HAIR ANALYSIS FOR DRUG-ABUSE .15. DISPOSITION OF 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA) AND ITS RELATED-COMPOUNDS INTO RAT HAIR AND APPLICATION TO HAIR ANALYSIS FOR MDMA ABUSE

In order to clarify the mechanism of drug incorporation into hair, dis position of 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymet hamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine (MDEA), 3-meth oxy-4,5-methylenedioxyamphetamine (MMDA) and metabolites of MDMA, 4-hy droxy-3-methoxyamphetamine (HMAP) and 4-hydroxy-3-methoxymethamphetami ne (HMMA), into hair was investigated with an animal model. After the intraperitoneal administration of those six drugs to pigmented hairy r ats (5 mg/kg/day, 10 days, n = 3), the parent compounds and their meta bolites in the rat plasma (5, 15, 30, 60, 120, 360 min after administr ation) and in the newly grown rat hair for 4 weeks were determined by GC/MS-SIM. When the ratio of hair concentration to area under the conc entration versus time curves (AUCs) in plasma was represented as an in dex of incorporation rate (ICR) of drugs into hair, the order of ICRs was HMAP < MDA < HMMA < MDMA < MDEA < MMDA. In the comparison between MDA, MDMA and MDEA, their ICRs increased according to the length of ca rbon branches from proton to ethyl at the N position. From the point o f view that the ICRs of MMDA was 2.3 times as much as that of MDA, the methoxy group on the benzene ring seemed to serve as a positive facto r for the ICR. However, the ICRs of 4-hydroxy-3-methoxy compounds, HMA P and HMMA, were lower in comparison with those of MDA and MDMA, respe ctively. On the other hand, the ICRs of MDA, MDMA and MDEA were 5.5-6. 1 times larger than those of amphetamine, methamphetamine and ethylamp hetamine, suggesting that the methylenedioxy group on the benzene ring raises their ICRs very positively. Moreover, in order to apply the re sults from the animal experiments to human cases, the scalp hair sampl es of seven MDMA abusers were analyzed. MDMA and its metabolites, MDA, were simultaneously detected in all the samples by GC/MS. In the two samples, MDEA was found in addition to MDMA and MDA. It was shown that a hair sample is a good specimen for the confirmation of retrospectiv e use of methylenedioxyamphetamines. (C) 1997 Elsevier Science Ireland Ltd.