate) dosage does the norepinephrine effect 'kick in' for effexor. I have seen everything from 200mg up to over 300 (and that it might be different for effexor vs. bvXR). Ditto that question for the dopamine effect (have seen everything from 250 mg up to 600!). Perhaps this is also something that varies greatly by individual; but is there a designated baseline for each?
One study compared a group receiving 75 mg to one receiving 375 mg. At the former dose, Effexor appears to have some effects on norepinephrine reuptake but is mainly a serotonin reuptake blocker; at the latter dose, there is a clear-cut norepinephrine effect. One observation has been that the NE effect becomes more relevant at about 1 mg/kg.
Unfortunately, it's hard to measure transporter binding directly in human beings, so most of the information on Effexor's dose-related effects comes from animal research. It's not always the case that animal doses in mg/kg can be translated to human doses.
Dopamine reuptake inhibition occurs to a clinically significant extent only at very high doses that I would expect to be hard to tolerate for most people. It is doubtful that this action contributes much to the efficacy of Effexor.
-elizabeth
poster:Elizabeth
thread:66464
URL: http://www.dr-bob.org/babble/20010612/msgs/66530.html