tricyclic dibenzodiazepine, classified as an atypical antipsychotic agent; binds several types of central nervous system receptors, and displays a unique pharmacological profile; it is a serotonin antagonist, with strong binding to 5-HT 2A/2C receptor subtype, and also displays strong affinity to several dopaminergic receptors, but shows only weak antagonism at the dopamine D2 receptor, a receptor commonly thought to modulate neuroleptic activity; agranulocytosis is a major adverse effect associated with administration of this agent.