Benzphetamine (brand name Didrex) is a substituted amphetamine used short-term along with a doctor-approved, reduced- calorie diet, exercise, and behavioral program for

weight loss Weight loss, in the context of medicine, health, or physical fitness, refers to a reduction of the total body mass, by a mean loss of fluid, body fat ( adipose tissue), or lean mass (namely bone mineral deposits, muscle, tendon, and other co ...

. It is prescribed for

obesity Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's ...

to people who have been unable to lose weight through exercise and dieting alone. It is a prodrug to

dextroamphetamine Dextroamphetamine is a central nervous system (CNS) stimulant and an amphetamine enantiomer that is prescribed for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. It is also used as an athletic performance an ...

and dextromethamphetamine. Benzphetamine is an

anorectic An anorectic or anorexic is a drug which reduces appetite, resulting in lower food consumption, leading to weight loss. By contrast, an appetite stimulant is referred to as orexigenic. The term is (from the Greek ''ἀν-'' (an-) = "without" a ...

, primarily promoting weight loss through reduced appetite. It also slightly increases

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

Pharmacology

Benzphetamine is a sympathomimetic

amine In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen Hydrogen is the chemical element wi ...

and is classified as an

. The drug's main function is to reduce appetite, which in turn reduces caloric intake. Although the mechanism of action of the sympathomimetic appetite suppressants in the treatment of obesity is not fully known, these medications have pharmacological effects similar to those of amphetamines. Amphetamine and related sympathomimetic medications (such as benzphetamine) are thought to stimulate the release of

norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad' ...

and/or dopamine from storage sites in nerve terminals of the lateral hypothalamic feeding center, thereby producing a decrease in appetite. This release is mediated through the binding of benzphetamine to VMAT₂ and inhibiting its function, causing a release of these neurotransmitters into the synaptic cleft through their reuptake transporters.

Tachyphylaxis Tachyphylaxis (Greek ταχύς, ''tachys'', "rapid", and φύλαξις, ''phylaxis'', "protection") is a medical term describing an acute, sudden decrease in response to a drug after its administration; i.e. a rapid and short-term onset of drug to ...

and tolerance have been demonstrated with all drugs of this class. Benzphetamine has a

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...

of 4–6 hours.

Contraindications

Benzphetamine is contraindicated in patients with advanced arteriosclerosis, symptomatic cardiovascular disease, moderate to severe hypertension, hyper-thyroidism, known hypersensitivity or idiosyncrasy to sympathomimetic amines, and glaucoma, or who have recently used a

MAOI Monoamine oxidase inhibitors (MAOIs) are a class of drugs that inhibit the activity of one or both monoamine oxidase enzymes: monoamine oxidase A (MAO-A) and monoamine oxidase B (MAO-B). They are best known as effective antidepressants, especia ...

. Benzphetamine should not be given to patients who are in an agitated state or who have a history of drug abuse.

Controlled substance classification

Benzphetamine is unique in its classification as a Schedule III drug in the United States. (Most members of the amphetamine family are classified in the more highly regulated Schedule II.) Benzphetamine is metabolized by the human body into amphetamine and methamphetamine, making it one of a number of drugs to undergo

in vivo Studies that are ''in vivo'' (Latin for "within the living"; often not italicized in English) are those in which the effects of various biological entities are tested on whole, living organisms or cells, usually animals, including humans, and ...

conversion to a substance of higher addiction and abuse potential.

References

External links

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