Understanding amphetamines
Amphetamines are stimulant drugs, which means they speed up the messages travelling between the brain and the body.
Some types of amphetamines are legally prescribed by doctors to treat conditions such as attention deficit hyperactivity disorder (ADHD) and narcolepsy (where a person has an uncontrollable urge to sleep). Other types, such as speed, are produced and sold illegally.
The appearance of amphetamines varies. They may be a powder, tablets or capsules, and when sold illegally they may be packaged in aluminium foil, plastic bags or small balloons.
Amphetamine powder ranges in colour from white through to brown, sometimes with traces of grey or pink. It has a strong smell and bitter taste. Capsules and tablets vary considerably in colour.
Illegally produced amphetamines can be a mix of drugs, binding agents, caffeine and sugar. New psychoactive substances may also be added.
MDMA
MDMA is an illegal drug that acts as both a stimulant and a psychedelic. It produces an energising effect, distortions in time and perception, and enhanced enjoyment of tactile experiences.
MDMA (3,4-methylenedioxymethamphetamine) is typically taken orally, usually as a tablet or capsule, and its effects last approximately 3 to 6 hours. The average reported dose is one to two tablets, each typically containing between 60 and 120 milligrams of MDMA. It is not uncommon for users to take a second dose as the effects of the first begin to fade.
MDMA affects the brain by altering the activity of the chemical messengers (neurotransmitters) that allow nerve cells to communicate with one another. Research in animals has shown that, in moderate to high doses, MDMA can be toxic to nerve cells that contain serotonin and can cause long-lasting damage to them.
MDMA also raises body temperature. On rare but largely unpredictable occasions, this has led to severe medical consequences, including death. It causes the release of another neurotransmitter, norepinephrine, which is likely the cause of the increase in heart rate and blood pressure that often accompanies MDMA use.
Ecstasy
Ecstasy (‘eckie’, ‘e’ or ‘Xtc’) is the street term for a range of drugs similar in structure to MDMA, a hallucinogenic amphetamine. It has a similar effect to other amphetamines and is usually taken orally as a tablet. Tablets sold as ‘ecstasy’ in Victoria often contain a mixture of other drugs, such as methylone, MDVP or 2C-I.
Synthetic amphetamines
In recent years, a wide range of synthetic products claiming to have effects similar to amphetamines have been available in Australia. The active ingredient can be any of a number of chemicals, such as methylenedioxypyrovalerone (MDPV), but it is difficult to know exactly what they contain. As a result, they can have more unpredictable effects and are potentially more harmful than amphetamines.
How amphetamines work
When we are stressed or under threat, the central nervous system prepares us for physical action by creating particular physiological changes. Amphetamines prompt the brain to start this ‘fight or flight’ response. The changes include:
- the release of adrenaline and other stress hormones
- increased heart rate and blood pressure
- blood flow redirected into the muscles and away from the gut.
In small doses, amphetamines can banish tiredness and make the user feel alert and refreshed. The burst of energy comes at a price, however. A ‘speed crash’ always follows the high and may leave the person feeling nauseous, irritable, depressed and extremely exhausted.
Effects of amphetamines
The effects of amphetamines, and how long they last, depend on the strength of the dose, the blend of chemicals, and the physical make-up and state of mind of the person taking the drug. Some of the immediate effects include:
- a burst of energy, making the user talkative, restless and excited
- accelerated heart rate and breathing
- high blood pressure
- dry mouth and jaw clenching
- sweating
- dilated pupils
- loss of appetite.
Even when the effects of amphetamines have worn off, there may still be amphetamines in your system. As a rough guide, methamphetamines can be detected in the blood for around four to eight hours after use, and in the urine for around two to five days after use.