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Zuclopenthixol acetate

Updated 2 Feb 2023 | Antipsychotics


Oily injection containing 50mg/ml zuclopenthixol (5% zuclopenthixol acetate equivalent to 4.526% of zuclopenthixol base)

Drugs List

  • CLOPIXOL ACUPHASE 50mg/1ml oily injection
  • zuclopenthixol acetate 50mg/1ml oily injection
  • Therapeutic Indications


    For the initial treatment of acute psychoses including mania and exacerbation of chronic psychoses, where a rapid onset of action is required with a duration of effect of 2-3 days.

    Only recommended for short term use.



    Dosage should be adjusted according to the severity of the patient's illness.

    The usual dose is 50-150mg repeated if necessary after 2 or 3 days. Some patients may need an additional injection between 1 and 2 days after the first dose.

    Not recommended for long term use, treatment duration should not exceed 2 weeks with maximum accumulated dose in a course less than 400 mg with no more than 4 injections.


    Dosage may need to be reduced in elderly patients owing to reduced rates of metabolism and elimination.

    Maximum dosage per injection should be 100mg.

    The elderly require close supervision as they are specially susceptible to adverse effects - sedation, hypotension, confusion, temperature changes.


    Not recommended


    Not recommended

    Patients with Renal Impairment

    The manufacturer recommends no dose reduction in patients with impaired renal function, but a reduction to half the normal dose in renal failure.

    The Renal Drug Handbook suggests:
    GFR above 10ml/min - dose as in normal renal function
    GFR < 10 ml/min - start with 50% of the dose and titrate slowly

    Patients with Hepatic Impairment

    Half dose should be used for patients with hepatic impairment.

    Serum-level monitoring is recommended.

    Additional Dosage Information

    A single injection of zuclopenthixol acetate oily injection has an onset of action shortly after administration and a duration of treatment of 2 to 3 days. During this period, maintenance therapy, with a different antipsychotic, may be initiated.

    Maintenance treatment can be continued using zuclopenthixol dihydrochloride tablets, or a longer acting depot zuclopenthixol decanoate injection.

    Guidelines for transferring patients on to maintenance therapy are as follows:
    Introduce zuclopenthixol dihydrochloride tablets at a dosage of 20-60mg/day in divided doses, 2 to 3 days after the last injection. If necessary increase the tablet dosage by 10-20mg each day up to a maximum of 150mg/day.
    Concurrently with the last injection, administer 200-500mg of a longer acting depot injection of zuclopenthixol decanoate by deep intramuscular injection, and repeat the injection at intervals of 2 to 4 weeks. Higher doses or a shorter interval may be necessary.


    For intramuscular administration.

    Zuclopenthixol oily injection should be administered by deep intramuscular injection into the upper outer buttock or lateral thigh.


    Circulatory collapse
    Depressed level of consciousness - (e.g. acute alcohol, barbiturate or opioid intoxication)
    Children under 18 years
    Pregnancy - see Pregnancy
    Breastfeeding - see Lactation
    Apathetic or withdrawn states

    Precautions and Warnings

    Use with caution in:
    Cardiac disease
    Severe respiratory disease
    Hepatic impairment - see Renal impairment
    Renal failure - see Hepatic impairment
    Epilepsy and conditions predisposing to epilepsy
    Parkinson's disease
    Angle closure glaucoma
    Prostatic hypertrophy
    Myasthenia gravis
    Organic brain syndrome
    Mental retardation
    Opiate abuse
    Alcohol abuse

    Elderly - see Dosage, Elderly
    The elderly are more likely to experience adverse effects such as sedation, hypotension, confusion and body temperature changes.

    As with others antipsychotics zuclopenthixol should be used with caution in patients with risk factors for cerebrovascular accidents. Cerebrovascular adverse events have been reported in clinical trials with antipsychotics. Use with caution in patients with risk factors for stroke.

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

    There has been found to be a risk of QT interval prolongation in patients receiving an antipsychotic medication. Persistently prolonged QT intervals may increase the risk of malignant arrhythmias. For this reason patients who are susceptible to arrhythmias (e.g. hypokalaemia, hypomagnesaemia or a genetic predisposition) should be treated with caution. Caution should also be exercised in patients with a history of cardiovascular disease, e.g. QT interval prolongation, significant bradycardia (<50 beats per minute), a recent acute myocardial infarction, uncompensated heart failure, or cardiac arrhythmias.

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

    Only recommended for short term use, duration of treatment should not exceed 2 weeks.

    Withdrawal should be gradual, as abrupt cessation produce withdrawal symptoms ( see Withdrawal Symptoms ) .

    Consider reduction in dose or discontinuation of zuclopenthixol if tardive dyskinesia develops.

    Discontinue if the patient develops neuroleptic malignant syndrome and administer symptomatic and supportive treatment.
    Symptoms may persist for more than a week after discontinuation of oral neuroleptics.

    Perform blood counts if signs of persistent infection develop, as cases of blood dyscrasias have been reported.

    Use with caution in diabetic patients as zuclopenthixol like other psychotropics may modify insulin and glucose responses.

    Women of child bearing age must use effective contraception throughout treatment and for some time afterwards.

    Patients should be warned that their ability to drive and operate machines may be impaired.

    Use in Porphyria

    The Norwegian Porphyria Centre (napos) lists zuclopenthixol as 'possibly porphyrogenic' in the Drug Database for Acute Porphyria although another source lists it as contraindicated.

    Pregnancy and Lactation


    Zuclopenthixol is contraindicated in pregnancy. At the time of writing, there are no published animal or human studies concerning exposed pregnancies and their outcomes.

    'There is some indication of an overall increased risk of malformations associated with the use of antipsychotics (2.4%, that is 24 per 1,000), although it is not clear if this may relate to the underlying illness (information on individual drugs is very limited).' (National Institute of Health and Clinical Excellence, CG045, 2007)

    Psychosis in pregnancy should be treated, as there is a risk if the psychosis is left untreated. There is also a risk to the mother and foetus from abrupt withdrawal of an antipsychotic. Pharmacological treatment should be with the lowest effective dose for the shortest time.

    Deep intramuscular (Depot) injections of antipsychotics should not be used in the mother, as the newborn infant may show extrapyramidal symptoms several months after administration. The extrapyramidal symptoms are usually self limiting.

    Regular psychiatric and obstetric care is recommended for the early diagnosis of relapse or pregnancy complications (i.e. intrauterine growth retardation, premature contractions).

    The newborn of mothers treated with antipsychotics up to, or during labour, may show signs of intoxication such as lethargy, tremor and hyperexcitability, and have low apgar scores. Neonate exposed to antipsychotics during the third trimester are at risk of extrapyramidal and/or withdrawal symptoms that may vary in severity and duration following delivery. Neonates should be monitored carefully.

    Schaefer, Peters & Miller (2007) recommend that the newborn infants be observed for adaption disorders, extrapyramidal, and withdrawal symptoms for at least 2 days, if an antipsychotic has been used up to delivery. For the prevention of adaption disorders a reduction in dose, or dose interruption in the days before delivery can be discussed with the patient if the clinical course allows. The dose before delivery should be restored immediately after delivery to prevent a relapse.

    The National Institute for Health and Clinical Excellence (NICE) have published guidance for the treatment of mental health patients throughout the antenatal and postnatal period. The guidance can be accessed at

    Women of child bearing age should be informed about the risks of psychotropic medication on any future pregnancy and the risks of untreated illness, together with the appropriate information about contraception.

    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 14-17 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 at

    Licensed in pregnancy? - No

    Recommended for use in pregnancy? - No

    Known human teratogen? - Unknown.


    Zuclopenthixol is contraindicated while breastfeeding. Zuclopenthixol is excreted into breast milk. At the time of writing, there are no published studies concerning the use of zuclopenthixol while breastfeeding.

    Schaefer, Peters & Miller (2007) and Briggs, Freeman & Yaffe (2008) list some experience from infants whose mothers received zuclopenthixol while breastfeeding. This experience suggests that zuclopenthixol is excreted into breast milk in small quantities. None of the infants experienced and adverse effects.

    However, this is only very limited data and caution is still advised when using zuclopenthixol in a nursing mother.

    Deep intramuscular (Depot) injections of antipsychotics should not be used in the mother, as the infant may show extrapyramidal symptoms several months after administration. The extrapyramidal symptoms are usually self limiting.

    The National Institute for Health and Clinical Excellence (NICE) have published guidance for the treatment of mental health patients throughout the antenatal and postnatal period. The guidance can be accessed at

    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

    Drug excreted in breast milk? - Yes

    Considered suitable or recommended by manufacturer? - No

    UK Drugs in Lactation Advisory Service Classification - Minor adverse effects may be anticipated on theoretical grounds. This drug should only be administered where both the mother and infant can be monitored.

    Drug substance licensed in infants? - No

    Drug known to affect lactation? - Unknown


    Patients should be advised that zuclopenthixol may impair their ability to drive and operate machinery due to its sedative effect, especially at the start of treatment and following alcohol consumption. Patients should be advised not to drive if they experience blurred vision.

    Advise women of child bearing age that they must use effective contraception throughout treatment and for some time afterwards.

    Side Effects

    Prolongation of QT interval
    Attention disturbances
    Gait abnormality
    Tardive dyskinesia
    Speech disturbances
    Neuroleptic malignant syndrome
    Disturbances in accommodation
    Abnormal vision
    Oculogyric crisis
    Nasal congestion
    Dry mouth
    Abdominal pain
    Micturition disorders
    Urinary retention
    Muscle rigidity
    Disturbances of appetite
    Weight changes
    Decreased glucose tolerance
    Hot flushes
    Anaphylactic reaction
    Altered liver function tests
    Cholestatic hepatitis
    Failure of ejaculation
    Erectile dysfunction
    Orgasmic dysfunction
    Vulvovaginal disorders
    Dream abnormalities
    Reduced libido
    Increased libido
    Sudden unexplained death
    Pigmentation disorder
    Withdrawal syndrome (neonatal)

    Withdrawal Symptoms and Signs

    Abrupt discontinuation may result in withdrawal symptoms including the following:
    Alternate feelings of warmth and cold

    Symptoms generally begin with 1 to 4 days of withdrawal and abate within 7 to 14 days.


    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 ( ).

    Shelf Life and Storage

    Store at or below 25 degrees C
    Protect from light

    Reference Sources

    Summary of Product Characteristics: Clopixol Acuphase injection. Lundbeck Ltd. Revised January 2012

    British National Formulary, 63rd Edition (2012) Pharmaceutical Press, London.

    Drugs in Pregnancy and Lactation: A Reference Guide for Fetal and Neonatal Risk, 8th Edition. ed. Briggs, Freeman & Yaffe; Lippincott Williams & Wilkins, Philadelphia 2008

    Drugs during Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd Edition, ed. Schaefer, Peters & Miller, Academic Press, London 2007

    Therapeutics in Pregnancy and Lactation. ed. Lee, Inch & Finnigan; Radcliffe Medical Press, Kent 2000

    The Renal Drug Handbook, 3rd Edition, ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon 2009

    UK Drugs in Lactation Advisory Service, Antipsychotics, UKMiCentral Medicines Information NHS, November 2004
    Available at
    Accessed Nov 26, 2010

    Antenatal and postnatal mental health; The NICE guideline on clinical management and service guidance, National Institute for Healthcare and Clinical Excellence, 2007.
    Available at
    Accessed Nov 26, 2010

    Drugs in acute porphyria
    available at
    Last accessed: 17th December 2010

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