Pimozide: Uses, Interactions and Safety

Uses

Pimozide is an antipsychotic with a particularly important heart rhythm and interaction profile. Turkish Nörofren labeling includes selected chronic schizophrenia treatment and motor or vocal tics in Tourette disorder that have not responded adequately to standard therapy. US approval is narrower, focusing on severely impairing Tourette tics after other treatment has failed.

Administration

Treatment is started and adjusted under close medical supervision. A baseline ECG and potassium assessment are important, with repeat ECGs during dose adjustment. Turkish labeling does not recommend treatment below twelve years. US pediatric wording is different and should not be substituted for local instructions.

Safety

Pimozide prolongs the QT interval. The Turkish label also prohibits use in depressive disorders, Parkinson syndrome and tics not associated with Tourette disorder. Congenital long QT, relevant arrhythmias, low potassium or magnesium and interacting medicines can make dangerous ventricular rhythms more likely. Fainting or a racing or irregular heartbeat requires urgent assessment. The medicine also carries antipsychotic risks such as persistent movement disorders and neuroleptic malignant syndrome.

Interactions

The label advises avoiding concurrent antipsychotics unless a specialist plans an exception or a supervised transition. Many combinations are contraindicated, including other QT-prolonging medicines and named antidepressants such as sertraline, citalopram, escitalopram and paroxetine. CYP3A4 or CYP2D6 inhibition can increase pimozide exposure. Macrolide antibiotics and several systemic antifungals require particular attention. Azithromycin is contraindicated by the US pimozide label despite differing from clarithromycin in enzyme effects. Topical ketoconazole shampoo is not treated as systemic ketoconazole. Avoid grapefruit juice. Diuretics that lower potassium require review, and sedatives increase impairment.

Pregnancy and breastfeeding

Pregnancy needs an individualized benefit–risk decision. Newborns exposed in the third trimester may have movement, withdrawal, breathing or feeding problems. Discuss an alternative feeding plan if pimozide is needed while breastfeeding.

Adverse effects

Sleepiness, dizziness, sweating, constipation and movement symptoms occur. Report new involuntary movements, fever with muscle stiffness, severe confusion or suspected overdose promptly.

Sources

• Pimozide Tablets, USP – US prescribing information (DailyMed updated 2026-07-10)
• Turkish product information: NÖROFREN 2 mg tablets (23.02.2017)
• ZYTIGA interaction information