Quipazine: Classical hallucinogen? Novel psychedelic?

Quipazine, first identified in the 1960s, has been the topic of >1000 published papers. On the basis of available 5-HT₂ serotonin receptor radioligand binding data and various preclinical studies, it might be thought that quipazine bears the hallmarks of a classical hallucinogen or psychedelic agent - agents currently being examined for their potential use in treating certain neuropsychiatric disorders. Nevertheless, by definition, such agents require the availability of human data, which, in the case of quipazine, are lacking. Because quipazine is also a 5-HT₃ receptor agonist, future human studies with this agent might prove problematic because 5-HT₃ agonists are known to produce emesis. Nevertheless, continued investigation of novel quipazine analogs with modified pharmacological profiles might prove worthwhile. [ABSTRACT FROM AUTHOR]