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Pimozide oral

Updated 2 Feb 2023 | Antipsychotics


Tablets containing pimozide

Drugs List

  • ORAP 4mg tablets
  • pimozide 4mg tablets
  • Therapeutic Indications


    Monosymptomatic hypochondrial psychosis
    Paranoid psychosis

    Treatment of symptoms and prevention of relapse in chronic schizophrenia.
    Other psychoses, including paranoid and monosymptomatic hypochondriacal psychoses (e.g. delusional parasitosis).

    Unlicensed Uses

    Gilles de la Tourette syndrome

    Gilles de la Tourette syndrome


    Dose should be individually determined, and is best initiated and titrated under close clinical supervision.

    In determining the initial dosage, consideration should be given to the patient's age, severity of symptoms and previous response to other neuroleptic drugs.

    Dose increases should be made at weekly intervals or longer, by increments of 2mg to 4mg in the daily dose.

    Maintenance dose should be the most effective dose at the lowest level possible.


    Chronic schizophrenia
    Initial dose: 2mg once daily. Increase, if necessary, according to response and tolerance.
    Maintenance dose: 2mg to 20mg once daily.

    Other psychoses, paranoid states and monosymptomatic hypochondrial psychoses (MHP)
    Initial dose: 4mg once daily. Increase, if necessary, according to response and tolerance.
    Maximum dose: 16mg once daily.


    Elderly patients require half the adult starting dose (See Dosage; Adult).


    Chronic schizophrenia
    Children aged 12 to 18 years
    (See Dosage; Adult)

    Other psychoses, paranoid states and monosymptomatic hypochondrial psychoses (MHP)
    Children aged 12 to 18 years
    (See Dosage; Adult)

    Tourette's syndrome (unlicensed)
    Children aged 12 to 18 years
    2mg to 10mg daily.

    Children aged 2 to 12 years
    1mg to 4mg daily.

    Patients with Renal Impairment

    The Renal Drug Handbook suggests:
    Glomerular filtration rate less than 10ml/minute: Start with a low dose, and increase according to response.


    Children under 2 years
    Family history of long QT syndrome
    Cardiac failure
    History of cardiac arrhythmias
    History of torsade de pointes
    Long QT syndrome
    Parkinson's disease
    Recent myocardial infarction
    Severe bradycardia
    Severe cardiac disorder
    Severe central nervous system depression

    Precautions and Warnings

    Children aged 2 to 12 years
    Predisposition to epileptic disorder
    Predisposition to prolongation of QT interval
    Alcohol withdrawal syndrome
    Benign prostatic hyperplasia
    Brain damage
    Cardiovascular disorder
    Electrolyte imbalance
    Epileptic disorder
    Haematological disorder
    Hepatic impairment
    History of jaundice
    History of seizures
    History of venous thromboembolism
    Myasthenia gravis
    Narrow angle glaucoma
    Non-cirrhotic alcoholic liver disease
    Respiratory disease
    Severe renal impairment

    Correct electrolyte disorders before treatment
    Reduce dose in patients with severe renal impairment
    Advise impaired alertness may affect ability to drive or operate machinery
    Treatment to be initiated and supervised by a specialist
    Perform ECG before treatment
    Elderly more susceptible to sedation, hypotensive & temp regulatory effects
    Monitor cardiac function during prolonged treatment
    Monitor ECG
    Monitor patients at risk for signs & symptoms of venous thromboembolism
    Monitor serum electrolytes
    Perform blood counts if unexplained infection or fever develops
    Fine vermicular movements of the tongue may be sign of tardive dyskinesia
    May cause or exacerbate extrapyramidal symptoms
    May impair ability to reduce core body temperature
    Potential for withdrawal symptoms
    Avoid abrupt withdrawal
    Discontinue if patient develops neuroleptic malignant syndrome
    Discontinue if tardive dyskinesia occurs
    Discontinue treatment if QTc exceeds 500msec
    If ECG changes or arrhythmias develop review and withdraw or reduce dose
    Maintain treatment at the lowest effective dose
    Reduce dose in elderly
    Advise that effects are potentiated by CNS depressants (including alcohol)
    Advise patient grapefruit products may increase plasma level
    Avoid direct exposure to sunlight

    Baseline ECG should be taken prior to commencing treatment, and then annually or more frequently thereafter. Treatment should be reviewed and either gradually withdrawn or the dose reduced under close supervision if the repolarization changes (prolongation of QT interval, T-wave changes or U-wave development) or arrhythmias develop. If QT or QTc exceeds 500 msec, discontinue pimozide.

    Consider possible risk factors for VTE before and during the treatment, preventive measures should be taken. Cases of venous thromboembolism have been reported (pulmonary embolism, deep vein thrombosis).

    Discontinue if unexplained fever occurs as this may be a sign of neuroleptic malignant syndrome associated with antipsychotic drugs (pallor, hyperthermia, autonomic dysfunction, altered consciousness, muscle rigidity). Signs of autonomic dysfunction such as sweating, tachycardia, and arterial instability may precede the onset of hyperthermia and serve as early warning signs. Perform blood counts if unexplained infection or fever develops.

    During treatment with pimozide, the bodies ability to reduce core temperature may be reduced as with other antipsychotics - caution should be observed in those exposed to extreme heat, dehydration or exercising strenuously. The elderly are particularly susceptible to postural hypotension and to hyperthermia and hypothermia in hot or cold weather.

    Data from studies showed a small risk of death in elderly people with dementia who are treated with antipsychotics. Not licensed for the treatment of dementia-related behavioural disturbances.

    Pregnancy and Lactation


    Pimozide should be used with caution in pregnancy.

    Safety in humans has not been established. Studies in animals have not demonstrated teratogenic effects. Some animal reproduction studies show decreased pregnancies, retarded foetal development, embryo toxicity and increased resorption. So it is recommended that pimozide should be avoided if possible, especially in the 1st trimester. However it should not be with held if it is the best drug for the patient.

    There are insufficient data from human exposures to exclude a risk of malformations or other risks to the foetus. Extrapyramidal effects have been reported in neonates with use of antipsychotics in the third trimester. If an infant has been exposed in utero to pimozide in the last trimester, observation of the neonate for adaptation problems, extrapyramidal and withdrawal symptoms for at least 2 days is recommended.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Pimozide is contraindicated in breastfeeding.

    Highly limited data is available on the secretion of pimozide into breast milk. The molecular weight (462) and prolonged elimination half-life suggest that the drug will be excreted into breast milk. If use is considered essential, breastfeeding should be discontinued as other drugs are prefered.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at


    Advise patients not to drink or eat grapefruit products.

    Advise patients alertness may be impaired and not to drive or operate machinery if so affected.

    Avoid alcohol.

    Photosensitisation may occur on high doses, avoid sunlight.

    Some medicines may interact with this medicine, including those available to purchase, patients should consult their doctor or pharmacist before self-medicating.

    Advise patients that an unexplained rise in body temperature may be an indicator of a rare reaction to the medicine, and that if affected, they should consult their physician immediately.

    During treatment with pimozide, the body's ability to reduce core temperature may be reduced - caution should be observed in those exposed to extreme heat, dehydration or exercising strenuously.

    Side Effects

    Antimuscarinic effects
    Blood dyscrasias
    Blurred vision
    Cardiac arrest
    Cholestatic jaundice
    Contact sensitisation
    Corneal opacities
    Difficulty in micturition
    Dry mouth
    ECG changes
    Erectile dysfunction
    Extrapyramidal effects
    Facial oedema
    Gastro-intestinal disturbances
    Grand mal seizure
    Impaired consciousness
    Increased prolactin
    Interference with temperature regulation
    Lens opacities
    Loss of libido
    Menstrual disturbances
    Muscle rigidity
    Muscle spasm
    Nasal congestion
    Neck stiffness
    Neuroleptic malignant syndrome
    Oculogyric crisis
    Oily skin
    Prolongation of QT interval
    Purplish pigmentation of cornea, conjunctiva, retina
    Purplish pigmentation of skin
    Sudden unexplained death
    Tardive dyskinesia
    Torsades de pointes
    Urinary frequency
    Urinary incontinence
    Venous thrombosis
    Ventricular fibrillation
    Ventricular tachycardia
    Weight gain


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: July 2015

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Medications and Mothers' Milk, Sixteenth Edition (2014) Hale, T and Rowe, H, Hale Publishing, Plano, Texas.

    Summary of Product Characteristics: Orap 4mg tablets. Eumedica S.A. Revised July 2016.

    The Renal Drug Handbook. Fourth Edition (2014) ed. Ashley, C and Dunleavy, A, Radcliffe Publishing Ltd, London.

    NICE Evidence Services Available at: Last accessed: 06 September 2017

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Pimozide Last revised: 10 March 2015
    Last accessed: 17 July 2015

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