Reverett - I saw your post regarding the liver enzyme and rate of processing DXM. I just found this and it sounds encouraging...if I am reading it correctly.

http://phoenix.corporate-ir.net/phoe...190&highlight=

Avanir Pharmaceuticals and Concert Pharmaceuticals Announce License Agreement to Develop and Commercialize Deuterium-modified Dextromethorphan for Disorders of the Nervous System
ALISO VIEJO, Calif. and LEXINGTON, Mass., Feb. 29, 2012

"Concert's DCE Platform (Deuterated Chemical Entity Platform) has produced several deuterium-modified dextromethorphan compounds that we believe may provide therapeutically effective levels of dextromethorphan, potentially without the need for an enzyme inhibitor such as quinidine,"

The incorporation of deuterium into specific molecular positions of dextromethorphan, resulting in d-DM, maintained the pharmacology of dextromethorphan and provided significantly enhanced resistance to CYP2D6 metabolism and improved plasma exposure in preclinical testing. As a result, d-DM has the potential to be effective as a treatment for neurological and psychiatric disorders for which dextromethorphan has shown pharmacological activity.