Typical Antipsychotic (Thioxanthene) — Oral and Depot Formulations Pregnancy: §4.6: zuclopenthixol should not be administered during pregnancy unless the expected benefit to the patient outweighs the theoretical risk to the foetus. Neonates exposed to antipsychotics during the third trimester are at risk of adverse reactions including extrapyramidal and/or withdrawal symptoms varying in severity and duration after delivery (agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, feeding disorder) — newborns should be monitored carefully. Animal studies have shown reproductive toxicity. Breast-feeding: zuclopenthixol is found in breast milk in low concentrations and is not likely to affect the infant at therapeutic doses (the dose ingested by the infant is less than 1% of the weight-related maternal dose in mg/kg) — breast-feeding can be continued if considered of clinical importance, but observation of the infant is recommended, particularly in the first 4 weeks after birth.

Zuclopenthixol

Brand names: Clopixol (oral/depot), Acuphase (short-acting IM — 72h)

Zuclopenthixol is a first-generation (typical) antipsychotic of the thioxanthene class used in the management of schizophrenia and other psychoses.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Dosage range 4-150 mg/day in divided doses; usual initial dose 20-30 mg/day, usual maintenance dose 20-50 mg/day

Route: Oral

Frequency: In divided doses (tablets swallowed with water)

Max: 150 mg/day; maximum dosage per single dose is 40 mg

Source: UK SPC (eMC) for Clopixol 10 mg film-coated tablets, §4.2 (https://www.medicines.org.uk/emc/product/11789/smpc) — this is the ORAL TABLET SPC. Depot/intramuscular preparations (zuclopenthixol decanoate, zuclopenthixol acetate) have separate SPCs and different regimens, which were NOT retrieved in this bundle; do not apply these oral figures to injectable use. ADULTS: the dosage range is 4-150 mg/day in divided doses; the usual initial dose is 20-30 mg/day (sometimes with higher dosage requirements in acute cases), increasing as necessary; the usual maintenance dose is 20-50 mg/day; maximum dosage per single dose is 40 mg. TRANSFER TO DEPOT: when transferring patients from oral to depot antipsychotic treatment, the oral medication should not be discontinued immediately but gradually withdrawn over a period of several days after administering the first injection. OLDER PATIENTS: in accordance with standard medical practice, initial dosage may need to be reduced to a quarter or half the normal starting dose in the frail or older patient. HEPATIC IMPAIRMENT: use with caution in patients with liver disease; patients with compromised hepatic function should receive HALF the recommended dosages, and serum-level monitoring is advised. PAEDIATRIC (not expressed as a per-kg dose in the SPC): Clopixol is NOT indicated for use in children due to lack of clinical experience. Verify any under-18 use against a children's formulary. QT PROLONGATION (§4.4): as with other antipsychotics, zuclopenthixol may cause QT prolongation. METHOD OF ADMINISTRATION: the tablets are swallowed with water. §4.5 Interactions was not retrieved in this bundle — the interactions listed below are taken from the §4.3 Contraindications and §4.4 Warnings text; verify the full §4.5.

Dose adjustments

Renal

Zuclopenthixol can be given in usual doses to patients with reduced renal function. Where there is renal failure, dosage should be reduced to half the normal dosage.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Circulatory collapse
Depressed level of consciousness due to any cause (e.g. intoxication with alcohol, barbiturates or opiates)
Coma

Side effects

Very common: somnolence, akathisia, hyperkinesia, hypokinesia, extrapyramidal symptoms; common tremor, dystonia, hypertonia, dizziness, headache, paraesthesia, disturbance in attention; uncommon tardive dyskinesia, parkinsonism, syncope, convulsion; very rare neuroleptic malignant syndrome
Very common: dry mouth; common salivary hypersecretion, constipation, vomiting, dyspepsia, diarrhoea; uncommon abdominal pain, nausea
Common: increased appetite and weight increased; uncommon decreased appetite and weight decreased; rare hyperglycaemia, impaired glucose tolerance, hyperlipidaemia
Common: tachycardia, palpitations; rare ECG QT prolonged; uncommon hypotension and hot flush; very rare venous thromboembolism
Common: insomnia, depression, anxiety, nervousness, abnormal dreams, agitation, decreased libido; common accommodation disorder and abnormal vision, vertigo, hyperhidrosis, pruritus, myalgia, micturition disorder/urinary retention/polyuria; rare hyperprolactinaemia, gynaecomastia, galactorrhoea, amenorrhoea, priapism, thrombocytopenia, neutropenia, leukopenia, agranulocytosis

Interactions

CNS depressants — alcohol, barbiturates and opiates: zuclopenthixol is contraindicated where these have caused a depressed level of consciousness
Other medicines that prolong the QT interval — as with other antipsychotics, zuclopenthixol may cause QT prolongation (§4.4; the full §4.5 interactions section was not retrieved in this bundle)

Clinical monograph

How it works

It acts principally by antagonising dopamine D2 receptors in the central nervous system.

Prescribing in practice

Distinguish carefully between the short-acting acetate (acuphase) and the longer-acting decanoate depot formulations, as confusing them risks serious over- or under-treatment.
Extrapyramidal side effects are common and the drug shares the class risk of tardive dyskinesia and neuroleptic malignant syndrome.
Use with caution in cardiac disease and where there are QT or other antipsychotic-related risks.

Monitoring

Monitor for extrapyramidal effects, sedation, and the metabolic and cardiac parameters expected with antipsychotic therapy.

Counselling the patient

Report any muscle stiffness, tremor or abnormal movements promptly.
Seek urgent help for high fever, sweating or marked confusion.
Attend appointments for depot injections and monitoring as arranged.

Evidence & guidelines

First-generation antipsychotics remain established treatments for psychosis, with monitoring guided by NICE and SPC recommendations.

Reference: NICE CG178 (Psychosis and Schizophrenia); NICE NG10 (Violence and Aggression); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways