Does polymorphic CYP2D6 mediate O-demethylation of the opioid analgesic tramadol?
High correlation was found between tramadol-O-demethylation and sparteine oxidation in 71 extensive metabolizers of sparteine (rs = 0.544). The mean metabolic ratio of tramadol O-demethylation was significantly higher in poor metabolizers of sparteine than in extensive metabolizers (4.4 vs 0.8). These in vivo results confirm that tramadol O-demethylation is carried out to a large extent by the polymorphic CYP2D6.
Based on the sample numbers tested in this study, polyphenols appear to effectively enhance the oxidation stability without altering the mechanical properties or pin-on-disc wear rate of radiation-crosslinked UHMWPE.