Pimozide

Overview

Pimozide, sold under the brand name Orap, is a typical antipsychotic medication of the diphenylbutylpiperidine class. It was discovered at Janssen Pharmaceutica in 1963. It is indicated for use in Tourette syndrome and resistant tics. It has a high potency compared to chlorpromazine (ratio 50–70:1). On a weight basis it is even more potent than haloperidol. WP

Uses, dosage and effects

Medical uses

Pimozide is used for Tourette syndrome, and resistant tics (Europe, United States, and Canada) and in Europe for schizophrenia, chronic psychosis, delusional disorder, and paranoid personality disorder.[1][2] WP

Risks and side effects

Contraindications

It is contraindicated in individuals with either acquired, congenital or a family history of QT interval prolongation. Its use is advised against in individuals with people with either a personal or a family history of arrhythmias or torsades de pointes. 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. 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. Likewise its use is contraindicated in individuals receiving treatment with CYP3A4, CYP1A2, or CYP2D6 inhibitors.[3] WP

Side effects

Very common (>10% frequency) side effects include:[3–6] WP

• Akinesia[3–6] WP
• Constipation[3–6] WP
• Dizziness[3–6] WP
• Dry mouth[3–6] WP
• Hyperhidrosis[3–6] WP
• Nocturia[3–6] WP
• Somnolence[3–6] WP
• Speech disorder[3–6] WP

Overdose

Pimozide overdose presents with severe extrapyramidal symptoms, hypotension, sedation, QT interval prolongation and ventricular arrhythmias including torsades de pointes. Gastric lavage, establishment of a patent airway and, if necessary, mechanically assisted respiration is the recommended treatment for pimozide overdose. Cardiac monitoring should be continued for at least 4 days due to the long half-life of pimozide.[3] WP

Pharmacology

Pharmacology

Pimozide acts as an antagonist of the D₂, D₃, and D₄ receptors and the 5-HT₇ receptor. It is also a hERG blocker. WP

Similarly to other typical antipsychotics pimozide has a high affinity for the dopamine D₂ receptor and this likely results in its sexual (due to prolactin hypersecretion) and extrapyramidal side effects as well as its therapeutic efficacy against the positive symptoms of schizophrenia.[7] WP⚠ A table follows this text in the source and is not copied here. Open the source to see it.

History

History

In 1985, pimozide was approved by the US Food and Drug Administration for marketing as an orphan drug for the treatment of Tourette syndrome.[1] WP

Chemistry

Formula

C28H29F2N3O PC

CAS number

2062-78-4 PC

Molar mass (g/mol)

461.5 PC

IUPAC name (computed by PubChem)

3-[1-[4,4-bis(4-fluorophenyl)butyl]piperidin-4-yl]-1H-benzimidazol-2-one PC

SMILES

C1CN(CCC1N2C3=CC=CC=C3NC2=O)CCCC(C4=CC=C(C=C4)F)C5=CC=C(C=C5)F PC

InChIKey

YVUQSNJEYSNKRX-UHFFFAOYSA-N PC

PubChem CID

16362

Harm reduction information

No harm reduction data is on file for this compound yet. That means no dose, timing or combination data from PsychonautWiki or TripSit. Please don't guess a dose from similar compounds. If you have taken it and feel unwell, contact emergency services or a poison control center.

User reports

Pop culture

No references added yet.

Sources

1. Journal / agency Colvin CL, Tankanow RM. Pimozide: use in Tourette's syndrome. Drug Intelligence & Clinical Pharmacy. June 1985. doi:10.1177/106002808501900602 · PMID 3891283
2. Other Munro A. Delusional disorder. 1999
3. Other Oral 4 mg tablets. - Summary of Product Characteristics. 2 April 2013
4. Other Oral (pimozide) dosing, indications, interactions, adverse effects, and more
5. Other Brayfield A. Pimozide. 12 February 2013
6. Journal / agency ORAP (pimozide) tablet [Teva Select Brands]. July 2012
7. Other Taylor D, Paton C, Shitij K. The Maudsley prescribing guidelines in psychiatry. 2012

Text and values on this page are quoted from Wikipedia (CC BY-SA 4.0), PubChem (public domain). Each value links to the exact revision it came from.