TY - JOUR T1 - STEREOCHEMICAL ANALYSIS OF 3,4-METHYLENEDIOXYMETHAMPHETAMINE AND ITS MAIN METABOLITES IN HUMAN SAMPLES INCLUDING THE CATECHOL-TYPE METABOLITE (3,4-DIHYDROXYMETHAMPHETAMINE) JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 1001 LP - 1007 VL - 32 IS - 9 AU - Nieves Pizarro AU - Magí Farré AU - Mitona Pujadas AU - Ana Ma͢ Peiró AU - Pere N Roset AU - Jesús Joglar AU - Rafael de la Torre Y1 - 2004/09/01 UR - http://dmd.aspetjournals.org/content/32/9/1001.abstract N2 - 3,4-Methylenedioxymethamphetamine (MDMA; “ecstasy”) is a designer drug commonly misused in large segments of young populations. MDMA is usually formulated in tablets of its racemate (1:1 mixture of its enantiomers) in doses ranging from 50 to 200 mg. MDMA has an enantioselective metabolism, the (S)-enantiomer being metabolized faster than the (R)-enantiomer. Different pharmacologic properties have been attributed to each enantiomer. The carbon responsible for MDMA chirality is preserved along its metabolic disposition. An analytical method has been developed to determine MDMA enantiomers and those from its major metabolites, 3,4-methylenedioxyamphetamine (MDA), 3,4-dihydroxymeth-amphetamine (HHMA), and 4-hydroxy-3-methoxymethamphet-amine (HMMA). It has been applied to the analysis of plasma and urine samples from healthy recreational users of MDMA who participated voluntarily in a clinical trial and received 100 mg (R,S)-MDMA · HCl orally. (R)/(S) ratios both in plasma (0-48 h) and urine (0-72 h) for MDMA and MDA were >1 and <1, respectively. Ratios corresponding to HHMA and HMMA, close to unity, deviate from theoretical expectations and are most likely explained by the ability of MDMA to autoinhibit its own metabolism. The short elimination half-life of (S)-MDMA (4.8 h) is consistent with the subjective effects and psychomotor performance reported in subjects exposed to MDMA, whereas the much longer half-life of the (R)-enantiomer (14.8 h) correlates with mood and cognitive effects experienced on the next days after MDMA use. The American Society for Pharmacology and Experimental Therapeutics ER -