Posted by jamestheyonger on December 23, 2005, at 14:42:15
In reply to Effexor metabolite submitted for FDA approval, posted by jrbecker on December 23, 2005, at 13:27:14
I think desvenlafaxine is the d isomer of venlafaxine, so it is not a metabolite. It will then be metabolized into the active metabolites.
O-desmethylvenlafaxine (ODV) is the primary metabolite of Effexor, prehaps Ed can tell us if
ODV and desvenlafaxine are the same thing or if
desvenlafaxine is just an isomer of Effexor.Any way you cut it, it is a "least patentable difference".
"Metabolism and Excretion : Following absorption, venlafaxine undergoes extensive presystemic metabolism in the liver, primarily to ODV, but also to N-desmethylvenlafaxine, N,O-didesmethylvenlafaxine, and other minor metabolites. In vitro studies indicate that the formation of ODV is catalyzed by CYP2D6; this has been confirmed in a clinical study showing that patients with low CYP2D6 levels ("poor metabolizers") had increased levels of venlafaxine and reduced levels of ODV compared to people with normal CYP2D6 ("extensive metabolizers"). The differences between the CYP2D6 poor and extensive metabolizers, however, are not expected to be clinically important because the sum of venlafaxine and ODV is similar in the two groups and venlafaxine and ODV are pharmacologically approximately equiactive and equipotent"
poster:jamestheyonger
thread:591573
URL: http://www.dr-bob.org/babble/20051221/msgs/591595.html