<unk> , 10-mg oral tablet<unk>  is a typical butyrophenone type antipsychotic that exhibits<unk> igh affinity dopamine D2 receptor antagonism and slow receptor dissociation kinetics. It<unk> as effects similar to the phenothiazines. The drug binds preferentially to D2 and α1 receptors at low dose (ED50 = 0.13 and 0.42 mg/kg, respectively), and 5-HT2 receptors at a<unk> igher dose (ED50 = 2.6 mg/kg). Given that antagonism of D2 receptors is more beneficial on the positive symptoms of schizophrenia and antagonism of 5-HT2 receptors on the negative symptoms, this characteristic underlies<unk> 's greater effect on delusions,<unk> allucinations and other manifestations of psychosis.<unk> 's negligible affinity for<unk> istamine<unk> 1 receptors and muscarinic M1 acetylcholine receptors yields an antipsychotic with a lower incidence of sedation, weight gain, and orthostatic<unk> ypotension though<unk> aving<unk> igher rates of treatment emergent extrapyramidal symptoms.<unk>  acts on these receptors: (Ki) * D1 (silent antagonist) – Unknown efficiency * D5 (silent antagonist) – Unknown efficiency * D2 (inverse agonist) – 0.7 nM * D3 (inverse agonist) – 0.2 nM * D4 (inverse agonist) – 5–9 nM * σ1 (irreversible inactivation by<unk>  metabolite<unk> PP+) – 3 nM * σ2 (agonist): 54 nM * 5HT1A receptor agonist – 1927 nM * 5HT2A (silent antagonist) – 53 nM * 5HT2C (silent antagonist) – 10,000 nM * 5HT6 (silent antagonist) – 3666 nM * 5HT7 (irreversible silent antagonist) – 377.2 nM *<unk> 1 (silent antagonist) – 1,800 nM * M1 (silent antagonist) – 10,000 nM * α1A (silent antagonist) – 12 nM * α2A (silent antagonist) – 1130 nM * α2B (silent antagonist) – 480 nM * α2C (silent antagonist) – 550 nM * NR1/NR2B subunit containing NMDA receptor (antagonist; ifenprodil site): IC50 – 2,000 nM
Haloperidol
Chlorpromazine
Domperidone
Sertindole
Iprindole
Desmethylclozapine
Thioridazine
Pirlindole