Cilansetron

Cilansetron is an experimental drug that is a 5-HT₃ antagonist under development by Solvay Pharmaceuticals.^[1][2][3]

Cilansetron

Clinical data
Other names	Calmactin; KC 9946
Pregnancy category	C
Routes of administration	Oral
ATC code	A03AE03 (WHO)
Legal status
Legal status	Unlicensed
Pharmacokinetic data
Bioavailability	87%
Metabolism	Hepatic
Elimination half-life	1.6 - 1.9 hours
Excretion	Renal
Identifiers
IUPAC name (10R)-10-[(2-Methyl-1H-imidazol-1-yl)methyl]-5,6,9,10-tetrahydro-4H-pyrido(3,2,1-jk)carbazol-11-one
CAS Number	120635-74-7 Y
PubChem CID	6918107
IUPHAR/BPS	2297
ChemSpider	5293321 Y
UNII	2J6DQ1U5B5
KEGG	D03495 Y
ChEMBL	ChEMBL2103778
CompTox Dashboard (EPA)	DTXSID40152951
Chemical and physical data
Formula	C20H21N3O
Molar mass	319.408 g·mol−1
3D model (JSmol)	Interactive image
SMILES O=C3c2c1cccc5c1n(c2CC[C@@H]3Cn4ccnc4C)CCC5
InChI InChI=1S/C20H21N3O/c1-13-21-9-11-22(13)12-15-7-8-17-18(20(15)24)16-6-2-4-14-5-3-10-23(17)19(14)16/h2,4,6,9,11,15H,3,5,7-8,10,12H2,1H3/t15-/m1/s1 Y Key:NCNFDKWULDWJDS-OAHLLOKOSA-N Y
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5-HT₃ receptors are responsible for causing many things from nausea to excess bowel movements. In conditions such as irritable bowel syndrome (IBS), the receptors have become faulty or oversensitive. 5-HT₃ antagonists work by blocking the nervous and chemical signals from reaching these receptors.

Studies have shown that the drug can improve quality of life in men and women with diarrhea-predominant IBS.^[4] Cilansetron is the first 5-HT antagonist specifically designed for IBS that is effective in men as well as women.^[4]

In 2005, Solvay received response from the U.S. Food and Drug Administration that cilansertron is not approvable without additional clinical trials;^[5][6] further development has been discontinued.^[7]