5-APB (abbreviation of "5-(2-aminopropyl)benzofuran") is an empathogenic

psychoactive A psychoactive drug, psychopharmaceutical, mind-altering drug, consciousness-altering drug, psychoactive substance, or psychotropic substance is a chemical substance that alters psychological functioning by modulating central nervous system acti ...

compound of the

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 ...

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 ...

, and

benzofuran Benzofuran is the heterocyclic compound consisting of fused benzene and furan rings. This colourless liquid is a component of coal tar. Benzofuran is the structural nucleus (parent compound) of many related compounds with more complex stru ...

families. The drug and other compounds have sometimes been informally called "Benzofury". 5-APB has been sold as a

designer drug A designer drug is a structural or functional analog of a controlled substance that has been designed to mimic the pharmacological effects of the original drug, while avoiding classification as illegal and/or detection in standard drug tests. ...

since 2010.

Effects

Users describe the effects of 5-APB as including

euphoria Euphoria ( ) is the experience (or affect) of pleasure or excitement and intense feelings of well-being and happiness. Certain natural rewards and social activities, such as aerobic exercise, laughter, listening to or making music and da ...

among others. Largely, its effects reported were similar to those of the drug

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 ...

but not as strong. The drug has been reported to produce visual disturbances and is said to have mild psychedelic effects. Recreational use of 5-APB has been associated with death in combination with other drugs and solely as the result of 5-APB.

Pharmacology

5-APB acts as a

serotonin–norepinephrine–dopamine releasing agent A serotonin–norepinephrine–dopamine releasing agent (SNDRA), also known as a triple releasing agent (TRA), is a type of drug which induces the release of serotonin, norepinephrine/epinephrine, and dopamine in the brain and body. SNDRAs produc ...

(SNDRA), with values for monoamine release of 19nM for

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, ...

, 21nM for

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 ...

, and 31nM for

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 ...

in rat brain synaptosomes. It is also a serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI). 5-APB is a potent

agonist An agonist is a chemical that activates a Receptor (biochemistry), receptor to produce a biological response. Receptors are Cell (biology), cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an R ...

of the

5-HT_2A and 5-HT_2B receptors. Its () values were 6,300nM (54%) at the serotonin 5-HT_2A receptor and 280nM (61–92%) at the serotonin 5-HT_2B receptor. It also shows

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Pa ...

for the serotonin 5-HT_2C receptor (K_i = 880nM) and the serotonin 5-HT_1A receptor (K_i = 3,300nM). It has been reported to act as an agonist of the serotonin 5-HT_2C receptor similarly to the serotonin 5-HT_2A and 5-HT_2B receptors. The drug's potent agonism of the serotonin 5-HT_2B receptor makes it likely that 5-APB would be

cardiotoxic Cardiotoxicity is the occurrence of heart dysfunction as electric or muscle damage, resulting in heart toxicity. This can cause heart failure, arrhythmia, myocarditis, and cardiomyopathy in patients. Some effects are reversible, while in others, p ...

with long-term use, as seen with other serotonin 5-HT_2B receptor agonists such as

fenfluramine Fenfluramine, sold under the brand name Fintepla, is a serotonergic medication used for the treatment of seizures associated with Dravet syndrome and Lennox–Gastaut syndrome. It was formerly used as an appetite suppressant in the treat ...

and

. 5-APB also shows high affinity for the mouse and rat

trace amine-associated receptor 1 Trace amine-associated receptor 1 (TAAR1) is a trace amine-associated receptor (TAAR) protein that in humans is encoded by the ''TAAR1'' gene. TAAR1 is a primarily intracellular amine-activated and G protein-coupled receptor (GPCR) that is p ...

(TAAR1). In

animal studies Animal studies is a recently recognised field in which animals are studied in a variety of cross-disciplinary ways. Scholars who engage in animal studies may be formally trained in a number of diverse fields, including art history, anthropology ...

, 5-APB produces robust hyperlocomotion, robust conditioned place preference (CPP) but limited

self-administration Self-administration is, in its Medicine, medical sense, the process of a subject administering a Pharmacology, pharmacological substance to themself. A clinical example of this is the subcutaneous "self-injection" of insulin by a Diabetes, diabetic ...

, fully substitutes for

in drug discrimination tests, and partially substitutes for DOM,

cocaine Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...

, and

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 ...

in drug discrimination tests.

Chemistry

5-APB is commonly found as the

succinate Succinic acid () is a dicarboxylic acid with the chemical formula (CH2)2(CO2H)2. In living organisms, succinic acid takes the form of an anion, succinate, which has multiple biological roles as a metabolic intermediate being converted into Fuma ...

and

hydrochloride In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (e.g. an amine). An alternative name is chlorhydrate, which comes from French. An archaic alternati ...

salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more formally called table salt. In the form of a natural crystalline mineral, salt is also known as r ...

. The hydrochloride salt is 10% more potent by mass and doses should be adjusted accordingly.

Detection

A forensic standard of 5-APB is available, and the compound has been posted on the Forendex website of potential drugs of abuse. The

US Department of Justice The United States Department of Justice (DOJ), also known as the Justice Department, is a federal executive department of the U.S. government that oversees the domestic enforcement of federal laws and the administration of justice. It is equ ...

and DEA have also conducted studies concerning the detection of 5-APB.

Society and culture

Legal status

United Kingdom

On March 5, 2014 the UK Home Office announced that 5-APB would be made a class B drug on 10 June 2014 alongside every other benzofuran entactogen and many structurally related drugs.

References

{{Chemical classes of psychoactive drugs 5-HT2A agonists 5-HT2B agonists 5-HT2C agonists 5-Benzofuranethanamines Designer drugs Entactogens Psychedelic phenethylamines Serotonin-norepinephrine-dopamine releasing agents Serotonin receptor agonists Stimulants Substituted amphetamines TAAR1 modulators