Haloperidol is a typical butyrophenone type antipsychotic that exhibits high affinity dopamine D 2 receptor antagonism and slow receptor dissociation kinetics.  It has effects similar to the phenothiazines .  The drug binds preferentially to D 2 and α 1 receptors at low dose (ED 50 = and mg/kg, respectively), and 5-HT 2 receptors at a higher dose (ED 50 = mg/kg). Given that antagonism of D 2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT 2 receptors on the negative symptoms, this characteristic underlies haloperidol's greater effect on delusions, hallucinations and other manifestations of psychosis.  Haloperidol's negligible affinity for histamine H 1 receptors and muscarinic M 1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic hypotension though having higher rates of treatment emergent extrapyramidal symptoms .
When people are in a manic "high," they may be overactive, overly talkative, have a great deal of energy, and have much less need for sleep than normal. They may switch quickly from one topic to another, as if they cannot get their thoughts out fast enough. Their attention span is often short, and they can be easily distracted. Sometimes people who are "high" are irritable or angry and have false or inflated ideas about their position or importance in the world. They may be very elated, and full of grand schemes that might range from business deals to romantic sprees. Often, they show poor judgment in these ventures. Mania, untreated, may worsen to a psychotic state.