Designer drugs are structural or functional analogues of controlled substances that are designed to mimic the pharmacological effects of the parent drug while avoiding detection or classification as illegal. Many of the older designer drugs (research chemicals) are structural analogues of psychoactive tryptamines or phenethylamines but there are many other chemically unrelated new psychoactive substances that can be considered part of the designer drug group. [1] [2] [3] [4] Designer drugs can also include substances that are not psychoactive in effect, such as analogues of controlled anabolic steroids and other performance and image enhancing drugs (PIEDs), including nootropics, weight loss drugs and erectile dysfunction medications. The pharmaceutical activities of these compounds might not be predictable based strictly upon structural examination. Many of the substances have common effects while structurally different or different effects while structurally similar due to SAR paradox. As a result of no real official naming for some of these compounds, as well as regional naming, this can all lead to potentially hazardous mix ups for users. [5] The following list is not exhaustive.
Androgenic anabolic steroids have approved medical uses as well as illicit use as performance-enhancing drugs to build muscle mass and strength. Anabolic steroids that have been designed to evade detection in sport doping tests are known as "designer steroids". [6] [7]
Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor ligands. They are intended to maintain the desirable muscle building effects of anabolic steroids while reducing undesirable androgenic actions (e.g., increased risk of prostate cancer). SARMs that are more selective in their action could potentially be used for a broader range of clinical indications other than the relatively limited legitimate uses that anabolic steroids are currently approved for. [8]
Empathogens are a class of psychoactive drugs that produce distinctive emotional and social effects similar to those of MDMA. Users of empathogens say the drugs often produce feelings of empathy, love, and emotional closeness to others.
Substituted methylenedioxyphenethylamines (MDxx) are a large chemical class of derivatives of the phenethylamines, which includes many psychoactive drugs that act as entactogens, psychedelics, and/or stimulants, as well as entheogens.
Benzofurans are similar in structure to MD(M)A but differ in that the methylenedioxy groups have been modified, removing one of the two oxygens in the methylenedioxy ring to render a benzofuran ring.
Indane and tetralin-type phenethylamines are vaguely related to their amphetamine analogues.
Only one non-tryptamine indole has been sold, 5-IT. It shows strong MAOI activity.
Drugs containing the tryptamine moiety are typically substrates for the serotonin receptors, in keeping with their close structural resemblance to serotonin, a neurotransmitter.
Substituted amphetamines are a chemical class of stimulants, entactogens, hallucinogens, and other drugs. They feature a phenethylamine core with a methyl group attached to the alpha carbon resulting in amphetamine, along with additional substitutions.
Drugs containing the phenethylamine moiety bear close structural resemblance to dopamine but substitution on the benzene ring gives rise to drugs with a much higher affinity for serotonin receptors.
Dissociatives are a class of hallucinogens which distort perceptions of sight and sound and produce feelings of detachment - dissociation - from the environment and self. This is done through reducing or blocking signals to the conscious mind from other parts of the brain. Although many kinds of drugs are capable of such action, dissociatives are unique in that they do so in such a way that they produce hallucinogenic effects, which may include sensory deprivation, dissociation, hallucinations, and dream-like states or trances. Some, which are nonselective in action and affect the dopamine and/or opioid systems, may be capable of inducing euphoria. Many dissociatives have general depressant effects and can produce sedation, respiratory depression, analgesia, anesthesia, and ataxia, as well as cognitive and memory impairment and amnesia.
Arylcyclohexylamines are the oldest and most widely used dissociatives. The class includes the well known anaesthetic, ketamine.
Diarylethylamines began to appear on grey markets only as recently as 2013.
Systematic reviews and meta-analyses of clinical research using low doses of certain central nervous system stimulants found that these drugs may enhance cognition in healthy people. [13] [14] [15] In particular, the classes of stimulants that demonstrate possible cognition-enhancing effects in humans have evidence in vitro as direct agonists or indirect agonists of dopamine receptor D1 or adrenoceptor A2. [13] [14] [16] [17] Relatively high doses of stimulants cause cognitive deficits. [16] [17]
Racetams, such as piracetam, oxiracetam, phenylpiracetam, and aniracetam, are often marketed as cognitive enhancers and sold over the counter. [24] [25] A 2019 study found that piracetam supplements sold in the United States were inaccurately labeled. [25] Racetams are often referred to as nootropics, but this property is not well established in humans, and nootropics are not consistently found in all racetams. [26] The racetams have poorly understood mechanisms, although piracetam and aniracetam are known to act as positive allosteric modulators of AMPA receptors and appear to modulate cholinergic systems. [27]
According to the FDA,
Piracetam is not a vitamin, mineral, amino acid, herb or other botanical, or dietary substance for use by humans to supplement the diet by increasing the total dietary intake. Further, piracetam is not a concentrate, metabolite, constituent, extract or combination of any such dietary ingredient. [...] Accordingly, these products are drugs, under section 201(g)(1)(C) of the Act, 21 U.S.C. § 321(g)(1)(C), because they are not foods and they are intended to affect the structure or any function of the body. Moreover, these products are new drugs as defined by section 201(p) of the Act, 21 U.S.C. § 321(p), because they are not generally recognized as safe and effective for use under the conditions prescribed, recommended, or suggested in their labeling. [28]
Some supposed nootropic substances are compounds and analogues of choline, a precursor of acetylcholine (a neurotransmitter) and phosphatidylcholine (a structural component of cell membranes).
PDE5 inhibitors are typically used to treat pulmonary hypertension and erectile dysfunction. [33]
GHRH analogues stimulate the release of growth hormone.
Agonists of the growth hormone secretagogue receptor stimulate the release of growth hormone through the ghrelin receptor.
Piperazine containing designer drugs have effects similar to MDMA (ecstasy). This class of drugs are mimics of serotonin that activate 5-HT receptor subtypes that release norepinephrine and dopamine.
A psychedelic substance is a psychoactive drug whose primary action is to alter cognition and perception. Psychedelics tend to affect and explore the mind in ways that result in the experience being qualitatively different from those of ordinary consciousness. The psychedelic experience is often compared to non-ordinary forms of consciousness such as trance, meditation, yoga, religious ecstasy, dreaming and even near-death experiences.
Lysergamides are amide derivatives of the alkaloid lysergic acid.
Drugs containing the tryptamine moiety are typically substrates for the serotonin receptors, in keeping with their close structural resemblance to serotonin, a neurotransmitter.
2C-x class of psychedelics are 2,5-dimethoxy-phenethylamine derivatives.
The DOx family of psychedelics are also known as "substituted amphetamines" as they contain the amphetamine backbone but are substituted on the benzene ring. This gives rise to serotonin agonists similar to the 2C-X class but more resistant to elimination in the body.
Sedatives are substances that induces sedation by reducing irritability or excitement. At higher doses they may result in slurred speech, staggering gait, poor judgment, and slow, uncertain reflexes. Doses of sedatives such as benzodiazepines, when used as a hypnotic to induce sleep, tend to be higher than amounts used to relieve anxiety, whereas only low doses are needed to provide a peaceful effect. Sedatives can be misused to produce an overly-calming effect. In the event of an overdose or if combined with another sedative, many of these drugs can cause unconsciousness and even death.
Opioids have pharmacologic actions resembling morphine and other components of opium.
Stimulants produce a variety of different kinds of effects by enhancing the activity of the central and peripheral nervous systems. Common effects, which vary depending on the substance and dosage in question, may include enhanced alertness, awareness, wakefulness, endurance, productivity, and motivation, increased arousal, locomotion, heart rate, and blood pressure, and the perception of a diminished requirement for food and sleep.
Amphetamines are a chemical class of stimulants, entactogens, hallucinogens, and other drugs. They feature a phenethylamine core with a methyl group attached to the alpha carbon resulting in amphetamine, along with additional substitutions.
Cathinones include some stimulants and entactogens, which are derivatives of cathinone. They feature a phenethylamine core with an alkyl group attached to the alpha carbon, and a ketone group attached to the beta carbon, along with additional substitutions.
Pyrrolidines are amphetamines with a pyrrolidine group. Pyrrolidinophenones (also called Pyrovalerones) are cathinones (βk-amphetamines) with a pyrrolidine group.
Thiophenes are stimulant drugs which are analogues of amphetamine or cathinone where the phenyl ring has been replaced by thiophene.
Tropane alkaloids occur in plants of the families erythroxylaceae (including coca). Piperidine and its derivatives are ubiquitous building blocks in the synthesis of many pharmaceuticals and fine chemicals.
Oxazolidines are a five-membered ring compounds consisting of three carbons, a nitrogen, and an oxygen. The oxygen and NH are the 1 and 3 positions, respectively. In oxazolidine derivatives, there is always a carbon between the oxygen and the nitrogen.
Phenylmorpholines are a class of stimulants containing a phenethylamine skeleton in which the terminal amine is incorporated into a morpholine ring.
Agonists of the central cannabinoid receptor type 1 mimic the behavioral effects of cannabis.
Indazole containing cannabinoid receptor agonists include:
Indole containing cannabinoid receptor agonists include:
MN 18 is an indazole-based synthetic cannabinoid that is an agonist for the cannabinoid receptors, with Ki values of 45.72 nM at CB1 and 11.098 nM at CB2 and EC50 values of 2.028 nM at CB1 and 1.233 nM at CB2, and has been sold online as a designer drug. It is the indazole core analogue of NNE1. Given the known metabolic liberation (and presence as an impurity) of amantadine in the related compound APINACA, it is suspected that metabolic hydrolysis of the amide group of MN-18 may release 1-naphthylamine, a known carcinogen. MN-18 metabolism has been described in literature.
AB-FUBINACA (AMB-FUBINACA) is a psychoactive drug that acts as a potent agonist for the cannabinoid receptors, with Ki values of 0.9 nM at CB1 and 23.2 nM at CB2 and EC50 values of 1.8 nM at CB1 and 3.2 nM at CB2. It was originally developed by Pfizer in 2009 as an analgesic medication but was never pursued for human use. In 2012, it was discovered as an ingredient in synthetic cannabinoid blends in Japan, along with a related compound AB-PINACA, which had not previously been reported.
ADB-FUBINACA (ADMB-FUBINACA) is a designer drug identified in synthetic cannabis blends in Japan in 2013. In 2018, it was the third-most common synthetic cannabinoid identified in drugs seized by the Drug Enforcement Administration.
AB-CHMINACA is an indazole-based synthetic cannabinoid. It is a potent agonist of the CB1 receptor (Ki = 0.78 nM) and CB2 receptor (Ki = 0.45 nM) and fully substitutes for Δ9-THC in rat discrimination studies, while being 16x more potent. Continuing the trend seen in other cannabinoids of this generation, such as AB-FUBINACA and AB-PINACA, it contains a valine amino acid amide residue as part of its structure, where older cannabinoids contained a naphthyl or adamantane residue.
5F-ADB (also known as MDMB-5F-PINACA and 5F-MDMB-PINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide family, which has been used as an active ingredient in synthetic cannabis products and has been sold online as a designer drug. 5F-ADB is a potent agonist of the CB1 receptor, though it is unclear whether it is selective for this target. 5F-ADB was first identified in November 2014 from post-mortem samples taken from an individual who had died after using a product containing this substance. Subsequent testing identified 5F-ADB to have been present in a total of ten people who had died from unexplained drug overdoses in Japan between September 2014 and December 2014. 5F-ADB is believed to be extremely potent based on the very low levels detected in tissue samples, and appears to be significantly more toxic than earlier synthetic cannabinoid drugs that had previously been sold.
AB-CHFUPYCA is a compound that was first identified as a component of synthetic cannabis products in Japan in 2015. The name "AB-CHFUPYCA" is an acronym of its systematic name N-(1-Amino-3-methyl-1-oxoButan-2-yl)-1-(CycloHexylmethyl)-3-(4-FlUorophenyl)-1H-PYrazole-5-CarboxAmide. There are two known regioisomers of AB-CHFUPYCA: 3,5-AB-CHMFUPPYCA (pictured) and 5,3-AB-CHMFUPPYCA. The article[1] refers to both 3,5-AB-CHMFUPPYCA and 5,3-AB-CHMFUPPYCA as AB-CHMFUPPYCA isomers, so AB-CHMFUPPYCA and AB-CHFUPYCA are not names for a unique chemical structure.
5F-AMB (also known as 5F-MMB-PINACA and 5F-AMB-PINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide family, which has been used as an active ingredient in synthetic cannabis products. It was first identified in Japan in early 2014. Although only very little pharmacological information about 5F-AMB itself exists, its 4-cyanobutyl analogue (instead of 5-fluoropentyl) has been reported to be a potent agonist for the CB1 receptor (KI = 0.7 nM).
5F-APINACA is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. Structurally it closely resembles cannabinoid compounds from patent WO 2003/035005 but with a 5-fluoropentyl chain on the indazole 1-position, and 5F-APINACA falls within the claims of this patent, as despite not being disclosed as an example, it is very similar to the corresponding pentanenitrile and 4-chlorobutyl compounds which are claimed as examples 3 and 4.
MDMB-FUBINACA (also known as MDMB(N)-Bz-F and FUB-MDMB) is an indazole-based synthetic cannabinoid that is a potent agonist for the cannabinoid receptors, with Ki values of 1.14 nM at CB1 and 0.1228 nM at CB2 and EC50 values of 0.2668 nM at CB1 and 0.1411 nM at CB2, and has been sold online as a designer drug. Its benzyl analogue (instead of 4-fluorobenzyl) has been reported to be a potent agonist for the CB1 receptor (Ki = 0.14 nM, EC50 = 2.42 nM). The structure of MDMB-FUBINACA contains the amino acid, 3-methylvaline or tert-leucine methyl ester.
PX-2 is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. It contains a phenylalanine amino acid amide as part of its structure.
APP-FUBINACA is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. Pharmacological testing showed APP-FUBINACA to have only moderate affinity for the CB1 receptor, with a Ki of 708 nM, while its EC50 was not tested. It contains a phenylalanine amino acid residue in its structure.
MMB-2201 is a potent indole-3-carboxamide based synthetic cannabinoid, which has been sold as a designer drug and as an active ingredient in synthetic cannabis blends. It was first reported in Russia and Belarus in January 2014, but has since been sold in a number of other countries. In the United States, MMB-2201 was identified in Drug Enforcement Administration drug seizures for the first time in 2018.
5F-ADB-PINACA is a cannabinoid designer drug that is an ingredient in some synthetic cannabis products. It is a potent agonist of the CB1 receptor and CB2 receptor with EC50 values of 0.24 nM and 2.1 nM respectively.
5F-AB-FUPPYCA (also known as AZ-037) is a pyrazole-based synthetic cannabinoid that is presumed to be an agonist of the CB1 receptor and has been sold online as a designer drug. It was first detected by the EMCDDA as part of a seizure of 540 g white powder in France in February 2015.
The Brazilian Controlled Drugs and Substances Act, officially Portaria nº 344/1998, is Brazil's federal drug control statute, issued by the Ministry of Health through its National Health Surveillance Agency (Anvisa). The act also serves as the implementing legislation for the Single Convention on Narcotic Drugs, the Convention on Psychotropic Substances, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances in the country.
MDMB-4en-PINACA is an indazole-based synthetic cannabinoid that has been sold online as a designer drug. MDMB-4en-PINACA was first identified in Europe in 2017. In 2021, MDMB-4en-PINACA was the most common synthetic cannabinoid identified by the Drug Enforcement Administration in the United States. MDMB-4en-PINACA differs from 5F-MDMB-PINACA due to replacement of 5-fluoropentyl with a pent-4-ene moiety (4-en).
4F-MDMB-BINACA (also known as MDMB-4F-BINACA, 4F-MDMB-BUTINACA or 4F-ADB) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide family. It should not be confused with the amantadine analogue 4F-ABINACA. It has been used as an active ingredient in synthetic cannabis products and sold as a designer drug since late 2018. 4F-MDMB-BINACA is an agonist of the CB1 receptor (EC50 = 7.39 nM), though it is unclear whether it is selective for this target. In December 2019, the UNODC announced scheduling recommendations placing 4F-MDMB-BINACA into Schedule II throughout the world.
ADB-BINACA (also known as ADMB-BZINACA using EMCDDA naming standards) is a cannabinoid designer drug that has been found as an ingredient in some synthetic cannabis products. It was originally developed by Pfizer as a potential analgesic, and is a potent agonist of the CB1 receptor with a binding affinity (Ki) of 0.33 nM and an EC50 of 14.7 nM.