The content of ecstasy tablets: implications for the study of their long-term effects

FRANÇAIS :
Les analyses des comprimés d'ecstasy saisis dans le nord-ouest de l'Angleterre en 2001 sont décrites et comparées avec les données déjà mises en évidence par le Forensic Science Service sur la Grande-Bretagne, de 1991 à 2001. Résultats : tous les comprimés contenaient du MDMA (entre 20 et 109 mg, 60 à 69 mg en moyenne) ; certains contenaient aussi du MDEA. Les 'Mitsubishi' étaient les comprimés les plus courants. Le taux de MDMA était très constant dans les comprimés dénommés 'White Dove'. Ces analyses semblent confirmer en général la baisse du taux de MDMA dans les comprimés d'ecstasy.
ENGLISH :
Aims. To examine the variation in the content of ecstasy tablets seized in the north-west of England during 2001 and to compare it to the UK average from 1991 to 2001. Measurements. All tablets submitted to the Forensic Science Service in the northwest of England during 2001 were analysed by high performance liquid chromatography with diode array detection (HPLC-DAD). The mean MDMA content of these tablets are reported and compared to results from all Forensic Science Service laboratories in the United Kingdom from 1991 to 2001. Multiple samples (n = 80) from a single large seizure of White Dove tablets were analysed to determine the variation due to manufacturing. Findings. All tablets submitted from the north-west of England to the Forensic Science Service in 2001 were found to contain 3,4- methylenedioxymethamphetamine (MDMA) and some also contained 3,4- methylenedioxyethamphetamine (MDEA). The MDMA content of these tablets ranged from 20 to 109 mg and the mean was in the 60-69 mg range. Mitsubishi tablets were the most common type and they were found across the whole range. The low variation of MDMA content in the White Dove tablets suggests that these tablets were well manufactured. The data from the north-west of England in 2001 are in agreement with tablet analyses over the past 10 years which show that the average MDMA content is falling. Conclusions. The amount of MDMA in ecstasy tablets is axiomatic to the discussion of their long-term effects. In order for the observed differences in ecstasy users to be the result of MDMA-induced neurotoxicity it is necessary for them to have ingested one or more neurotoxic doses. These data indicate that the amount of MDMA in ecstasy tablets is dropping and that dose-effect relationships need to take this into account. (Author' s abstract)