Everything about Amphetamine totally explained
(hydrochloride), (sulfate)
| ATC_prefix=N06
| ATC_suffix=BA01
| ATC_supplemental=
| PubChem=3007
| DrugBank=APRD00480
| synonyms = (±)-alpha-methylbenzeneethanamine, alpha-methylphenethylamine, beta-phenyl-isopropylamine
| smiles = CC(CC1=CC=CC=C1)N
| C=9 | H=13 | N=1 |
| molecular_weight = 135.2084
| bioavailability= Oral "good"; nasal 75%; rectal 95–99%; intravenous 100%
| solubility = (16C°)
| melting_point = 280
| melting_high = 281
| protein_bound = 15–40%
| metabolism =
Hepatic (
CYP2D6)
| elimination_half-life= 10 hours for d-isomer, 13 hours for l-isomer
| excretion =
Renal; significant portion unaltered
| pregnancy_US = C
| legal_AU = Schedule 8
| legal_CA = Schedule III
| legal_UK = Class B
| legal_NL = List I
| legal_US = Schedule II
| legal_status = Prescription-Only Medicine
| routes_of_administration= Oral,
intravenous,
vaporization,
insufflation,
suppository,
sublingual
}}
Amphetamine is a prescription
CNS stimulant commonly used to treat
attention-deficit disorder (ADD) and
attention-deficit hyperactivity disorder (ADHD) in adults and children. It is also used to treat symptoms of
traumatic brain injury and the daytime drowsiness symptoms of
narcolepsy and
chronic fatigue syndrome. Initially it was more popularly used to
diminish the appetite and to control weight. Brand names of the drugs that contain amphetamine include
Adderall and
Dexedrine. The drug is also used illegally as a recreational
club drug and as a performance enhancer. The name
amphetamine is derived from its chemical name:
alpha-
methyl
phen
ethyl
amine. The name is also used to refer to the class of compounds derived from amphetamine, often referred to as the
substituted amphetamines.
History
Amphetamine was first synthesized in 1887 by
Lazăr Edeleanu in
Berlin, Germany. He named the compound phenylisopropylamine. It was one of a series of compounds related to the plant derivative
ephedrine, which had been isolated from Ma-Huang that same year by
Nagayoshi Nagai. No pharmacological use was found for amphetamine until 1929, when pioneer
psychopharmacologist Gordon Alles resynthesized and tested it on himself, in search of an artificial replacement for ephedrine. From 1933 or 1934
Smith, Kline and French began selling the volatile base form of the drug under the name
Benzedrine Inhaler, useful as a decongestant (and readily useable for non-medical purposes too). During World War II amphetamine was extensively used to combat fatigue and increase alertness in soldiers. After decades of reported abuse, the
FDA banned
Benzedrine inhalers, and limited amphetamines to prescription use in 1965, but non-medical use remained common. Amphetamine became a schedule II drug under the
Controlled Substances Act in 1971.
The related compound
methamphetamine was first synthesized from ephedrine in Japan in 1918 by chemist
Akira Ogata via reduction of ephedrine using
red phosphorus and
iodine. The German military was notorious for their use of methamphetamine in
World War II. It is also rumored that Adolf Hitler was receiving daily shots of a medicine that contained certain essential vitamins and amphetamines. The pharmaceutical
Pervitin was a tablet of methamphetamine which was available in Germany from 1938 and widely used in the
Wehrmacht, but by mid-1941 it became a controlled substance, partly because of the amount of time needed for a soldier to rest and recover after use and partly because of abuse. For the rest of the war military doctors continued to issue the drug, but less frequently and under much more restricted circumstances.
In 1997 and 1998, researchers at
Texas A&M University reported finding amphetamine and methamphetamine in the foliage of two
Acacia species native to
Texas,
A. berlandieri and
A. rigidula. Previously, both of these compounds had been thought to be human inventions.
Indications
Along with
methylphenidate (
Ritalin, Concerta, etc.), amphetamine is one of the standard treatments for
ADHD. Beneficial effects for ADHD can include improved impulse control, improved concentration, decreased sensory overstimulation, decreased irritability and decreased anxiety. These effects can be dramatic in both young children and adults. 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 (
Ritalin,
Concerta, etc.), 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. If used within therapeutic limits, amphetamines 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 others.
Contraindications
Stimulants such as amphetamines elevate cardiac output and blood pressure making them dangerous for use by patients with a history of
heart disease or
hypertension. Also, patients with a history of drug dependence or
anorexia shouldn't be treated with amphetamines due to their addictive and appetite suppressing properties. Amphetamines can cause a life-threatening complication in patients taking
MAOI antidepressants. Amphetamine isn't suitable for patients with a history of glaucoma.
Amphetamines have also been shown to pass through into breast milk. Because of this, mothers taking medications containing amphetamines are advised to avoid breastfeeding during their course of treatment.
Pharmacology
Chemical Properties
Amphetamine is a
chiral compound. The
racemic mixture can be divided into its optical isomers: levo- and
dextro-amphetamine. Amphetamine is the parent compound of its own structural class, comprising a broad range of psychoactive
derivatives, for example,
MDMA (Ecstasy) and the
N-methylated form,
methamphetamine. Amphetamine is a
homologue of
phenethylamine.
At first, the medical drug came as the salt racemic-amphetamine sulfate (racemic-amphetamine contains both isomers in equal amounts). Attention disorders are often treated using
Adderall or a generic equivalent, a formulation of mixed amphetamine and dextroamphetamine salts that contain
1/4 dextroamphetamine saccharate
1/4 dextroamphetamine sulfate
1/4 (racemic dextro/laevo-amphetamine) aspartate monohydrate
1/4 (racemic dextro/laevo-amphetamine) sulfate
Pharmacodynamics
Amphetamine has been shown to both diffuse through the cell membrane and travel via the dopamine transporter (DAT) to increase concentrations of dopamine in the neuronal terminal.
Amphetamine, both as d-amphetamine (dextroamphetamine) and l-amphetamine (or a racemic mixture of the two isomers), is believed to exert its effects by binding to the monoamine transporters and increasing extracellular levels of the biogenic amines dopamine, norepinephrine (noradrenaline) and serotonin. It is hypothesized that d-amphetamine acts primarily on the dopaminergic systems, while l-amphetamine is comparatively norepinephrinergic (noradrenergic). The primary reinforcing and behavioral-stimulant effects of amphetamine, however, are linked to enhanced dopaminergic activity, primarily in the mesolimbic dopamine system.
Amphetamine and other amphetamine-type stimulants principally act to release dopamine into the synaptic cleft. The increased amphetamine concentration releases endogenous stores of dopamine from vesicular monoamine transporters (VMATs), thereby increasing intra-neuronal concentrations of transmitter. This increase in concentration effectively reverses transport of dopamine via the dopamine transporter (DAT) into the synapse. In addition, amphetamine binds reversibly to the DATs and blocks the transporter's ability to clear DA from the synaptic space. Amphetamine also acts in this way with norepinephrine (noradrenaline) and to a lesser extent serotonin.
In addition, amphetamine binds to a group of receptors called TrAce Amine Receptors (TAAR). TAAR are a newly discovered receptor system which seems to be affected by a range of amphetamine-like substances called trace amines.
Effects
Physical effects
Physical effects of amphetamine could include reduced appetite, dilated pupils, flushing, loss of coordination, restlessness, dry mouth, headache, tachycardia, increased breathing rate, increased blood pressure, fever, sweating, diarrhea, constipation, blurred vision, impaired speech, dizziness,uncontrollable movements, insomnia, numbness, palpitations, arrhythmia. In high doses or chronic use convulsions, dry or itchy skin, acne, pallor can occur.
Psychological effects
Psychological effects of amphetamine could include euphoria, a sense of well being, increased alertness, increased concentration, increased talkativeness, increased energy, excitability, feeling of power or superiority, repetitive behaviors, increased aggression, and in rare cases paranoia. Effects are similar, but less potent that cocaine, especially when insufflated or injected.
Withdrawal effects
Withdrawal from use of amphetamines can include the following anxiety, depression, agitation, fatigue, excessive sleeping, increased appetite, psychosis, suicidal thoughts.
Dependence & Addiction
Tolerance is developed rapidly in amphetamine abuse, therefore increasing the amount of the drug that's needed to satisfy the addiction. Repeated amphetamine use can produce "reverse tolerance", or sensitization to some psychological effects. Many users 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. Users will commonly stay up for 2 or 3 days avoiding the withdrawals then dose themselves with benzodiazepines or barbiturates to help them stay calm while they recuperate. Chronic users of amphetamines typically snort or resort to drug injection to experience the full effects of the drug in a faster and more intense way, with the added risks of infection, vein damage, and higher risk of overdose. Because of the abuse of amphetamines in the U.S., most brands were discontinued by the 1990s, including the highly abused brand names Biphetamine (known as "black beauties") and Preludin, known on the street as "slams", whose coating was peeled and then injected. Only a few brands of amphetamines are still produced in the United States: those prescribed for narcolepsy, attention-deficit hyperactivity disorder, treatment-resistant depression, and extreme obesity.
Performance-enhancing use
Amphetamine is used by college and high-school students as a study and test-taking aid. Amphetamine increases energy levels, concentration, and motivation, allowing students to study for an extended period of time. These drugs are often acquired through ADHD prescriptions to students and peers, rather than illicitly produced drugs.
Amphetamines have been, and are still used, by militaries around the world. British troops used 72 million amphetamine tablets in the second world war and the RAF got through so many that "Methedrine won the Battle of Britain" according to one report. American bomber pilots use amphetamines ("go pills") to stay awake during long missions. The Tarnak Farm incident in 2002 is an example of when an American F16-pilot accidentally killed several friendly soldiers on the ground, partly due to the use of amphetamine.
Amphetamine is also used by professional, collegiate and high school athletes for its strong stimulant effect. Energy levels are perceived to be dramatically increased and sustained, believed to allow for more vigorous and longer play, though at least one study has found that this effect isn't measurable. This practice can be extremely dangerous, and athletes have died as a result, for example, British cyclist Tom Simpson.
Amphetamine use has historically been especially common among Major League Baseball (MLB) athletes and is usually known by the slang term "greenies". In 2006, MLB banned the use of amphetamines and the ban is enforced by periodic drug-testing. Consequences if a player tests positive are significant, but MLB has received some criticism because these consequences are dramatically less severe than for steroids, with the first offense bringing only a warning and further testing.
Truck drivers, especially long-haul drivers, take amphetamine to combat symptoms of somnolence and to increase their concentration on driving.
Legal issues
In the United Kingdom, amphetamines are regarded as Class B drugs. The maximum penalty for unauthorised possession is five years in prison and an unlimited fine. The maximum penalty for illegal supply is fourteen years in prison and an unlimited fine. Methamphetamine has recently been reclassified to Class A, penalties for possession of which are more severe (7 years in prison and an unlimited fine).
In the Netherlands, amphetamine and methamphetamine are List I drugs of the Opium Law, but the dextro isomer of amphetamine is indicated for ADD/ADHD and narcolepsy and available for prescription as 5 and generic tablets, and 5 and gelcapsules.
In the United States, amphetamine and methamphetamine are Schedule II drugs, classified as CNS (Central Nervous System) Stimulants. 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.
]]
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