Encyclopedia
Amphetamine , also known as
speed, is a synthetic stimulant used to suppress the appetite, control weight, and treat disorders including narcolepsy and
attention-deficit hyperactivity disorder. It is also used recreationally and for performance enhancement .
Illicit production and use of amphetamines occurs on a widescale basis in several
European nations, typically in the form of amphetamine sulfate synthesized from
phenylpropanolamine. In addition, because of the widespread use of amphetamines as a treatment for narcolepsy and
ADD/ADHD in the
USA,
Great Britain,
Australia,
Canada,
Botswana, and other countries, prescription amphetamines are subject to diversion and are one of the most frequently-abused drugs in high schools and colleges.
Toxicity
Patients with acute toxicity from amphetamines may have symptoms of psychosis, disorientation, temporary symptoms associated with
schizophrenia, aggression, delusions, lock-jaw, diarrhea, palpitations, arrhythmia, syncope, hyperpyrexia, and hyperreflexia progressing to convulsions and coma. Patients with chronic use of amphetamines develop a rapid tolerance to the drug and may have to increase the dose to reach the desired effect and eventually develop addiction. Patients that develop addiction show symptoms of restlessness, anxiety, depression,
insomnia, and suicidal behavior. A urine drug screen can be performed to determine the presence of amphetamines. Patients may need to be hospitalized. Supportive therapy is important. Cooling blankets may be used for hyperthermia. Sedation may be obtained with
lorazepam or
diazepam.
Haloperidol may be given for agitation and delusions. Hypertension and arrhythmias should be treated.
Chemistry
Amphetamine was first synthesized in 1887 by the
Romanian
chemist Lazar Edeleanu at the
University of Berlin, who called it "
phenylisopropylamine". Amphetamine is a chiral compound. The racemic mixture can be divided into its optical antipodes: levo- and
dextro-amphetamine. Amphetamine is the parent compound of its own structural class, comprising a broad range of psychoactive
derivatives, e.g.,
MDMA and the
N-methylated form,
methamphetamine. Amphetamine is a homologue of
phenethylamine.
Traditionally the medical drug came in the racemic salt-form
rac-amphetamine sulfate . In the United States, pharmaceutical products containing solely
rac-amphetamine are no longer manufactured. Today, dextroamphetamine sulphate is the predominant form of the drug used; it consists entirely of the
d-
isomer. Attention disorders are often treated using
Adderall or generic-equivalent formulations of mixed amphetamine salts that contain both
d/l-amphetamine and
d-amphetamine in the sulfate and saccharate forms mixed to a final ratio of 3 parts
d-amphetamine to 1 part
l-amphetamine.
Pharmacology
Dextroamphetamine, the eutomer of amphetamine, exhibits its mode of
central action via release and reuptake inhibition of the monoamine
neurotransmitters
norepinephrine and
dopamine , but not
serotonin . Its activity at the vesicular monoamine transporter VMAT2 is of crucial importance in the release process.
Application range
Amphetamine is a synthetic
drug with strong stimulant effects. In the United States, it is most commonly used for treatment of
attention-deficit disorders and narcolepsy, but is also approved as a weight-loss medication in certain cases of
obesity. Within the armed forces only, it is also frequently prescribed as an anti-fatigue pill for pilots and other individuals in situations requiring vigilance and alertness. Amphetamine is also used illegally to take advantage of these effects. The wanted effects stem predominantly from d-amphetamine, l-amphetamine contributes to the unwanted peripheral side effects primarily nausea after the dose loses effects.
Medicinal use
Indicated for:
Recreational uses:
Other uses:
- Used by the US military to combat fatigue and increase wakefulness
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Contraindications:
CNS StimulantsMAOI use |
Side effects:DizzinessTachycardiaSweatingDecrease in appetite/weight lossEuphoria followed by depressionInsomniaAngerAggressivenessHostility
Cardiovascular:
Ear, nose, and throat:
Eye:
Gastrointestinal:
Musculoskeletal:
Neurological:
Respiratory:
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The experimental medical use of amphetamines began in the 1920s. It was introduced in most of the world in the form of the pharmaceutical
Benzedrine in the late-1920s. The drug was used by the militaries of several nations, especially the air forces, to fight fatigue and increase alertness among servicemen. After decades of reports of abuse, the
FDA banned Benzedrine inhalers, and limited amphetamines to prescription use in 1959, but illegal use became common.
Along with
methylphenidate , amphetamine is one of the standard treatments for
ADHD. Beneficial effects for ADHD can include improved impulse control, improved concentration, decreased sensory overstimulation, and decreased irritability. These effects can be dramatic, particularly in young children. The ADHD medication
Adderall is composed of four different amphetamine
salts, and
Adderall XR is a timed release formulation of these same salt forms.
When used within the recommended doses, side-effects like loss of appetite tend to decrease over time. However, amphetamines last longer in the body than
methylphenidate , and tend to have stronger side-effects on appetite and sleep.
Amphetamines are also a standard treatment for narcolepsy as well as other sleeping disorders. They are generally effective over long periods of time without producing addiction or physical dependence.
Amphetamines are sometimes used to augment anti-depressant therapy in treatment-resistant depression.
Medical use for weight loss is still approved in some countries, but is regarded as obsolete and dangerous in, for example, the United States.
Performance-enhancing use
Amphetamines are usually not used by athletes in sports involving extreme cardiovascular efforts, as
methamphetamine and amphetamine put a great deal of additional stress on the heart.
The
United States Air Force used amphetamines as stimulants for pilots, calling them "go-pills." However, recent developments in designing
ampakines, specifically
modafinil, allow the pilots to stay alert without the paranoia and discomfort associated with dextroamphetamine. After a mission, the Air Force issues a "no-go pill" to help the pilot sleep.
Amphetamines have been popular among some truck drivers, construction workers, and factory workers whose jobs require long or irregular shift work or automatic, repetitive tasks. It is for this reason that they are sometimes labeled a "redneck drug." They are also used by white-collar workers trying to stay alert during long hours of multitasking, and by students hoping to improve their academic performance. There has also been at least one report of the coercive administration of amphetamines to cannery workers in Thailand, in order to enhance productivity .
The drug was also popular in the UK during the 1960s and 70s, playing a large part in Mod culture and later used by punks to continue dancing through the night.
Effects of use
Amphetamines release stores of
norepinephrine and
dopamine from nerve endings by converting the respective molecular transporters into open channels. Amphetamine also releases stores of
serotonin from synaptic vesicles. Like
methylphenidate , amphetamines also prevent the monoamine transporters for
dopamine and
norepinephrine from recycling them , which leads to increased amounts of dopamine and norepinephrine in
synaptic clefts.
These combined effects rapidly increase the concentrations of the respective
neurotransmitters in the
synaptic cleft, which promotes nerve impulse transmission in neurons that have those receptors.
Physiological effects
- Short-term physiological effects include decreased appetite, increased stamina and physical energy, increased sexual drive/response, involuntary bodily movements, increased perspiration, hyperactivity, jitteriness, nausea, itchy, blotchy or greasy skin, increased heart rate, irregular heart rate, increased blood pressure, and headaches. Fatigue can often follow the dose's period of effectiveness. Overdose can be treated with chlorpromazine.
- Long-term abuse or overdose effects can include tremor, restlessness, changed sleep patterns, anxiety and increase in pre-existing anxiety, poor skin condition, hyperreflexia, tachypnea, gastrointestinal narrowing, and weakened immune system. Fatigue and depression can follow the excitement stage. Erectile dysfunction , heart problems, stroke, and liver, kidney and lung damage can result from prolonged use. When snorted, amphetamine can lead to a deterioration of the lining of the nostrils.
Psychological effects
- Short-term psychological effects can include alertness, euphoria, increased concentration, rapid talking, increased confidence, increased social responsiveness, nystagmus , hallucinations, and loss of REM sleep the night after use.
- Long-term psychological effects can include insomnia, mental states resembling schizophrenia, aggressiveness , addiction or dependence with accompanying withdrawal symptoms, irritability, confusion, and panic. Chronic and/or extensively-continuous use can lead to amphetamine psychosis, which causes delusions and paranoia, but this is uncommon when taken as prescribed. Amphetamine is highly-psychologically addictive, and, with chronic use, tolerance develops very quickly. Withdrawal is, although not physiologically threatening, an unpleasant experience . This commonly leads chronic users to re-dose amphetamine frequently, explaining tolerance and increasing the possibility of addiction.
Addiction
Tolerance is developed rapidly in amphetamine use, therefore increasing the amount of the drug that is needed to satisfy the addiction. Many abusers will repeat the amphetamine cycle by taking more of the drug during the withdrawal. This leads to a very dangerous cycle and may involve the use of other drugs to get over the withdrawal process.
Legal issues
- In the United Kingdom, amphetamines are regarded as Class B drugs. The maximum penalty for unauthorised possession is three months' imprisonment and a £2,500 fine.
- In the United States, amphetamine and methamphetamine are Schedule II controlled drugs, classified as a CNS Stimulant. A Schedule II drug is classified as one that: has a high potential for abuse, has a currently-accepted medical use and is used under severe restrictions, and has a high possibility of severe psychological and physiological dependence.
Internationally, amphetamine is a Schedule II drug under the
Convention on Psychotropic Substances.
Popular culture
Books
Related pages
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See also
External links
- Srisurapanont et al,
- - a very extensive information source mangaged by the United Nations Office on Drugs and Crime
- - Alcohol and Drugs History Society
References and Notes
