RT Journal Article SR Electronic T1 Chiral Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine and its Phase I and II Metabolites following Controlled Administration to Humans JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1864 OP 1871 DO 10.1124/dmd.115.066340 VO 43 IS 12 A1 Andrea E. Steuer A1 Corina Schmidhauser A1 Yasmin Schmid A1 Anna Rickli A1 Matthias E. Liechti A1 Thomas Kraemer YR 2015 UL http://dmd.aspetjournals.org/content/43/12/1864.abstract AB Generally, pharmacokinetic studies on 3,4-methylenedioxymethamphetamine (MDMA) in blood have been performed after conjugate cleavage, without taking into account that phase II metabolites represent distinct chemical entities with their own effects and stereoselective pharmacokinetics. The aim of the present study was to stereoselectively investigate the pharmacokinetics of intact glucuronide and sulfate metabolites of MDMA in blood plasma after a controlled single MDMA dose. Plasma samples from 16 healthy participants receiving 125 mg of MDMA orally in a controlled study were analyzed using liquid chromatography–tandem mass spectroscopy after chiral derivatization. Pharmacokinetic parameters of R- and S-stereoisomers were determined. Sulfates of 3,4-dihydroxymethamphetamine (DHMA), and sulfate and glucuronide of 4-hydroxy-3-methoxymethamphetamine (HMMA) were identified, whereas free phase I metabolites were not detected. Stereoselective differences in Cmax and AUC24 were observed with the following preferences: R>S for MDMA and DHMA 4-sulfate; S>R for 3,4-methylenedioxyamphetamine (MDA), DHMA 3-sulfate, and HMMA glucuronide; and no preference in Cmax for HMMA sulfate. R/S ratios were >1 for all analytes after 24 hours, independent of the initial chiral preference. These are the first data on chiral pharmacokinetics of MDMA phase II metabolites in human plasma in vivo after controlled administration. The main human MDMA metabolites were shown to be sulfate and glucuronide conjugates.