MDA is rarely sought as a recreational drug compared to other amphetamines; however, it remains widely used due to it being a primary metabolite,[3] the product of hepatic N-dealkylation,[4] of MDMA. It is also a common adulterant of illicitly produced MDMA.[5][6]
In terms of the subjective and behavioral effects of MDA, it is thought that serotonin release is required for its empathogenic effects, dopamine release is required for its euphoriant (rewarding and addictive) effects, dopamine and norepinephrine release is required for its psychostimulant effects, and direct agonism of the serotonin 5-HT2A receptor is required for its mild psychedelic effects.[medical citation needed]
In addition to its actions as a monoamine releasing agent, MDA is a potent high-efficacypartial agonist or full agonist of the rodent TAAR1.[20][21] Conversely, MDA is much weaker in terms of potency as an agonist of the human TAAR1.[20][21][27] Moreover, MDA acts as a very weak partial agonist or antagonist of the human TAAR1 rather than as an efficacious agonist.[20][21] TAAR1 activation is thought to auto-inhibit and constrain the effects of amphetamines that act as TAAR1 agonists, for instance MDMA in rodents.[28][29][30][31]
Activities of MDMA, its enantiomers, and related compounds
MDA may be quantitated in blood, plasma or urine to monitor for use, confirm a diagnosis of poisoning or assist in the forensic investigation of a traffic or other criminal violation or a sudden death. Some drug abuse screening programs rely on hair, saliva, or sweat as specimens. Most commercial amphetamine immunoassay screening tests cross-react significantly with MDA and major metabolites of MDMA, but chromatographic techniques can easily distinguish and separately measure each of these substances. The concentrations of MDA in the blood or urine of a person who has taken only MDMA are, in general, less than 10% those of the parent drug.[49][50][51]
MDA was first synthesized by Carl Mannich and W. Jacobsohn in 1910.[42] It was first ingested in July 1930 by Gordon Alles who later licensed the drug to Smith, Kline & French.[52] MDA was first used in animal tests in 1939, and human trials began in 1941 in the exploration of possible therapies for Parkinson's disease. From 1949 to 1957, more than five hundred human subjects were given MDA in an investigation of its potential use as an antidepressant and/or anorectic by Smith, Kline & French. The United States Army also experimented with the drug, code named EA-1298, while working to develop a truth drug or incapacitating agent. Harold Blauer died in January 1953 after being intravenously injected, without his knowledge or consent, with 450 mg of the drug as part of Project MKUltra. MDA was patented as an ataractic by Smith, Kline & French in 1960, and as an anorectic under the trade name "Amphedoxamine" in 1961. MDA began to appear on the recreational drug scene around 1963 to 1964. It was then inexpensive and readily available as a research chemical from several scientific supply houses. Several researchers, including Claudio Naranjo and Richard Yensen, have explored MDA in the field of psychotherapy.[53][54]
MDA is schedule 9 prohibited substance under the Poisons Standards.[57] A schedule 9 substance is listed as a "Substances which may be abused or misused, the manufacture, possession, sale or use of which should be prohibited by law except when required for medical or scientific research, or for analytical, teaching or training purposes with approval of Commonwealth and/or State or Territory Health Authorities."[57]
In 2010, the ability of MDA to invoke mystical experiences and alter vision in healthy volunteers was studied. The study concluded that MDA is a "potential tool to investigate mystical experiences and visual perception".[8]
A 2019 double-blind study administered both MDA and MDMA to healthy volunteers. The study found that MDA shared many properties with MDMA including entactogenic and stimulant effects, but generally lasted longer and produced greater increases in psychedelic-like effects like complex imagery, synesthesia, and spiritual experiences.[2]
^ abde la Torre R, Farré M, Roset PN, Pizarro N, Abanades S, Segura M, et al. (April 2004). "Human pharmacology of MDMA: pharmacokinetics, metabolism, and disposition". Therapeutic Drug Monitoring. 26 (2): 137–144. doi:10.1097/00007691-200404000-00009. PMID15228154.
^ abBaggott MJ, Siegrist J, Coyle JR, Flower K, Galloway G, Mendelson J (2010). "Poster Session III (PIII 1-84): PIII-09 Pharmacodynamic Effects of 3,4-Methylenedioxyamphetamine (MDA)". Clinical Pharmacology & Therapeutics. 87 (Suppl 1): S68–S95 (S70). doi:10.1038/clpt.2009.277. ISSN0009-9236. In a placebo-controlled, double-blind, within-subjects study, 12 individuals received a single 98 mg/70 kg bw dose of MDA. This is the molar equivalent of 105 mg/ 70 kg bw MDMA, a well-studied dose. [...] MDA increased cortisol by 16.39 ug/dL (95%CI: 13.03-19.74, P < 1e-3) and prolactin by 18.37 ng/mL (95%CI: 7.39-29.35, P < 1e-3). These hormonal changes are comparable to those seen after MDMA. Heart rate increased by 9.05 bpm (95%CI: 6.10-11.99, P < 1e-5) and blood pressure increased by 18.98 / 12.73 mm Hg (Systolic 95%CI: 16.47 - 21.49, P < 1e-7; Diastolic 95%CI: 10.82 - 14.63, P < 1e-4). [...] There were robust self-report VAS changes in both MDMA-like (e.g., "closeness to others") and hallucinogen-like (e.g., "familiar things seem unfamiliar", time distortions, closed-eye visuals) effects that were generally similar to those seen after MDMA. [...] MDA is a psychoactive sympathomimetic phenethylamine with effects similar to MDMA. Although differences may exist in the magnitude of physiological effects, the overall profiles appear remarkably similar.
^Nash JF, Roth BL, Brodkin JD, Nichols DE, Gudelsky GA (August 1994). "Effect of the R(−) and S(+) isomers of MDA and MDMA on phosphatidyl inositol turnover in cultured cells expressing 5-HT2A or 5-HT2C receptors". Neuroscience Letters. 177 (1–2): 111–115. doi:10.1016/0304-3940(94)90057-4. PMID7824160. S2CID41352480.
^Espinoza S, Gainetdinov RR (2014). "Neuronal Functions and Emerging Pharmacology of TAAR1". Taste and Smell. Vol. 23. Cham: Springer International Publishing. p. 175–194. doi:10.1007/7355_2014_78. ISBN978-3-319-48925-4. Interestingly, the concentrations of amphetamine found to be necessary to activate TAAR1 are in line with what was found in drug abusers [3, 51, 52]. Thus, it is likely that some of the effects produced by amphetamines could be mediated by TAAR1. Indeed, in a study in mice, MDMA effects were found to be mediated in part by TAAR1, in a sense that MDMA auto-inhibits its neurochemical and functional actions [46]. Based on this and other studies (see other section), it has been suggested that TAAR1 could play a role in reward mechanisms and that amphetamine activity on TAAR1 counteracts their known behavioral and neurochemical effects mediated via dopamine neurotransmission.
^Kuropka P, Zawadzki M, Szpot P (May 2023). "A narrative review of the neuropharmacology of synthetic cathinones-Popular alternatives to classical drugs of abuse". Hum Psychopharmacol. 38 (3): e2866. doi:10.1002/hup.2866. PMID36866677. Another feature that distinguishes [synthetic cathinones (SCs)] from amphetamines is their negligible interaction with the trace amine associated receptor 1 (TAAR1). Activation of this receptor reduces the activity of dopaminergic neurones, thereby reducing psychostimulatory effects and addictive potential (Miller, 2011; Simmler et al., 2016). Amphetamines are potent agonists of this receptor, making them likely to self‐inhibit their stimulating effects. In contrast, SCs show negligible activity towards TAAR1 (Kolaczynska et al., 2021; Rickli et al., 2015; Simmler et al., 2014, 2016). [...] It is worth noting, however, that for TAAR1 there is considerable species variability in its interaction with ligands, and it is possible that the in vitro activity of [rodent TAAR1 agonists] may not translate into activity in the human body (Simmler et al., 2016). The lack of self‐regulation by TAAR1 may partly explain the higher addictive potential of SCs compared to amphetamines (Miller, 2011; Simmler et al., 2013).
^Simmler LD, Buser TA, Donzelli M, Schramm Y, Dieu LH, Huwyler J, Chaboz S, Hoener MC, Liechti ME (January 2013). "Pharmacological characterization of designer cathinones in vitro". Br J Pharmacol. 168 (2): 458–470. doi:10.1111/j.1476-5381.2012.02145.x. PMC3572571. PMID22897747. β-Keto-analogue cathinones also exhibited approximately 10-fold lower affinity for the TA1 receptor compared with their respective non-β-keto amphetamines. [...] Activation of TA1 receptors negatively modulates dopaminergic neurotransmission. Importantly, methamphetamine decreased DAT surface expression via a TA1 receptor-mediated mechanism and thereby reduced the presence of its own pharmacological target (Xie and Miller, 2009). MDMA and amphetamine have been shown to produce enhanced DA and 5-HT release and locomotor activity in TA1 receptor knockout mice compared with wild-type mice (Lindemann et al., 2008; Di Cara et al., 2011). Because methamphetamine and MDMA auto-inhibit their neurochemical and functional effects via TA1 receptors, low affinity for these receptors may result in stronger effects on monoamine systems by cathinones compared with the classic amphetamines.
^Nagai F, Nonaka R, Satoh Hisashi Kamimura K (March 2007). "The effects of non-medically used psychoactive drugs on monoamine neurotransmission in rat brain". European Journal of Pharmacology. 559 (2–3): 132–137. doi:10.1016/j.ejphar.2006.11.075. PMID17223101.
^ abcBaggott MJ, Li L, Galloway GP, Scheidweiler KB, Barnes AJ, Huestis MA, Mendelson J (2012). "Poster Session III (PIII 1-110): PIII-110: Pharmacokinetics of Oral 3,4-Methylenedioxyamphetamine in Humans". Clinical Pharmacology & Therapeutics. 91 (Suppl 1): S96 –S135. doi:10.1038/clpt.2011.363. ISSN0009-9236. Knowledge of MDA and HMA kinetics in humans is limited to data from MDMA administration studies where minimal formation of these compounds likely leads to inaccurate parameter estimation. We administered a single [98 mg/70 kg body weight] oral dose of MDA to participants in a controlled setting to characterize plasma MDA pharmacokinetics for the first time. [...] Cmax and AUC0-∞ for MDA were 229 ± 39 ng/mL (mean ± SD) and 3636 ± 958 for MDA and 92 ± 61 ng/mL and 1544 ± 741 for the metabolite HMA. Total MDA clearance was 30267 ± 8214 mL/min. There was considerable between-subject variation in metabolite exposure: HMA Cmax and AUC varied over 7-fold and 4-fold, respectively, between the highest and lowest individuals. [...] Pharmacokinetics of MDA resemble those of an iso-molar dose of MDMA, suggesting differences in duration of acute effects between MDA and MDMA are not due to kinetic differences.
^Muszynski E (1961). "[Production of some amphetamine derivatives]". Acta Poloniae Pharmaceutica. 18: 471–478. PMID14477621.
^Noggle FT, DeRuiter J, Long MJ (1986). "Spectrophotometric and liquid chromatographic identification of 3,4-methylenedioxyphenylisopropylamine and its N-methyl and N-ethyl homologs". Journal of the Association of Official Analytical Chemists. 69 (4): 681–686. PMID2875058.
^Ho BT, McIsaac WM, An R, Tansey LW, Walker KE, Englert LF, Noel MB (January 1970). "Analogs of alpha-methylphenethylamine (amphetamine). I. Synthesis and pharmacological activity of some methoxy and/or methyl analogs". Journal of Medicinal Chemistry. 13 (1): 26–30. doi:10.1021/jm00295a007. PMID5412110.
^Butterick JR, Unrau AM (1974). "Reduction of β-nitrostyrene with sodium bis-(2-methoxyethoxy)-aluminium dihydride. A convenient route to substituted phenylisopropylamines". Journal of the Chemical Society, Chemical Communications. 8 (8): 307–308. doi:10.1039/C39740000307.
^Kolbrich EA, Goodwin RS, Gorelick DA, Hayes RJ, Stein EA, Huestis MA. Plasma pharmacokinetics of 3,4-methylenedioxymethamphetamine after controlled oral administration to young adults. Ther. Drug Monit. 30: 320–332, 2008.
^Naranjo C, Shulgin AT, Sargent T (1967). "Evaluation of 3,4-methylenedioxyamphetamine (MDA) as an adjunct to psychotherapy". Medicina et Pharmacologia Experimentalis. International Journal of Experimental Medicine. 17 (4): 359–364. doi:10.1159/000137100. PMID5631047.
^Yensen R, Di Leo FB, Rhead JC, Richards WA, Soskin RA, Turek B, Kurland AA (October 1976). "MDA-assisted psychotherapy with neurotic outpatients: a pilot study". The Journal of Nervous and Mental Disease. 163 (4): 233–245. doi:10.1097/00005053-197610000-00002. PMID972325. S2CID41155810.
Notes: (1) TAAR1 activity of ligands varies significantly between species. Some agents that are TAAR1 ligands in some species are not in other species. This navbox includes all TAAR1 ligands regardless of species. (2) See the individual pages for references, as well as the List of trace amines, TAAR, and TAAR1 pages. See also:Receptor/signaling modulators
