iferanserin iferanserin iferanserin (inn; ven-309) is a drug which acts as a selective 5-ht2a receptor antagonist. it is under development as an intra-rectal formulation for the treatment of hemorrhoid disease, and as of february 2012, is in phase iib clinical trials. iferanserinclinical dataatc codenoneidentifiers iupac name (e)-n-ethyl]phenyl]-3-phenylprop-2-enamide cas number58754-46-4 ypubchem cid6445539chemspider4949235uniinwr3beb8pachemblchembl2107754chemical and physical dataformulac23h28n2omolar mass348.490 g·mol−13d model (jsmol)interactive image smiles o=c(\c=c\c1ccccc1)nc2ccccc2cc3n(c)cccc3 inchi inchi=1s/c23h28n2o/c1-25-18-8-7-12-21(25)16-15-20-11-5-6-13-22(20)24-23(26)17-14-19-9-3-2-4-10-19/h2-6,9-11,13-14,17,21h,7-8,12,15-16,18h2,1h3,(h,24,26)/b17-14+/t21-/m0/s1key:uxipfqubovwaqw-uebljokosa-n