Posted by Larry Hoover on April 19, 2009, at 15:13:46
In reply to Re: Has Pristiq proven to be clinically useful? » Larry Hoover, posted by TriedEveryDrug on April 19, 2009, at 10:31:01
> Larry,
>
> Do you know if Desvenlafaxine inhibits 2d6 at all? I know it is metabolized by 3A4.Yes. It must inhibit it, as it's a substrate for the enzyme. Products of enzymatic reactions are by definition substrates for the reverse reaction. So, there would be some production of venlafaxine from desvenlafaxine. The limiting factors are the low affinity of desvenlafaxine for the 2D6 enzyme, and variable activity of that enzyme.
> in addition to being metabolized by 2d6, venlafaxine itself had an inhibitory effect, for instance desipramine AUC is raised 4.5 fold by 75mg of venlafaxine.
>
> I've been interested in a desipramine/venlafaxine combo, but the decreased metabolism of desipramine had me worried. Maybe pristiq is the ticket.There happens to be a study that looks directly at the simultaneous use of desvenlafaxine and desipramine. Preskorn concludes the effect is low-risk.
Even extensive metabolizers at 2D6 produced very little venlafaxine.
http://www.ncbi.nlm.nih.gov/pubmed/19057238
> Though epocrates claims there is an interaction. Maybe their data are wrong.
>
> ThanksYou're welcome.
Lar
poster:Larry Hoover
thread:891545
URL: http://www.dr-bob.org/babble/20090416/msgs/891622.html