Amphetamines

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. These (latter) uses are illegal in most countries. In the USA amphetamines are one of the most frequently reported illicit drugs in high school seniors.

Patients with acute toxicity from amphetamines may have symptoms of lock jaw, diarrhea, palpitations, arrhytmia, syncope, hyperpyrexia, and hypereflexia progressing to convulsions and coma. Patients with chronic use of amphetamines develop a rapid tolerance to the drug and may have to increase the number of pills to reach a desired affect and eventually develop addiction. Patients who develop addiction show symptoms of restlessness, nervousness, 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 give for agitation and delusions. Hypertension and arrhythmias should be treated.

Amphetamine

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 or other individuals in situations requiring vigilance and alertness. Amphetamine is also used illegally to take advantage of these effects.

The term amphetamine causes a certain amount of confusion because it is often used incorrectly. Loosely, amphetamine can describe other drugs with similar, stimulant effects, namely methamphetamine and methylphenidate. Chemists often use the term "amphetamine class" to describe chemicals that are structurally similar (and often similar in effect as well) to amphetamine--namely, chemicals with an ethyl backbone, terminal phenyl and amine groups, and a methyl group adjacent to the phenyl. A large number of chemicals fall into this category, including the club drug MDMA (Ecstasy) and methamphetamine. It is important to note that such an "amphetamine class" does not technically exist. Phamacodynamically, these drugs all fall under the umbrella of central nervous system stimulants; chemically, they are phenylethylamines. Amphetamine, for example, is methylated phenylethylamine, and methamphetamine is double methylated phenylethylamine.

Amphetamine traditionally comes in the salt-form amphetamine sulphate and is comprised of 50% l- and 50% d-amphetamine (where l- and d- refer to levo and dextro, the two optical orientations the amphetamine structure can have). In the United States, pharmaceutical products containing solely amphetamine (for example, Biphetamine) are no longer manufactured. Today, dextroamphetamine (d-amphetamine) sulphate the the predominant form of the drug used; it consists entirely of d-isomer amphetamine, which is acts in a slightly different way on the brain than does l-amphetamine. 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.

It was first synthesized in 1887 by the German Chemist L. Edeleano, who called it "phenylisopropylamine".

Medicinal use

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 (Ritalin), 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 a timed-release combination of four different amphetamine salts.

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 (Ritalin Concerta), 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 uses amphetamines (Dexedrine) as stimulants for pilots, calling them "go-pills". After a mission, the Air Force issues a "no-go pill' (Ambien) 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, or by students hoping to improve their academic performance. There has also been at least one report of the coercive administration of amphetemines to cannery workers in Thailand, in order to enhance productivity (Seabrook, 1996).

However, the majority of cases of non-medicinal amphetamine use appear to be recreational in nature.

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 (Ritalin) amphetamines also prevent the monoamine transporters for dopamine and norepinephrine from recycling them (called reuptake inhibition) which leads to increased amounts of dopamine and norepinephrine in synaptic clefts.

These combined effects rapidly increases 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, and headaches. Fatigue can often follow the dose's period of effectiveness.

Long-term abuse or overdose effects can include tremor, restlessness, changed sleep patterns, 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. Short-term effects can include alertness, euphoria, increased concentration, rapid talking, increased confidence, increased social responsiveness, nystagmus (eye wiggles), hallucinations, and loss of REM sleep (dreaming) 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.

Legal issues

Example 1: 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.

Example 2: In the United States, amphetamine and methamphetamine are Schedule II controlled drugs, classified as a CNS (Central Nervous System) 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^[1].

Books

Seabrook, Jeremy (1996). In the Cities of the South:scenes from a developing world, London ; New York : Verso. ISBN 1859849865.

See also

• Stimulants
• Phenethylamines
• Dextroamphetamine (Dexedrine and part of Adderall)
• Methylphenidate (Ritalin, Concerta)
• Cathinone
• Methcathinone
• Ephedrine
• Attention Deficit Hyperactivity Disorder
• Psychoactive drug
• Clandestine chemistry
• Uncle Fester (author)

External links

• CID 5826 from PubChem (D-form — dextroamphetamine)
• CID 3007 from PubChem (L-form and D,L-forms)
• CID 32893 from PubChem (L-form — Levamphetamine or L-amphetamine)
• USAF use of amphetamines
• Erowid - Amphetamines
• The Good Drugs Guide - Amphetamines
• Lycaeum - Amphetamines
• Srisurapanont et al, Treatment for amphetamine dependence and abuse
• Drugs.com - Amphetamine
• Asia & Pacific Amphetamine - Type Simulant Information Centre - a very extensive information source mangaged by the United Nations Office on Drugs and Crime.

Notes

1. ^  ANNUAL ESTIMATES OF REQUIREMENTS OF NARCOTIC DRUGS, MANUFACTURE OF SYNTHETIC DRUGS, OPIUM PRODUCTION AND CULTIVATION OF THE.... URL accessed on November 19, 2005.