Amfetamine

Amfetamine, also spelled amphetamine, is a central nervous system stimulant in the phenethylamine class. It exists as enantiomers, dextro- (d-amphetamine) and levo- (l-amphetamine), with the dextro form typically exerting stronger central effects. The drug increases synaptic levels of monoamines—primarily dopamine and norepinephrine, and to a lesser extent serotonin—by promoting their release and by inhibiting reuptake. These actions enhance alertness, attention, and energy, and can also affect mood and appetite.

Medically, amfetamine is used to treat attention-deficit/hyperactivity disorder (ADHD) and narcolepsy; certain formulations are used for obesity as a short-term adjunct. It is taken by mouth, in immediate-release or extended-release forms, with dosing tailored to the individual and monitored for efficacy and adverse effects.

Amfetamine has a long history of medicinal use but also widespread nonmedical use. It is a regulated substance in many countries; in the United States it is classified as a Schedule II controlled substance due to its potential for abuse and dependence. Illicit use, diversion, and adulteration pose health risks including cardiovascular and psychiatric complications.

Common adverse effects include insomnia, reduced appetite, tachycardia, hypertension, anxiety, and irritability. At high doses or with prolonged use, there is risk of stimulant-induced psychosis and cardiovascular events. It can interact with monoamine oxidase inhibitors and other stimulants and should be avoided in people with certain heart or vascular conditions, severe hypertension, glaucoma, or a history of substance use disorder, and during pregnancy. The spelling amfetamine is favored in some languages; in English, amphetamine is the standard term, and it should not be confused with methamphetamine, a more potent stimulant.

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