Clinical data
Other namesSB-204,741
  • N-(1-Methyl-1H-indol-5-yl)-N'-(3-methylisothiazol-5-yl)urea
CAS Number
PubChem CID
CompTox Dashboard (EPA)
ECHA InfoCard100.150.276 Edit this at Wikidata
Chemical and physical data
Molar mass286.35 g·mol−1
3D model (JSmol)
  • c2c(C)nsc2NC(=O)Nc3ccc1n(C)ccc1c3
  • InChI=1S/C14H14N4OS/c1-9-7-13(20-17-9)16-14(19)15-11-3-4-12-10(8-11)5-6-18(12)2/h3-8H,1-2H3,(H2,15,16,19)

SB-204741 is a drug which acts as a potent and selective antagonist at the serotonin 5-HT2B receptor, with around 135x selectivity over the closely related 5-HT2C receptor, and even higher over the 5-HT2A receptor and other targets.[1] It is used in scientific research for investigating the functions of the 5-HT2B receptor.[2][3][4][5]


  1. ^ Forbes IT, Jones GE, Murphy OE, Holland V, Baxter GS (March 1995). "N-(1-methyl-5-indolyl)-N'-(3-methyl-5-isothiazolyl)urea: a novel, high-affinity 5-HT2B receptor antagonist". Journal of Medicinal Chemistry. 38 (6): 855–7. doi:10.1021/jm00006a001. PMID 7699699.
  2. ^ Glusa E, Pertz HH (June 2000). "Further evidence that 5-HT-induced relaxation of pig pulmonary artery is mediated by endothelial 5-HT(2B) receptors". British Journal of Pharmacology. 130 (3): 692–8. doi:10.1038/sj.bjp.0703341. PMC 1572101. PMID 10821800.
  3. ^ Holohean AM, Hackman JC (October 2004). "Mechanisms intrinsic to 5-HT2B receptor-induced potentiation of NMDA receptor responses in frog motoneurones". British Journal of Pharmacology. 143 (3): 351–60. doi:10.1038/sj.bjp.0705935. PMC 1575347. PMID 15339859.
  4. ^ Papageorgiou A, Denef C (September 2007). "Stimulation of growth hormone release by 5-hydroxytryptamine (5-HT) in cultured rat anterior pituitary cell aggregates: evidence for mediation by 5-HT2B, 5-HT7, 5-HT1B, and ketanserin-sensitive receptors". Endocrinology. 148 (9): 4509–22. doi:10.1210/en.2007-0034. PMID 17584957.
  5. ^ Wouters MM, Gibbons SJ, Roeder JL, Distad M, Ou Y, Strege PR, et al. (September 2007). "Exogenous serotonin regulates proliferation of interstitial cells of Cajal in mouse jejunum through 5-HT2B receptors" (PDF). Gastroenterology. 133 (3): 897–906. doi:10.1053/j.gastro.2007.06.017. PMID 17854596.