A norepinephrine releasing agent (NRA), also known as an adrenergic releasing agent, is a catecholaminergic type of

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

that induces the

release Release may refer to: * Art release, the public distribution of an artistic production, such as a film, album, or song * Legal release, a legal instrument * News release, a communication directed at the news media * Release (ISUP), a code to i ...

norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic compound, organic chemical in the catecholamine family that functions in the brain and human body, body as a hormone, neurotransmitter and neuromodulator. The ...

(noradrenaline) and

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands a ...

(adrenaline) from the pre-synaptic neuron into the

synapse In the nervous system, a synapse is a structure that allows a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or a target effector cell. Synapses can be classified as either chemical or electrical, depending o ...

. This in turn leads to increased

extracellular This glossary of biology terms is a list of definitions of fundamental terms and concepts used in biology, the study of life and of living organisms. It is intended as introductory material for novices; for more specific and technical definitions ...

concentration In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: '' mass concentration'', '' molar concentration'', '' number concentration'', ...

s of norepinephrine and epinephrine therefore an increase in

adrenergic Adrenergic means "working on adrenaline (epinephrine) or noradrenaline (norepinephrine)" (or on their receptors). When not further qualified, it is usually used in the sense of enhancing or mimicking the effects of epinephrine and norepinephrine ...

neurotransmission Neurotransmission (Latin: ''transmissio'' "passage, crossing" from ''transmittere'' "send, let through") is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron ...

. A closely related type of drug is a norepinephrine reuptake inhibitor (NRI), for instance reboxetine. Another class of drugs that stimulates adrenergic activity is the adrenergic receptor agonist class.

Uses and examples

NRAs, frequently as norepinephrine–dopamine releasing agents (NDRAs) rather than as selective NRAs, are used for a variety of clinical indications including the following: * For the treatment of

attention deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...

(ADHD) — e.g.,

amphetamine Amphetamine (contracted from Alpha and beta carbon, alpha-methylphenethylamine, methylphenethylamine) is a central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, an ...

dextroamphetamine Dextroamphetamine (international nonproprietary name, INN: dexamfetamine) is a potent central nervous system (CNS) stimulant and enantiomer of amphetamine that is used in the treatment of attention deficit hyperactivity disorder (ADHD) and narc ...

levoamphetamine Levoamphetamine is a stimulant medication which is used in the treatment of certain medical conditions. It was previously marketed by itself under the brand name Cydril, but is now available only in combination drug, combination with dextroam ...

lisdexamfetamine Lisdexamfetamine, sold under the brand names Vyvanse and Elvanse among others, is a stimulant medication that is used as a treatment for attention deficit hyperactivity disorder (ADHD) in children and adults and for moderate-to-severe binge ...

methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...

* As

anorectic An anorectic is a drug that reduces appetite, resulting in lower food consumption, leading to weight loss. These substances work by affecting the central nervous system or certain neurotransmitters to create a feeling of fullness or reduce the desi ...

s in the treatment of

obesity Obesity is a medical condition, considered by multiple organizations to be a disease, in which excess Adipose tissue, body fat has accumulated to such an extent that it can potentially have negative effects on health. People are classifi ...

and binge-eating disorder — e.g., amphetamine,

phentermine Phentermine, sold under the brand name Adipex-P among others, is a medication used together with diet and exercise to treat obesity. It is available by itself or as the combination phentermine/topiramate. Phentermine is taken by mouth. Com ...

benzphetamine Benzphetamine, sold under the brand name Didrex among others, is an amphetamine-type stimulant and appetite suppressant used short-term for weight loss along with a doctor-approved, reduced-calorie diet, exercise, and behavioral program. It ...

phenmetrazine Phenmetrazine, sold under the brand name Preludin among others, is a stimulant drug first chemical synthesis, synthesized in 1952 and originally used as an appetite suppressant, but withdrawn drug, withdrawn from the market in the 1980s due to ...

, aminorex * As

wakefulness-promoting agent A wakefulness-promoting agent (WPA), or wake-promoting agent, is a drug that increases wakefulness and arousal. They are similar to but distinct from psychostimulants, which not only promote wakefulness but also produce other more overt central ...

s in the treatment of

narcolepsy Narcolepsy is a chronic neurological disorder that impairs the ability to regulate sleep–wake cycles, and specifically impacts REM (rapid eye movement) sleep. The symptoms of narcolepsy include excessive daytime sleepiness (EDS), sleep-r ...

— e.g., amphetamine, methamphetamine * As

nasal decongestant A decongestant, or nasal decongestant, is a type of pharmaceutical drug that is used to relieve nasal congestion in the upper respiratory tract. The active ingredient in most decongestants is either pseudoephedrine or phenylephrine (the latter o ...

s and

bronchodilator A bronchodilator or broncholytic (although the latter occasionally includes secretory inhibition as well) is a substance that dilates the bronchi and bronchioles, decreasing resistance in the respiratory airway and increasing airflow to the lun ...

s — e.g.,

levomethamphetamine Levomethamphetamine (International Nonproprietary Name, INN: levmetamfetamine) is an optical isomer of methamphetamine primarily used as a Topical decongestant, topical nasal decongestant. Levomethamphetamine is used to treat nasal congestion f ...

, propylhexedrine,

ephedrine Ephedrine is a central nervous system (CNS) stimulant and sympathomimetic agent that is often used to prevent hypotension, low blood pressure during anesthesia. It has also been used for asthma, narcolepsy, and obesity but is not the preferred ...

pseudoephedrine Pseudoephedrine, sold under the brand name Sudafed among others, is a sympathomimetic medication which is used as a decongestant to treat nasal congestion. It has also been used off-label for certain other indications, like treatment of lo ...

phenylpropanolamine Phenylpropanolamine (PPA), sold under many brand names, is a sympathomimetic agent used as a decongestant and appetite suppressant. It was once common in prescription and over-the-counter cough and cold preparations. The medication is taken ...

* Miscellaneous – e.g.,

amantadine Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended because ...

They are also used as

recreational drug Recreational drug use is the use of one or more psychoactive drugs to induce an altered state of consciousness, either for pleasure or for some other casual purpose or pastime. When a psychoactive drug enters the user's body, it induces an Sub ...

s, though this is typically reserved only for those that also induce the release of

dopamine Dopamine (DA, a contraction of 3,4-dihydroxyphenethylamine) is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. It is an amine synthesized ...

and/or

serotonin Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, ...

, for instance amphetamine, methamphetamine,

MDMA 3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy (tablet form), and molly (crystal form), is an empathogen–entactogenic drug with stimulant and minor Psychedelic drug, psychedelic properties. In studies, it has been used ...

, mephedrone, 4-methylaminorex, and MDAI, among others.

Cathine Cathine, also known as -norpseudoephedrine or as (+)-norpseudoephedrine, is a psychoactive drug of the phenethylamine and amphetamine groups which acts as a stimulant. Along with cathinone, it is found naturally in ''Catha edulis'' (khat), and ...

and

cathinone Cathinone (; also known as β-ketoamphetamine) is a monoamine alkaloid found in the shrub ''Catha edulis'' (khat) and is chemically similar to ephedrine, cathine, methcathinone and other amphetamines. It is probably the main contributor to t ...

are NRAs found naturally in ''

Catha edulis Khat (''Catha edulis''), also known as Bushman's tea, especially in South Africa, is a flowering plant native to eastern and southeastern Africa. It has a history of cultivation originating in the Harari Region, Harar area (present day easter ...

''. Ephedrine and pseudoephedrine are also found naturally in '' Ephedra sinica''. Both of these plants are used medicinally (and recreationally as well regarding the former). The endogenous

trace amine Trace amines are an endogenous group of trace amine-associated receptor 1 (TAAR1) agonists – and hence, monoaminergic neuromodulators – that are structurally and metabolically related to classical monoamine neurotransmitters. Compared to ...

phenethylamine Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace ami ...

and

tyramine Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine derived from the amino acid tyrosine. Tyramine acts as a catecholamine releasing agent. Notably, it is unable to cross the bl ...

are NRAs found in many animals, including humans. Selective NRAs include ephedrine, pseudoephedrine, phenylpropanolamine, levomethamphetamine, and D-phenylalaninol. These drugs also release dopamine to a much lesser extent however (e.g., ~10- to 20-fold less potently). No highly selective NRAs are currently known. Among the most selective known NRAs is ephedrine, which had about 19-fold higher potency for inducing norepinephrine release over dopamine release in one study. Levomethamphetamine has shown about 15-fold higher potency in inducing norepinephrine release over dopamine release. D-Phenylalaninol has 13-fold higher potency in inducing norepinephrine release over dopamine release. In contrast to levomethamphetamine,

is an NDRA, with only about 3-fold preference for inducing norepinephrine release over dopamine release in one study (versus

being roughly equipotent on norepinephrine and dopamine release in the same study). NRAs play a significant role in treating ADHD, obesity, narcolepsy, and as sympathomimetics by enhancing adrenergic signaling.

Mechanism of action

References

External links

* {{Monoamine releasing agents

Uses and examples

Mechanism of action

See also

References

External links