According to the London
Toxicology Group, there has been a seizure in the UK of about 25,000
tablets containing 4-methylthioamphetamine (4-MTA). It is believed that
these were aimed at the ecstasy market.
In a press release today the National Criminal Intelligence Service said
that pills sold as 'Flatliners' contained 4-MTA.
4-MTA originated from research conducted by Professor Dave Nichols of
Purdue University. There is little experimental data on its effects but
it has been linked to one death in Holland and two in the UK (in at least
one of the cases a number of other drugs had also been consumed). The cause
of death may well have been serotoninergic syndrome as 4-MTA is a potent
5-HT releaser and also a monoamine oxidise inhibitor.
Professor Nichols has said of 4-MTA:
"We had been looking for drugs that cause the release of neuronal
serotonin,with the expectation that they might have therapeutic value similar
to the SSRIs. We had noted that selectivity for the 5-HT uptake carrier
seemed to be increased when amphetamine structures had large, hydrophobic
groups in the 4-position. A methylthio group falls into this category.
Methylthioamphetamine was readily synthesised and when tested was a
very potent releaser of 5-HT. We also then discovered that MTA is a fairly
potent inhibitor of MAO-A, which no doubt contributes to the toxic effect.
I suspect that the toxicity of MTA is similar to the "serotonin syndrome"
observed in humans who have been on MAO inhibitors and are placed on SSRIs
MTA may ultimately prove to be the starting material for a reagent we
are trying to develop to map out the residues that line the channel in
the 5-HT uptake carrier and I am sad to see it being used on the streets.
I can't imagine what pleasure it might produce in users because our tests
with similar compounds in rats showed the substances to have aversive or
The effect of MTA therefore must be similar to that of giving an MAO
inhibitor along with Prozac, a combination that is known to be very toxic
and has also led to deaths. With other amphetamines you apparently get
hypertensive crises from peripheral NE release, and often malignant hyperthermia.
It seems unlikely that serotonin release would do the same things, and
in animal studies MTA had little direct effect on DA or NE."
A user who tried 125mg of MTA (purchased from a Dutch smartshop) described
the effect as:
"not psychedelic, nor really stimulant either, neither fish nor
flesh. I won't bother again and don't recommend it".
Although 4-MTA is not currently a controlled substance in Holland, the
VLOS (a club for bonafide Dutch smartshops) refuse to stock it because it
is a completely unknown substance which has never been tested on humans
- the buyers are the test group. The wholesale company which supplies 4-MTA
has advertised it as being "not neurotoxic" - a completely unfounded
Jeroen Burger, of VLOS, commented that:
"substances with these risks should not be sold in smart shops,
especially not amongst those that are members of the VLOS. We have therefore
warned the distributor to stop producing/selling MTA or they will be banned
from the VLOS, as will the smart shops that will keep selling MTA. We hope
this will make MTA disappear before it gets too popular."
4-MTA produces no colour change in a Marquis reagent test.
More details of the chemical structure of this substance can be found
on the London Toxicology
19 November 1998