The Scientific Committee of the EMCDDA extended with experts from the Member States and
representatives of the Commission, Europol and EMEA have considered the health and social
risks as well as the possible consequences of prohibition of 4-methylthioamphetamine and in
accordance with Article 4 of the Joint Action submit the following conclusions:

6.1 The scientific evidence submitted to the meeting shows that 4-methylthio-amphetamine (4-
MTA) is a potent psychoactive agent which rapidly releases serotonin and inhibits
monoamine oxidase A activity. It has been associated with five deaths within the EU. Ten
non-fatal cases, nine requiring hospitalisation and resuscitation, have been reported from
the UK and Belgium. The reported adverse events are noteworthy in that they have
occurred within a short period of time and in an apparently small population exposed to the
drug. Respiratory collapse has been reported in some cases. A delayed onset of action
apparently increases the risk of overdose and combination with alcohol, MDMA,
amphetamines or ephedrine also appears to increase the risks. Since the drug inhibits
monoamine oxidase A, a serious interaction with certain foods could occur. Toxicity data
normally used to assess the health effects of a new chemical are not available for 4-MTA.

The expert participants noted that 4-MTA had been identified in 6 Member States and also
in Australia. Reports suggest that 4-MTA is sold and consumed as ‘ecstasy’. Anecdotal
reports suggest that this drug may be less attractive than MDMA to users because of its
unpleasant effects.

Compared to MDMA, and also to MBDB, 4-MTA appears to be associated with a higher risk
of acute effects including adverse reactions and overdosage. The long-term risk of
neurotoxicity of 4-MTA on its own is, like MBDB, possibly lower than for MDMA but as in
the case of MBDB no data is available.

6.2 Arising from 6.1 and because 4-MTA is the sulphur analogue of amphetamines already
subject to control in Member States, the opinion which received strong support at the
meeting was that this compound should be placed under control.

This opinion also recommends that a decision to place 4-MTA under control should not
inhibit the gathering of information about drugs on the market and the dissemination of
accurate information on 4-MTA to users and to relevant professionals. The risk of
overdosing due to the delayed onset of action should be highlighted, as should the risks of
mixing it with alcohol, MDMA, amphetamines, ephedrine products and certain tyramine rich
foods (MAOI effects).

6.3 The major chemical precursors of 4-MTA, namely methylthiobenzaldehyde and
methylthiophenylacetic acid are commercially available. The meeting recommends that the
Drug Precursors Committee set up under Article 10 of Regulation 3677/90 and Directive
92/109/EEC closely examine the situation of those precursor chemicals which have been
found in the manufacture of 4-MTA and which are not yet subject to any measure of
surveillance.

6.4 The meeting recommends that, when a new synthetic drug is notified for risk assessment,
arrangements be made for the provision of reference standard material and associated
analytical data to forensic and toxicology laboratories within the European Union. The
meeting further recommends that 4-MTA be included within the UNDCP proficiency testing
programme. One opinion was, that as part of the Early Warning System specific testing of
‘pills’ available on the market should be possible, in order to inform potential users of the
actual composition of those ‘pills’.

Lisbon, 19 May 1999