Posted by Caleb462 on March 13, 2003, at 3:30:15
In reply to Effexor works different at differents doses??, posted by Tepiaca on March 12, 2003, at 18:12:18
> is the mechanism of action of the effexor changes
> at 75 mg to 300 mg ??? any difference in the brain receptors?
Yes, there is quite a bit of difference between a 75 mg dose of effexor and a 300 mg dose. 75 mg will inhibit serotonin reuptake, but have little effect on anything else. 300 mg will strongly inhibit both serotonin and norepinephrine reuptake, and may weakly inhibit dopamine reuptake.Effexor is basically considered an SSRI at doses below 150 mg. At 150 mg or above it is both a serotonin reuptake inhibitor and a norepinephrine reuptake inhibitor. Not sure what dose dopamine reuptake inhibition begins, but it is probably pretty high, and may not even be signifigant enough to have a theraputic effect.
As for brain receptors, as far as I know, effexor has no affinity for any particular receptors, only reuptake pumps. I could be wrong though.
poster:Caleb462
thread:208505
URL: http://www.dr-bob.org/babble/20030310/msgs/208660.html