Posted by kaleidoscope on August 7, 2007, at 13:25:01
In reply to Re: Prestiq (Desvenlafaxine Succinate) » kaleidoscope, posted by Larry Hoover on August 6, 2007, at 15:51:40
Hi Lar
Good to hear from you as always.
As far as I know, venlafaxine itself and desvenlafaxine have similar activity.
According to Wyeth...
'Preclinical studies have shown that venlafaxine and its major metabolite, O-desmethylvenlafaxine (ODV), are potent inhibitors of serotonin and noradrenaline reuptake.'
I assume that Effexor would be an effective AD even in patients who have little 2D6 activity. I could be wrong though!
>A parallel situation may exist in e.g. the codeine/morphine pair. Codeine is O-desmethylated by 2D6 to morphine, making codeine a de facto time release form of morphine, but if and only if you have substantial 2D6 activity. People like me, with little or no 2D6 action, get all of the side effects of codeine but none of the benefits of morphine.
Why all the side effects Lar? Many of the side effects of codeine are presumably caused by the morphine metabolite.
Codeine generally has a rapid onset and a short duration of action (4 hours at most for analgesia - although some side effects may last longer). In this sense, it is quite unlike modified-release morphine. I assume that a high percentage of a dose of codeine is converted to morphine via first-pass metabolism, although this is essentially a guess :)
Hope you are doing well Lar and your pain is better controlled.
Take care
poster:kaleidoscope
thread:773437
URL: http://www.dr-bob.org/babble/20070730/msgs/774586.html