Pimozide (sold under the brand name Orap) is a neuroleptic drug of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It has a high potency compared to chlorpromazine (ratio 50-70:1). On a weight basis it is even more potent than haloperidol. It also has special indication for Tourette syndrome and resistant tics.

Pimozide is used for Tourette syndrome,^[2] and resistant tics (Europe, United States, and Canada) and in Europe for schizophrenia, chronic psychosis, delusional disorder, and paranoid personality disorder.^[3]

A 2013 systematic review compared pimozide with other antipsychotics for schizophrenia or related psychoses: Pimozide versus any other antipsychotic^[4]

In one case a series of 33 patients with delusional parasitosis (median age, 60 years), pimozide was prescribed for 24 patients, 18 of whom took the drug. The dose ranged from 1 to 5 mg daily. No information regarding initial dosing was specified, although the dose was continued for 6 weeks prior to tapering. Of those patients receiving pimozide, 61% (11/18) experienced improvement in or full remission of symptoms. The use of pimozide for the treatment of delusional parasitosis is based primarily on data from case series/reports that demonstrate some efficacy in the majority of patients. Currently, atypical antipsychotics such as olanzapine or risperidone are used as first line treatment. However, patients who experience negative side-effects with the first line medications are typically given pimozide.^[5][6]

It is contraindicated in individuals with either acquired, congenital or a family history of QT interval prolongation.^[7] Its use is advised against in individuals with people with either a personal or a family history of arrhythmias or torsades de pointes.^[7] Likewise its use is also advised against in individuals with uncorrected hypokalaemia and hypomagnesaemia or clinical significant cardiac disorders (e.g. a recent myocardial infarction or bradycardia.^[7] It is also contraindicated in individuals being cotreated with selective serotonin reuptake inhibitors (SSRI) or in those with a known hypersensitivity to pimozide or other diphenylbutyl-piperidine derivatives.^[7] Likewise its use is contraindicated in individuals receiving treatment with CYP3A4, CYP1A2, or CYP2D6 inhibitors.^[7]