title: Studies on drug metabolism by use of isotopes. XXVIII--Biological isotope effect for deuterated ephedrine.
abstract: The stability of the deuterium label and the occurrence of an isotope effect for deuterated (-)-ephedrine during metabolic processes were investigated. Determination of the deuterium content in deuterated (-)-ephedrine and its metabolites excreted into urine showed that little, if any, deuterium exchange had occurred. In rats, a slight isotope effect was observed for p-hydroxylation (about 15%) and glucuronide formation of p-hydroxyephedrine and/or its enzymatic hydrolysis (about 20%). In human subjects, there was about 15% difference in the excretion of norephedrine between deuterated and non-deuterated species.
mesh_terms: D000818:Animals; D003903:Deuterium; D004355:Drug Stability; D004809:Ephedrine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine; D008297:Male; D013058:Mass Spectrometry; D010665:Phenylpropanolamine / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
chemical_list: D010665:Phenylpropanolamine; D003903:Deuterium; C026055:oxilofrine; D004809:Ephedrine