5-APB (abbreviation of "5-(2-aminopropyl)benzofuran"; see infobox for the correct IUPAC name) is an empathogenic

psychoactive A psychoactive drug, psychopharmaceutical, psychoactive agent or psychotropic drug is a chemical substance, that changes functions of the nervous system, and results in alterations in perception, mood, consciousness, cognition or behavior. Th ...

compound of the substituted benzofuran,

substituted amphetamine Substituted amphetamines are a class of compounds based upon the amphetamine structure; it includes all derivative compounds which are formed by replacing, or substituting, one or more hydrogen atoms in the amphetamine core structure with sub ...

and

substituted phenethylamine Substituted phenethylamines (or simply phenethylamines) are a chemical class of organic compounds that are based upon the phenethylamine structure; the class is composed of all the derivative compounds of phenethylamine which can be formed by ...

classes. 5-APB and other compounds are sometimes informally called "Benzofury". 5-APB is commonly found as the succinate and hydrochloride salt. The hydrochloride salt is 10% more potent by mass and doses should be adjusted accordingly. 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. Des ...

since 2010.

Pharmacology

5-APB is a

serotonin–norepinephrine–dopamine reuptake inhibitor A serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI), also known as a triple reuptake inhibitor (TRI), is a type of drug that acts as a combined reuptake inhibitor of the monoamine neurotransmitters serotonin, norepinephrine, and ...

with ''K''_i(

NET Net or net may refer to: Mathematics and physics * Net (mathematics), a filter-like topological generalization of a sequence * Net, a linear system of divisors of dimension 2 * Net (polyhedron), an arrangement of polygons that can be folded up ...

)=180 nmol/L, ''K''_i( DAT)=265 nmol/L and ''K''_i( SERT)=811 nmol/L. It is also a serotonin–norepinephrine–dopamine releasing agent. 5-APB is a potent

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

for the 5-HT_2A and 5-HT_2B receptors (K_i of 14 nmol/L at 5-HT_2B with an efficacy of 0.924). This agonism for 5-HT_2B makes it likely that 5-APB would be cardiotoxic with long term use, as seen in other 5-HT_2B 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.https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/212102s003lb ...

and

MDMA 3,4-Methylenedioxymethamphetamine (MDMA), commonly seen in Tablet (pharmacy), tablet form (ecstasy) and crystal form (molly or mandy), is a potent empathogen–entactogen with stimulant properties primarily used for Recreational dru ...

. 5-APB is also an agonist of the 5-HT_2C receptor.

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 United States government tasked with the enforcement of federal law and administration of justice in the United State ...

and

DEA The Drug Enforcement Administration (DEA; ) is a United States federal law enforcement agency under the U.S. Department of Justice tasked with combating drug trafficking and distribution within the U.S. It is the lead agency for domestic en ...

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

Effects

Users describe effects as euphoric. Largely, effects reported were similar to that of the drug MDMA but not as strong. Recreational use of 5-APB has been associated with death in combination with other drugs and solely as the result of 5-APB. According to investigative reporting by David Nickles and Lily Kay Ross, a coroner's report identified "complications of 5-APB and other substance abuse" as the cause of death of Jen Rothman, who had been introduced to 5-APB by psychedelic practitioner

Jorge Ferrer Jorge N. Ferrer (born October 30, 1968) is a US-based Spanish psychologist who wrote about the applications of participatory theory to transpersonal psychology, religious studies, integral education, and sexuality and intimate relationships. F ...

. The reporters state that the mechanism of death was likely to have been

hyponatremia Hyponatremia or hyponatraemia is a low concentration of sodium in the blood. It is generally defined as a sodium concentration of less than 135 mmol/L (135 mEq/L), with severe hyponatremia being below 120 mEq/L. Symptoms can be abs ...

, caused by the increased action of serotonin induced by 5-APB. They note that telltale symptoms of hyponatremia, "Thirst, exhaustion, seizures, and vomiting erein Jen’s texts and the police report" pertaining to the incident. Such an effect has been documented for

, which has a similar mechanism of action and subjective effects.

Legality

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

{{Phenethylamines Substituted amphetamines 5-Benzofuranethanamines Designer drugs Serotonin-norepinephrine-dopamine releasing agents Serotonin receptor agonists Entactogens and empathogens