piboserod piboserod piboserod is a selective 5-ht4 receptor antagonist which was marketed and manufactured by glaxosmithkline (gsk) under the trade name serlipet for the management of atrial fibrillation and irritable bowel syndrome. in 2007 the norwegian company bio-medisinsk innovasjon as (bmi) completed a clinical phase ii study to investigate the effect of piboserod in patients with chronic heart failure. piboserodclinical datatrade namesserlipetroutes ofadministrationoralatc codenonelegal statuslegal status clinical phase ii identifiers iupac name n-((1-butyl-4-piperidyl)-methyl)-3,4-dihydro-2h-(1,3)oxazino(3,2-a)indole-10-carboxamide cas number152811-62-6 ypubchem cid177336iuphar/bps225chemspider154413 nunii4uq3s81b25chemblchembl356359 ncomptox dashboard (epa)dtxsid60165129 chemical and physical dataformulac22h31n3o2molar mass369.509 g·mol−13d model (jsmol)interactive image smiles ccccn1ccc(cnc(=o)c2c3n(c4ccccc24)ccco3)cc1 inchi inchi=1s/c22h31n3o2/c1-2-3-11-24-13-9-17(10-14-24)16-23-21(26)20-18-7-4-5-8-19(18)25-12-6-15-27-22(20)25/h4-5,7-8,17h,2-3,6,9-16h2,1h3,(h,23,26) nkey:kvcsjpatkxabrq-uhfffaoysa-n n ny (what is this?) (verify) mechanism of action in 2002 a research group at the university of oslo discovered that muscles from the ventricle of failing hearts have increased responsiveness to serotonin. they later demonstrated that the effect was due to an expression of functional 5-ht4 receptors in the failing muscle. on the basis of these findings, and in analogy with the success of betablockers in heart failure, the group made the hypothesis that 5-ht4 receptor antagonists could be useful to treat heart failure. their hypothesis was tested in animal models of heart failure with positive results.