Methamphetamine & other amphetamine-type stimulants

www.druginfo.adf.org.au
  • Methamphetamine is a synthetic stimulant drug – a more potent form of the drug amphetamine. Amphetamines belong to a group of drugs called stimulants. Stimulants speed up the messages going between the brain and the body.


  • There are different forms of methamphetamine, generally distinguished by their appearance and perceived purity:
  • Crystalline (ice or crystalmeth) is a highly purified form of methamphetamine with a crystal-like appearance
  • Powder (speed) and Base
  • Some types of amphetamines are legally prescribed by doctors to treat medical conditions. 
AKA (common names)

Base, crystal, ice, glass, crystal meth, shabu, ox blood, whizz, goey, louee

Low - moderate doses
  • Increased energy
  • faster reaction times
  • feeling more awake and alert
  • reduced need for sleep
  • a sense of euphoria and wellbeing
  • increased attention and alertness
  • increased talkativeness
  • feelings of confidence and motivation
  • increased libido
High doses

A high dose of methamphetamines can cause an individual to overdose. 

This means that a person has used more methamphetamine than their body can cope with.  The risk of overdose increase if the strength or purity of the ice is not known.  Injecting ice increases the risk of overdose due to large amounts of the drug entering the blood stream and quickly travelling to the brain.

Apart from intensifying some of the effects already listed, high doses can also result in:

  • blurred vision
  • tremors
  • irregular breathing
  • loss of coordination
  • collapse
  • rapid pounding heart
  • violent or aggressive behaviour
  • hallucinations
  • methamphetamine psychosis
Signs of overdose

Overdose of methamphetamine can happen to anyone. Even small amounts may cause an overdose with some people who have an especially strong reaction to it.

When a person overdoses, it may cause:

  • methamphetamine psychosis
  • faster, irregular or weak heartbeat
  • heart attack
  • bleeding blood vessels in the brain
  • very high fever
  • death (rarely).

Methamphetamine most often causes a general feeling of wellness (euphoria) that is usually called "a rush." Other symptoms increased heart rate, increased blood pressure, and large wide pupils.

If you take a large amount of the drug, you will likely have some more dangerous side effects, including:

  • agitation
  • chest pain
  • heart attack
  • heart stops (in extreme cases)
  • coma (in extreme cases)
  • difficulty breathing
  • kidney damage and possibly kidney failure
  • paranoia
  • seizures
  • severe stomach pain
  • stroke

 

Route of administration & onset
  • Methamphetamine can be swallowed, snorted, smoked or injected.
  • Ice is usually smoked or injected.
  • Depending on how methamphetamines are taken, the effects may be felt immediately (through injecting or smoking) or within 30 minutes (snorting) and approximately 20-30 minutes if swallowed.
Duration of effect & 'come down' (half-life)
  • Following oral administration, peak methamphetamine concentrations are seen in 2.6-3.6 hours and the mean elimination half-life is 10.1 hours (range 6.4-15 hours).
  • The amphetamine metabolite peaks at 12 hours.
  • Following intravenous injection, the mean elimination half-life is slightly longer (12.2 hours).
  • Overall effects typically last 4-8 hours; residual effects can last up to 12 hours.

As the effects of methamphetamine use begin to wear off, an individual may experience a range of effects.

These can last for several days and can include:

  • feeling restless
  • irritable and anxious
  • paranoia
  • depression
  • radical mood swings
  • lethargy; exhaustion; increased sleep
  • uncontrolled violence
Mechanism of action (on the brain)

In the brain, a primary action of methamphetamine is to elevate the levels of extracellular monoamine neurotransmitters (dopamine, serotonin, norepinephrine) by promoting their release from the nerve endings.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2413312/

Tolerance (dependence) & withdrawal
  • People who use methamphetamines on a regular basis may become dependent on them
  • They may also develop a tolerance to methamphetamines, which means they will need to use larger amounts to get the same effect.
  • People who become dependent on methamphetamine typically inject or smoke the drug and use it at least twice per week.
  • Dependence on methamphetamines can be psychological, physical or both. People who are dependent crave methamphetamine and find it very difficult to stop using it.
  • People who are psychologically dependent on methamphetamine may feel an urge to use it when they are in specific situations. 
  • Physical dependence occurs when a person’s body adapts to methamphetamine and gets used to functioning with it present.

If a dependent individual ceases using methamphetamines, they may experience withdrawal symptoms as they get used to functioning without the drug. 

Withdrawal symptoms may include:

  • strong cravings for methamphetamine
  • confusion and poor concentration
  • decreased energy, apathy and the limited ability to experience pleasure
  • Irritability; depression; anxiety; panic; paranoia
  • extreme fatigue and exhaustion
  • headaches
  • general aches and pains
  • hunger and increased appetite
  • disturbed and restless sleep often interrupted by nightmares

The duration and severity of withdrawal remains unclear however, evidence suggest a 1-3 week period for resolution of symptoms.  Although the “crash” has been associated with withdrawal, not all dependent users experience this and it is not considered a clinically significant part of the withdrawal syndrome (Turning Point, 2007)

Short-term harms & risks
  • increased heart rate, breathing and body temperature
  • decreased appetite
  • jaw clenching; teeth grinding
  • nausea and vomiting;
  • dry mouth
  • changes in libido
  • nervousness, anxiety, agitation, panic, paranoia
  • hallucinations
  • repetition of simple acts
  • irritability, hostility, aggression
  • feelings of increased strength
  • itching, picking and scratching
  • headaches; dizziness
  • difficulty sleeping
  • abrupt shifts in thinking and speech
  • dilated pupils (enlarged)
  • irregular heart beat; palpitations
  • shortness of breath (smoking0
  • reduced appetite; stomach cramps; stomach irritation (swallowed)
  • Methamphetamine also activates the cardiovascular system (increased heart rate and blood pressure) and, for this reason, can cause death at high doses

Long-term harms & risks
  • malnutrition and rapid weight loss due to reduced appetite
  • chronic sleeping problems
  • reduced immunity and increased susceptibility to infections due to not sleeping or eating properly
  • cracked teeth and other dental issues from jaw clenching, teeth grinding, dry mouth and poor hygiene
  • high blood pressure and rapid and irregular heartbeat, placing stress on the heart and increasing the risk of heart-related complications such as heart attack and heart failure
  • increased strain on the kidneys which may result in kidney failure
  • increased risk of stroke
  • depression, anxiety, tension, paranoia
  • There is some evidence that methamphetamine can damage brain cells resulting in reduced memory function and impairments in thinking
  • repeated snorting can damage the nasal lining
  • smoking methamphetamine can damage the lungs
  • vein damage from frequent injecting and the injection of impurities and additives

High doses and frequent heavy use of methamphetamine can also cause “methamphetamine psychosis”. 

This is characterised by:

  • paranoid delusions
  • hallucinations and bizarre, aggressive or violent behaviour. 

These symptoms usually disappear a few days after the person stops using ice.