|
Results for amphetamine
|
On this page:
|
[A(LPHA) + M(ETHYL) + PH(ENYL) + ET(HYL) + AMINE.]
A stimulating drug that affects the brain and the body in a variety of ways, also known by the trade name Benzedrine. Chemically, amphetamine is a racemic mixture of the L and D isomers of α-methyl-β-phenethylamine. The L isomer has more pronounced effects on the body, while the D isomer (commonly referred to as Dexedrine) has a greater effect on the brain. On the whole, the pharmacological effects of amphetamine are to produce an increase in blood pressure, a relaxation of bronchial smooth muscle, a constriction of the blood vessels supplying the skin and mucous membranes, and a variety of alterations in behavior. The mechanisms by which amphetamine produces its effects are not precisely defined. The effects on the body seem to be mediated predominantly through an increase in the activity of the neurons in the sympathetic nervous system via the transmitter norepinephrine. Amphetamine has the ability to release norepinephrine from nerve terminals. The consequence of release is that amphetamine has a spectrum of activity similar to the normal physiological effects of norepinephrine on the peripheral nervous system. Similarly, the major effects of amphetamine on the brain have been related to its ability to release norepinephrine in the hypothalamus, the reticular activating system, and the cerebral cortex. See also
The ability of amphetamine to contract blood vessels in the mucous membranes and to relax smooth muscles in the lung make it an efficacious nasal decongestant. Its ability to cause hyperventilation has resulted in its use as an analeptic. The arousing and insomnia-producing effects have been exploited to treat narcolepsy, a disease characterized by an inability to stay awake. Furthermore, the ability of amphetamine to cause a loss of appetite has promoted its use in diet programs as an anorexic. The enhanced sense of well-being and mild euphoria that are seen after taking amphetamine have led to its use in certain forms of psychiatric depression. One important use of amphetamine is in the treatment of hyperkinetic children, although the paradox of how a stimulant can reduce hyperkinetic behavior is not understood.
Just as the therapeutic uses of amphetamine are a consequence of its pharmacology, so are its side effects. The typical side effects on the body include dry mouth, heart rhythm alterations (palpitations and arrhythmias), hypertension, stomach cramps, and decreased urinary frequency. The central nervous system side effects include dizziness, dysphoria, headache, tremor, restlessness, insomnia, decreased appetite, increased aggressiveness, anxiety, and paranoid panic states. Extreme overdosage can result in convulsions, cerebral hemorrhaging, coma, and death.
The stimulant and euphorogenic side effects of amphetamine have made this drug subject to widespread abuse. The patterns of this abuse, however, vary greatly. The diversity of people taking amphetamine without proper medical supervision makes it difficult to characterize a typical user. More serious abuse occurs in some individuals who take the drug over long periods. As with other drugs of abuse, tolerance will occur after repeated dosing. Chronic use of large amounts of amphetamine can have severe effects on personality. It has been shown that large doses of amphetamine can induce a behavioral state in humans that is nearly indistinguishable from paranoid schizophrenia, but can be reversed upon cessation of the drug. The question of whether or not physical dependence occurs with amphetamine is unresolved. See also Addictive disorders; Narcotic.
Also known as benzidrine. A chemical at one time used as an appetite suppressant; addictive, and a common drug of abuse (‘speed’), its use is strictly controlled by law.
Chemical formula:
Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.
For more information on amphetamine, visit Britannica.com.
Uses
Prescription amphetamines have been used for short periods of time in weight-control programs to suppress appetite and to treat narcolepsy. They were used as vasoconstrictors in inhalant therapy to shrink nasal mucous membranes in such conditions as nasal allergies and asthma; now such inhalants have been banned because of their toxicity. For unknown reasons, amphetamines have a paradoxically calming effect on some hyperactive children, but the use of these drugs to treat such children has been controversial.
Amphetamine Abuse
Popularly known as bennies, crank, speed, pep pills, wakeups, or uppers, amphetamines are addictive and easily abused: users can become psychologically dependent on the drugs and, developing a tolerance for them, can require increasingly large doses (see drug addiction and drug abuse). When the drugs wear off, a long period of sleep ensues, often followed by hunger and depression, which can lead to further use of amphetamines. Amphetamine addiction has been common among such diverse groups as truck drivers, students, and athletes, who have used the drugs for increased energy, alertness, or endurance. Methamphetamine, made from ephedrine and other chemicals in clandestine laboratories in the the United States or Mexico, experienced a resurgence in use in the United States beginning the mid-1990s. Amphetamines are inhaled, taken orally, or injected; as with other injected drugs, needle sharing increases the risk of contracting the AIDS virus. One form of methamphetamine, “ice,” is smoked. For law enforcement purposes in the United States, most amphetamines are grouped with such drugs as cocaine and morphine because of the similarity in their effects, medical usefulness, and high potential for abuse.
Side Effects
Amphetamines can produce severe systemic effects, including cardiac irregularities and gastric disturbances. Chronic use often results in insomnia, hyperactivity, irritability, and aggressive behavior. Addiction can result in psychosis or death from overexhaustion or cardiac arrest. Amphetamine-induced psychosis often mimics schizophrenia, with paranoia and hallucinations.
A drug that stimulates the central nervous system and is used to treat certain conditions, such as attention deficit disorder, depression, and narcolepsy.
A central nervous system stimulant with marked α and β adrenoreceptor activity. Its use is strictly controlled and there are few applications in veterinary medicine. Called also benzedrine.
 |
|
 |
|
|
Amphetamine
|
|
| Systematic (IUPAC) name | |
| 1-phenylpropan-2-amine | |
| Identifiers | |
| CAS number | 405-41-4 (hydrochloride), 60-13-9 (sulphate) |
| ATC code | N06 |
| PubChem | |
| DrugBank | |
| Chemical data | |
| Formula | C9H13N |
| Mol. mass | 135.2084 |
| Pharmacokinetic data | |
| Bioavailability | Oral 20-25%; nasal 75%; rectal 95-99%; intravenous 100% |
| Metabolism | Hepatic |
| Half life | 10–13 hours |
| Excretion | Renal; significant portion unaltered |
| Therapeutic considerations | |
| Pregnancy cat. |
C(US) |
| Legal status |
Controlled (S8)(AU) Schedule III(CA) Class B(UK) Schedule II(US) |
| Routes | Oral, Intravenous, Vaporized, Insufflated, Suppository, sublingualy |
Amphetamine or Amfetamine(Alpha-Methyl-PHenEThylAMINE), also known as beta-phenyl-isopropylamine and benzedrine, is a prescription stimulant commonly used to treat 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 term "Amphetamine" may also refer to the class of compounds derived from Amphetamine, often referred to as the Substituted Amphetamines.
Amphetamine was first synthesized in 1887 by Lazar Edeleanu at the University of Berlin. 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 1927, when pioneer psychopharmacologist Gordon Alles resynthesized it.[1][2] Alles was part of a group of researchers looking for an ephedrine substitute. In 1937, it became available in tablet form. During World War II it 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 illegal use became common. Amphetamine became a schedule II drug in 1970.
The related compound methamphetamine was first synthesized from ephedrine in Japan in 1919 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 Two. The German pharmaceutical Pervitin is an oral pill of 3mg which was made available in 1938, but by mid-1941 it became a controlled substance, reportedly because of the amount of time needed for a soldier to rest and recover after use. Military doctors were then given guidelines on how they should issue it.[citation needed]
In 1997[3] and 1998,[4] 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.[5]
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 (Ecstasy) and the N-methylated form, methamphetamine. Amphetamine is a homologue of phenethylamine.
At first, the medical drug came in the racemic salt d, l-amphetamine sulfate (racemic amphetamine contains levo- and dextro-form in equal amounts). Today, dextroamphetamine sulfate is the predominant form of the drug used;[citation needed] it consists entirely of the d-isomer. Attention disorders are often treated using Adderall or a generic equivalent, a formulation 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.
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. Amphetamine has been shown to both diffuse through the intracellular membrane and travel via the Dopamine Transporter (DAT) to increase concentrations of amphetamine in the neuronal terminal. 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 (DAT) into the synapse.[6] In addition, amphetamine binds reversibly to the dopamine transporter (DAT) 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.
Research published in the Journal of Pharmacology And Experimental Therapeutics (2007),[7] indicates that 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.
Indicated for:
Recreational uses:
Other uses:
|
Contraindications:
|
| Side effects:
Eye:
|
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, 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 (Ritalin, Concerta, etc.), and tend to have stronger side-effects on appetite and sleep.[citation needed]
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 others.
Amphetamine is commonly used by college and sometimes 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, much longer than one would be capable of doing so on his own. Some students may also take it the day of the test. Most students use it only during final examinations, but some use it on a much more regular basis, which can lead to psychological and physical addiction.
Amphetamine is used by some professional athletes for its strong stimulant effect. Energy levels are dramatically increased and sustained, allowing for more vigorous and longer play. This practice can be extremely dangerous, and some athletes have died as a result. Amphetamine use was common among Major League Baseball (MLB) athletes and were commonly known by the slang term "greenies" due to the pills' color. In 2006, MLB banned the use of amphetamines; and the ban is enforced by periodic drug-testing, with serious consequences if a player tests positive.
Some truck drivers, especially long haul drivers, take amphetamine to combat symptoms of somnolence and to increase their concentration on driving.
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 when taken in relatively high doses. This effect is more pronounced in methamphetamine use. 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 increase the concentrations of the respective neurotransmitters in the synaptic cleft, which promotes nerve impulse transmission in neurons that have those receptors.
Tolerance is developed rapidly in amphetamine abuse, therefore increasing the amount of the drug that is needed to satisfy the addiction.[9] 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. Chronic abusers 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. While continuous dosing with amphetamine causes tolerance, intermittent use can produce "reverse tolerance" or sensitization to some psychological effects.[10][11][12][13][14] As a result, regular use commonly results in a quick decrease of unwanted side-effects, but without an equivalent loss of its stimulant properties. As a note, the sensitization is induced more quickly, and persists far longer than withdrawal-related effects, suggesting a phenomenon more complex than a simple tolerance-induced withdrawal syndrome.
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 Bams, 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.[citation needed]
Proponents of the harm reduction philosophy seek to minimize the harms that arise from the recreational use of amphetamines. Safer means of taking the drug — smoked, nasal, oral, and rectal — are encouraged due to the lower risk of overdose, infection, and contraction of bloodborne viruses associated with drug injection. Smoking drugs reveals their effects roughly as fast as injection, as blood directly picks up the drug at the lungs. Amphetamine, in contrast to methamphetamine, is not smokable.
Where the strength of the drug is unknown, users are encouraged to try a small amount first to gauge the strength, to minimize the risks of overdose. For the same reason, the use of two or more drugs at the one time is discouraged. Users are also discouraged from using amphetamines by themselves, as friends can assist in the event of an overdose or amphetamine psychosis.
Amphetamine users that choose to inject should always use new needles and syringes where possible, and not share these with other users. Governments that support a harm-reduction approach often supply new needles and syringes on a confidential basis, as well as education on proper filtering prior to injection, safer injection techniques, and safe disposal of used injecting gear.
On the international scene, amphetamine is a Schedule II drug under the Convention on Psychotropic Substances.[17]
| Phenethylamines |
|---|
| 2C-B • 2C-C • 2C-D • 2C-E • 2C-I • 2C-N • 2C-T-2 • 2C-T-21 • 2C-T-4 • 2C-T-7 • 2C-T-8 • 3C-E • 4-FMP • Bupropion • Cathine • Cathinone • Clenbuterol • DESOXY • Dextroamphetamine • Methamphetamine • Diethylcathinone • Dimethylcathinone • DOC • DOB • DOI • DOM • bk-MBDB • Dopamine • Br-DFLY • Ephedrine • Epinephrine • Escaline • Fenfluramine • Levalbuterol • Levmetamfetamine • MBDB • MDA • MDMA • MDMC • MDEA • MDPV • Mescaline • Methcathinone • Methylphenidate • Norepinephrine • Phentermine • Salbutamol • Tyramine • Venlafaxine |
| Psychoanaleptics: psychostimulants, agents used for ADHD and nootropics (N06B) | |
|---|---|
| Centrally acting sympathomimetics | Amphetamine - Dexamphetamine - Dextromethamphetamine - Methylphenidate - Pemoline - Fencamfamin - Modafinil - Adrafinil - Fenozolone - Atomoxetine - Fenetylline - Propylhexedrine |
| Xanthine derivatives | Caffeine - Propentofylline |
| Other psychostimulants and nootropics | Racetams (Piracetam, Oxiracetam, Aniracetam, Pramiracetam) - Meclofenoxate - Cyprodenate - Pyritinol - Deanol - Fipexide - Citicoline - Pirisudanol - Linopirdine - Nizofenone - Acetylcarnitine - Idebenone - Prolintane - Pipradrol - Vinpocetine |
