Perlapine, sold under the brand names Hypnodine and Pipnodine, is a hypnotic and sedative of the tricyclic group which is marketed in Japan. It acts primarily as a potent antihistamine, and also has anticholinergic, antiserotonergic, antiadrenergic, and some antidopaminergic activity. The drug has relatively weak affinity for the dopamine D₂ receptor ( = 1,803 nM) and, in accordance, is said to be ineffective as an antipsychotic. However, it retains higher affinity for the dopamine D₁ receptor ( = 198 nM). Its values are 19 nM for the α₁-adrenergic receptor, 4,945 nM for the α₂-adrenergic receptor, and 70 nM for the serotonin 5-HT_2A receptor. Perlapine is closely related to clotiapine, clozapine, fluperlapine, loxapine, and tilozepine.