SB-242084

Overview

SB-242084 is a selective serotonin 5-HT2C receptor antagonist which is used in scientific research.[1] WP

It has anxiolytic effects-like effects in rodents, and enhances dopamine signalling in the limbic system, as well as having complex effects on the dopamine release produced by cocaine, increasing it in some brain regions but reducing it in others. In animal studies, SB-242084 produced stimulant-type activity and reinforcing effects, somewhat similar to but much weaker than cocaine or amphetamines. It is self-administered by monkeys. The drug has been found to increase dopamine levels in the striatum in rats and in the nucleus accumbens in monkeys by about 200%. It potentiates the hyperlocomotion induced by amphetamine, methylphenidate, cocaine, MDMA, fenfluramine, nicotine, and morphine in rodents. Local injection of SB-242084 into the nucleus accumbens augments MDMA-induced conditioned place preference (CPP) and dopamine release in this area in rodents.[2–12] WP

The drug has been shown to increase the effectiveness of the selective serotonin reuptake inhibitor (SSRI) class of antidepressants in animals, and may also reduce their side effects. SSRIs acutely reduce social interaction in rodents, thought to be an anxiogenic response, and this effect can be reversed by SB-242084. SB-242084 has been found to reverse the anxiogenic effects of meta-chlorophenylpiperazine (mCPP) in rodents as well. In addition, SB-242084 reverses the acute hypolocomotion induced by SSRIs.[13–18] WP

SB-242084 was under development by GlaxoSmithKline for the treatment of anxiety disorders in the late 1990s. However, its development was abandoned. The drug reached the research or discovery phase of development prior to its discontinuation.[19][20] WP

Chemistry

Formula

C21H19ClN4O2 PC

CAS number

181632-25-7 PC

Molar mass (g/mol)

394.9 PC

IUPAC name (computed by PubChem)

6-chloro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-2,3-dihydroindole-1-carboxamide PC

SMILES

CC1=CC2=C(C=C1Cl)N(CC2)C(=O)NC3=CN=C(C=C3)OC4=C(N=CC=C4)C PC

InChIKey

GIUZEIJUFOPTMR-UHFFFAOYSA-N PC

PubChem CID

3644637

Harm reduction information

No harm reduction data is on file for this compound yet. That means no dose, timing or combination data from PsychonautWiki or TripSit. Please don't guess a dose from similar compounds. If you have taken it and feel unwell, contact emergency services or a poison control center.

User reports

Pop culture

No references added yet.

Sources

1. Journal / agency Kennett GA, Wood MD, Bright F, Trail B, Riley G, Holland V, Avenell KY, Stean T, Upton N, Bromidge S, Forbes IT, Brown AM, Middlemiss DN, Blackburn TP. SB 242084, a selective and brain penetrant 5-HT2C receptor antagonist. Neuropharmacology. 1997. doi:10.1016/S0028-3908(97)00038-5 · PMID 9225286
2. Journal / agency Martin JR, Ballard TM, Higgins GA. Influence of the 5-HT2C receptor antagonist, SB-242084, in tests of anxiety. Pharmacology, Biochemistry, and Behavior. April 2002. doi:10.1016/S0091-3057(01)00713-4 · PMID 11888553
3. Journal / agency Di Matteo V, Di Giovanni G, Di Mascio M, Esposito E. SB 242084, a selective serotonin2C receptor antagonist, increases dopaminergic transmission in the mesolimbic system. Neuropharmacology. August 1999. doi:10.1016/S0028-3908(99)00047-7 · PMID 10462132
4. Journal / agency Navailles S, De Deurwaerdère P, Porras G, Spampinato U. In vivo evidence that 5-HT2C receptor antagonist but not agonist modulates cocaine-induced dopamine outflow in the rat nucleus accumbens and striatum. Neuropsychopharmacology. February 2004. doi:10.1038/sj.npp.1300329 · PMID 14560323
5. Journal / agency Navailles S, Moison D, Ryczko D, Spampinato U. Region-dependent regulation of mesoaccumbens dopamine neurons in vivo by the constitutive activity of central serotonin2C receptors. Journal of Neurochemistry. November 2006. doi:10.1111/j.1471-4159.2006.04188.x · PMID 17018023
6. Journal / agency Navailles S, Moison D, Cunningham KA, Spampinato U. Differential regulation of the mesoaccumbens dopamine circuit by serotonin2C receptors in the ventral tegmental area and the nucleus accumbens: an in vivo microdialysis study with cocaine. Neuropsychopharmacology. January 2008. doi:10.1038/sj.npp.1301414 · PMID 17429406
7. Journal / agency Leggio GM, Cathala A, Moison D, Cunningham KA, Piazza PV, Spampinato U. Serotonin2C receptors in the medial prefrontal cortex facilitate cocaine-induced dopamine release in the rat nucleus accumbens. Neuropharmacology. February 2009. doi:10.1016/j.neuropharm.2008.10.005 · PMID 18977370 · PMC3130963
8. Journal / agency Manvich DF, Kimmel HL, Cooper DA, Howell LL. The serotonin 2C receptor antagonist SB 242084 exhibits abuse-related effects typical of stimulants in squirrel monkeys. The Journal of Pharmacology and Experimental Therapeutics. September 2012. doi:10.1124/jpet.112.195156 · PMID 22685342 · PMC3422522
9. Journal / agency Wold EA, Wild CT, Cunningham KA, Zhou J. Targeting the 5-HT2C Receptor in Biological Context and the Current State of 5-HT2C Receptor Ligand Development. Curr Top Med Chem. 2019. doi:10.2174/1568026619666190709101449 · PMID 31288724 · PMC6761005
10. Journal / agency Banks ML, Bauer CT, Blough BE, Rothman RB, Partilla JS, Baumann MH, Negus SS. Abuse-related effects of dual dopamine/serotonin releasers with varying potency to release norepinephrine in male rats and rhesus monkeys. Exp Clin Psychopharmacol. June 2014. doi:10.1037/a0036595 · PMID 24796848 · PMC4067459
11. Journal / agency Fletcher PJ, Sinyard J, Higgins GA. The effects of the 5-HT(2C) receptor antagonist SB242084 on locomotor activity induced by selective, or mixed, indirect serotonergic and dopaminergic agonists. Psychopharmacology (Berl). September 2006. doi:10.1007/s00213-006-0453-9 · PMID 16832658
12. Journal / agency Pomrenze MB, Vaillancourt S, Salgado JS, Raymond KB, Llorach P, Sacai H, Rijsketic DR, Hietamies TM, Touponse GC, Cardozo Pinto DF, Rastegar Z, Casey AB, Eshel N, Malenka RC, Heifets BD. 5-HT2C receptors in the nucleus accumbens constrain the rewarding effects of MDMA. Mol Psychiatry. November 2025. doi:10.1038/s41380-025-03128-4 · PMID 40707786 · PMC12532699
13. Journal / agency Cremers TI, Giorgetti M, Bosker FJ, Hogg S, Arnt J, Mørk A, Honig G, Bøgesø KP, Westerink BH, den Boer H, Wikstrom HV, Tecott LH. Inactivation of 5-HT(2C) receptors potentiates consequences of serotonin reuptake blockade. Neuropsychopharmacology. October 2004. doi:10.1038/sj.npp.1300474 · PMID 15138437
14. Journal / agency Burghardt NS, Bush DE, McEwen BS, LeDoux JE. Acute selective serotonin reuptake inhibitors increase conditioned fear expression: blockade with a 5-HT(2C) receptor antagonist. Biological Psychiatry. November 2007. doi:10.1016/j.biopsych.2006.11.023 · PMID 17524369 · PMC2129095
15. Journal / agency Bagdy G, Graf M, Anheuer ZE, Modos EA, Kantor S. Anxiety-like effects induced by acute fluoxetine, sertraline or m-CPP treatment are reversed by pretreatment with the 5-HT2C receptor antagonist SB-242084 but not the 5-HT1A receptor antagonist WAY-100635. Int J Neuropsychopharmacol. December 2001. doi:10.1017/S1461145701002632 · PMID 11806866
16. Journal / agency Dekeyne A, Denorme B, Monneyron S, Millan MJ. Citalopram reduces social interaction in rats by activation of serotonin (5-HT)(2C) receptors. Neuropharmacology. April 2000. doi:10.1016/s0028-3908(99)00268-3 · PMID 10727723
17. Journal / agency Yamauchi M, Tatebayashi T, Nagase K, Kojima M, Imanishi T. Chronic treatment with fluvoxamine desensitizes 5-HT2C receptor-mediated hypolocomotion in rats. Pharmacol Biochem Behav. August 2004. doi:10.1016/j.pbb.2004.05.003 · PMID 15301922
18. Journal / agency Shishkina GT, Iudina AM, Dygalo NN. Effects of fluoxetine on locomotor activity: possible involvement of dopamine. Zh Vyssh Nerv Deiat Im I P Pavlova. 2006. PMID 17025197
19. Journal / agency SB 242084. 26 July 2002
20. Other Delving into the Latest Updates on SB-242084 with Synapse. 13 June 2026

Text and values on this page are quoted from Wikipedia (CC BY-SA 4.0), PubChem (public domain). Each value links to the exact revision it came from.