israpafant israpafant israpafant (y-24180) is a drug which acts as a selective antagonist for the platelet-activating factor receptor, and was originally developed for the treatment of asthma. its chemical structure is a thienotriazolodiazepine, closely related to the sedative benzodiazepine derivative etizolam. however israpafant binds far more tightly to the platelet-activating factor receptor, with an ic50 of 0.84nm for inhibiting paf-induced human platelet aggregation (compared to etizolam's ic50 of 998nm at this target), while it binds only weakly to benzodiazepine receptors, with a ki of 3680nm. israpafant has been found to inhibit the activation of eosinophil cells, and consequently delays the development of immune responses. it has also been shown to have anti-nephrotoxic properties, and to mobilize calcium transport. israpafantlegal statuslegal status us: investigational new drug identifiers iupac name (6r)-4-(2-chlorophenyl)-2--6,9-dimethyl-6h-thienotriazolodiazepine cas number117279-73-9 ypubchem cid636426chemspider552203uniio3mcv749swchemical and physical dataformulac28h29cln4smolar mass489.08 g·mol−13d model (jsmol)interactive image smiles c1c2=nn=c(n2c3=c(c=c(s3)ccc4=cc=c(c=c4)cc(c)c)c(=n1)c5=cc=cc=c5cl)c inchi inchi=1s/c28h29cln4s/c1-17(2)15-21-11-9-20(10-12-21)13-14-22-16-24-26(23-7-5-6-8-25(23)29)30-18(3)27-32-31-19(4)33(27)28(24)34-22/h5-12,16-18h,13-15h2,1-4h3/t18-/m1/s1key:rmswmrjvujsdgn-gosisdbhsa-n