Posted by King Vultan on July 8, 2004, at 8:16:52
In reply to P450-CYP2D6, posted by Sad Panda on July 8, 2004, at 4:33:37
> Hi All,
>
> I am switching to Effexor + Nortriptyline & am wondering what my plasma levels of each drug will do since they both use the same enzyme. Should I reduce my Effexor doseage by 50%?
>
> Any & All help appreciated. :)
> Panda.
>
Table 6.10 in this reference gives an indication of the degree to which Effexor will inhibit nortriptyline:http://www.preskorn.com/books/omd_s6.html#p91
I believe nortriptyline, as a secondary amine TCA, has approximately the same degree of 2D6 inhibition itself. I don't believe you will see any gigantic increases in blood plasma level of either drug beyond what might normally be expected. Of course, the blood plasma level of the nortriptyline can be monitored, as it is a tricyclic that has well established therapeutic levels. I believe they are generally considered to be 50-150 ng/ml for this drug.
Todd
poster:King Vultan
thread:363939
URL: http://www.dr-bob.org/babble/20040704/msgs/363969.html