Pimozide (Orap®) is an antipsychotic drug. As it has severe side effects, it is considered a drug of last resort, typically prescribed only after the patient has failed to respond to other medications. The side effects include tardive dyskinesia, neuroleptic malignant syndrome and long QT syndrome.

Uses

Pimozide is used in its oral preparation in schizophrenia, Gilles de la Tourette syndrome and chronic psychosis. In dermatology, it is used to treat delusions of parasitosis (the perception that one is infested with parasites).

Chemistry

Pimozide is a diphenylbutylpiperidine derivative.

Pharmacology

Pharmacokinetics

Plasma levels of pimozide can vary widely between patients, and in insufficient response therapeutic drug monitoring may be required to ascertain that the patient is developing adequate plasma levels before withdrawing the drug and attempting other antipsychotics

Pharmacodynamics

Pimozide is an inhibitor of the type 2 dopamine receptor (D2).

Side-effects

Pimozide has severe, potentially fatal side-effects. As with other dopamine antagonists Pimozide can cause tardive dyskinesia and neuroleptic malignant syndrome.

Reference

• Van Vloten WA. Pimozide: Use in Dermatology. Dermatol Online J 2003;9(2):3 (fulltext)

External link

• http://www.mentalhealth.com/drug/p30-o01.html (A medical white paper on its use)