The amphetamines are synthetic compounds patterned after the chemical structure of naturally occurring epinephrine.Because they are similar chemically, they are similar pharmacologically. (See the accompanying article on adrenergic drugs.)Since 1927 amphetamines have been used (legally and otherwise) for their central nervous system (CNS) stimulatory effects. Here are a few generic names followed by trade and street names: amphetamine sulfate (Benzedrine, bennies, uppers); dextroamphetamine sulfate (Dexedrine, dexies); methamphetamine hydrochloride (Desoxyn, Methedrine, crank, crystal, ice, splash, speed); amphetamine-dextroamphetamine combo (Biphetamine, black beauties); propylhexedrine (Benzedrex inhaler). The name "ice" refers to highly pure, highly abused recrystallied methamphetamine, and is a new physical form of an old drug.
While the amphetamines have much the same pharmacology as the adrenergics, it is their CNS stimulation effect that commands the most attention. Desoxyn, for example, elevates the mood, improves concentration and coordination, and delays the onset of fatigue and the need for sleep. It also diminishes the appetite, and for years has been prescribed in weight loss programs where, too often, it has led to abuse and dependency.
Amphetamines are high abuse potential drugs. And why not! Stimulation of higher centers of the brain can be pleasant and rewarding. Taken intravenously, amphetamines can give a rush or "flash" that is irresistible. A speed freak or "tweaker" will mainline 20-40 mg of methamphetamine at first, and then gradually increase the dose to hundreds of milligrams daily as tolerance to the drug develops and increases. Tweakers are driven by a desire to reexperience the ecstasy of the high, which is described as being different from the high following an oral dose.
While the amphetamine doper can be highly tolerant to the effects of his drug - ingesting as much as 1000 mg a day - the neophyte user is not, and the rapid ingestion of 150 mg could be fatal. Heavy speed users can experience the phenomenon of FORMICATION in which the user hallucinates the presence of insects crawling around just under his skin. Amphetamine addicts probably do not develop the physical dependence seen with heroin or alcohol, and the withdrawal crisis (crashing) is likely to be largely emotional (severe depression, fatigue, increased appetite, high fluid intake).
Amphetamines are metabolized in the body more slowly than cocaine. As many as 2 days may be required to eliminate a single dose of desoxyn.
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