Irdabisant (CEP-26401) is a selective, orally active and blood-brain barrier (BBB) penetrant histamine H3 receptor (H3R) inverse agonist/inverse agonist with Ki 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 IC50 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[1][2].
Irdabisant (CEP-26401, compound 8a) shows antagonist activity with Kb, app values of 1.0 nM and 0.4 nM for rat H3R and human H3R, respectively; shows inverse agonist activity with EC50 values of 2.0 nM and 1.1 nM for rat H3R and human H3R, respectively[1].
Irdabisant has moderate activity at Muscarinic M2 (Ki = 3.7 ± 0.0 μM) and Adrenergic α1A (Ki = 9.8 ± 0.3 μM) receptors, Dopamine transporters (Ki = 11 ± 2 μM), Norepinephrine transporters (Ki = 10 ± 1 μM), and phosphodiesterase PDE3 (IC50 = 15 ± 1 μM)[1].
Irdabisant inhibits the cytochrome P450 enzymes CYP1A2, 2C9, 2C19, 2D6, and 3A4 with IC50 values of greater than 30 μM, indicating less potential for drug-drug interactions[1].
CEP-26401 (0.01-0.3 mg/kg; p.o.; single dosage) dose-dependently inhibits H3R agonist
[1]. Hudkins RL, et al. Discovery and characterization of 6-{4-[3-(R)-2-metlpyrrolidin-1-yl)propoxy]phenyl}-2H-pyridazin-3-one (CEP-26401, irdabisant): a potent, selective histamine H3 receptor inverse agonist. J Med Chem. 2011 Jul 14;54(13):4781-92.
[2]. Raddatz R, et al. CEP-26401 (irdabisant), a potent and selective histamine H? receptor antagonist/inverse agonist with cognition-enhancing and wake-promoting activities. J Pharmacol Exp Ther. 2012 Jan;340(1):124-33.