Amphetamine-type stimulants (ATS)

The term “amphetamine-type stimulants” (ATS) was coined during the WHO Meeting on Amphetamines, MDMA and other Psychostimulants in Geneva, 1996.

Amphetamine-type stimulants (ATS) refer to a group of drugs, mostly synthetic in origin, whose principal members include amphetamine, methamphetamine and MDMA (ecstasy). Use of these substances has a stimulatory effect on the central nervous system and influences the levels and action of the important neurotransmitters: dopamine, norepinephrine and serotonin. The action of these neurotransmitters induces a range of excitatory responses in the central nervous system. The differing degrees to which a substance affects these neurotransmitters contributes to the psychostimulant properties of individual ATS. There are also a number of synthetic stimulants that bear little structural similarity to ATS but have comparable mechanisms of action.

AMPHETAMINE AND METHAMPHETAMINE

Amphetamine and methamphetamine produce predominantly stimulant effects as a result of their influence on the levels of dopamine and norepinephrine, and, to a lesser extent, on serotonin. Both substances are under Schedule II of the Convention on Psychotropic Substances of 1971. Amphetamine and methamphetamine found in illicit markets are predominantly produced in clandestine laboratories. This is primarily related to the ease of synthesis and the availability of a variety of precursors and methods that can be used for their manufacture.

The different methods by which these forms can be administered impacts the onset and duration of action. For instance, insufflation causes quick absorption into the bloodstream through the mucosa and so enables a more rapid onset of effects than oral consumption. In general, only methamphetamine is commonly found in the crystal form.

Mechanism of action and resulting effects

Amphetamine and methamphetamine affect neurotransmitters through a number of mechanisms, namely by inducing the release and preventing the reuptake of dopamine, norepinephrine and, to a lesser extent, serotonin. They also inhibit the metabolism of dopamine and norepinephrine. The combination of these processes produces the stimulant effects, such as increased energy, heart rate and blood pressure

“ECSTASY” GROUP SUBSTANCES

This group comprises synthetic substances such as MDMA (3,4-methylenedioxymethamphetamine), MDA (3,4-methylenedioxyamphetamine) and MDEA (3,4-methylenedioxyethylamphetamine).

Similarly to amphetamine and methamphetamine, these substances have stimulant properties and affect, to varying degrees, the levels of the three neurotransmitters dopamine, norepinephrine and serotonin. However, the more pronounced effect on the serotonin neurotransmitter system leads to some differences in their overall pharmacological effects and is likely to be responsible for the empathogenic/ entactogenic effects of “ecstasy” group substances.

The aforementioned “ecstasy” group substances are produced in clandestine laboratories, have no approved medical use, and are under Schedule I of the Convention on Psychotropic Substances of 1971.

Mechanism of action and resulting effects

In addition to producing stimulant effects similar to those of amphetamine and methamphetamine, “ecstasy” group substances, to varying degrees, have more pronounced effects on inhibition of serotonin reuptake and can also exhibit binding affinity for serotonin receptors, which is likely to be responsible for its empathogenic/ entactogenic effects and potentially related to hallucinogenic effects at higher doses.

Source: Terminology and Information on Drugs (Third edition).