Ritanserin (R 55667) is a highly potent, relatively selective, orally active, long acting antagonist of 5-HT2 receptor, with an IC50 of 0.9 nM, less active on Histamine H1, Dopamine D2, Adrenergic α1, Adrenergic α2 receptors[1].
Ritanserin (R 55667) is a highly potent, relatively selective, long acting antagonist of 5-HT2 receptor, with an IC50 of 0.9 nM, less active on Histamine-H1 (IC50, 35 nM), Dopamine-D2 (IC50, 70 nM), Adrenergic-α1 (IC50, 97 nM), Adrenergic-α2 receptor (IC50, 150 nM)[1].
References:
[1]. Leysen JE, et al. Receptor-binding properties in vitro and in vivo of ritanserin: A very potent and long acting serotonin-S2 antagonist. Mol Pharmacol. 1985 Jun;27(6):600-11.