Irdabisant (CEP-26401) is a selective, orally active and blood-brain barrier (BBB) penetrant histamine H3 receptor (H3R) inverse agonist/inverse agonist with K i values of 7.2 nM and 2.0 nM for rat H3R and human H3R, respectively. Irdabisant has relatively low inhibitory activity against hERG current with an IC 50 of 13.8 μM. Irdabisant has cognition-enhancing and wake-promoting activities in the rat social recognition model. Irdabisant can be used to research schizophrenia or cognitive impairment .