Typical (low-potency) antipsychotic Pregnancy: There is inadequate evidence of safety in human pregnancy and there is evidence of harmful effects in animals; avoid in pregnancy unless the physician considers it essential. It may occasionally prolong labour and should then be withheld until the cervix is dilated 3–4 cm. Neonates exposed during the third trimester are at risk of extrapyramidal and/or withdrawal symptoms and must be monitored carefully. Chlorpromazine should not be used during lactation (phenothiazines are excreted in breast milk, with potential for drowsiness and increased risk of tardive dyskinesia in the infant); nursing mothers are listed as a contraindication in §4.3.

Chlorpromazine hydrochloride

Brand names: Largactil

Chlorpromazine is a first-generation (typical) antipsychotic used for schizophrenia and other psychoses and for the short-term management of severe psychomotor agitation.

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: Schizophrenia, other psychoses, mania, hypomania, anxiety, psychomotor agitation, excitement, violent or dangerously impulsive behaviour: initially 25 mg three times daily, or 75 mg at bedtime, increasing daily by 25 mg to an effective maintenance dose. The maintenance dose is usually 70 to 300 mg daily.

Route: Oral (the fetched SPC is Chlorpromazine Hydrochloride 100 mg/5 mL Oral Syrup — 'for oral administration only')

Frequency: Three times daily, or as a single dose at bedtime

Max: Maintenance may be up to 1 g daily in some patients

Source: eMC SPC for Chlorpromazine Hydrochloride 100 mg/5 mL Oral Syrup, §4.2. Dosage should be low to begin with and increased gradually under close supervision until the optimum dose within the recommended range is reached; individual response and dosage requirements may vary greatly. Other indications: INTRACTABLE HICCUP — adults 25 to 50 mg three or four times daily (children: not recommended / no information available). NAUSEA AND VOMITING OF TERMINAL ILLNESS — adults 10 to 25 mg every 4 to 6 hours. ELDERLY OR DEBILITATED patients: start with one-third to one-half of the usual adult dose, with a more gradual increase in dosage (for nausea and vomiting of terminal illness, initially one-third to one-half the adult dose, then clinical judgement to obtain control). ROUTE CAVEAT: this label covers the ORAL syrup only — parenteral (intramuscular) chlorpromazine dosing is NOT in this source and must be taken from the relevant injection SPC. eMC §4.5 was not captured in the fetched source and the US label carried no drug-interaction section, so no interactions list is recorded — the UK SPC §4.5 must be consulted (note §4.3 already bars dopaminergic antiparkinsonism agents, citalopram and escitalopram). Renal dosing: none stated in the fetched source.

Paediatric dose

Dose: 0.5 mg/kg

Route: Oral

Frequency: Every 4 to 6 hours

Max: 40 mg daily (children 1–5 years); 75 mg daily (children 6–12 years)

eMC §4.2 verbatim: psychoses/mania/agitation — 'Children under 1 year: Not recommended unless the need is life saving. Children 1–5 years: 0.5 mg/kg bodyweight every 4–6 hours to a maximum recommended dose of 40 mg daily. Children 6–12 years: 1/3 to 1/2 the adult dose up to a maximum recommended dose of 75 mg daily.' The 0.5 mg/kg figure recorded here is the 1–5 year regimen; the 6–12 year regimen is expressed as a fraction of the adult dose, NOT per kg. Nausea and vomiting of terminal illness — children under 1 year: do not use unless the need is life saving; children 1–5 years: 0.5 mg/kg every 4–6 hours, maximum daily dosage 40 mg; children 6–12 years: 0.5 mg/kg every 4–6 hours, maximum daily dosage 75 mg. Intractable hiccup: not recommended in children / no information available. Verify all under-18 dosing against a children's formulary before prescribing.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Paediatric weight-based calculator

Patient weight (kg)

Verify in a children's formulary

Contraindications

Hypersensitivity to chlorpromazine or to any of the excipients
Comatose states; severe CNS depression
History of blood dyscrasias including bone marrow depression and agranulocytosis
Severe cardiovascular disease
Risk of angle-closure glaucoma
Risk of urinary retention related to urethroprostatic disorders
Concomitant dopaminergic antiparkinsonism agents; concomitant citalopram or escitalopram
Nursing mothers

Side effects

Sedation and somnolence; dyskinesia (acute dystonias, usually transitory, more common in children and young adults, typically within the first 4 days or after dose increases), tardive dyskinesia, extrapyramidal disorder, akathisia, parkinsonism
Orthostatic hypotension (elderly or volume-depleted patients are particularly susceptible; more likely after intramuscular administration)
ECG changes including QT prolongation, ST depression and T-wave changes; cardiac arrhythmias including ventricular tachycardia, torsade de pointes and ventricular fibrillation; cardiac arrest and sudden death have been reported
Agranulocytosis, leucopenia, eosinophilia and thrombocytopenia — advise patients to report fever, sore throat or any infection immediately and to have a full blood count
Neuroleptic malignant syndrome (hyperthermia, rigidity, autonomic dysfunction and altered consciousness) — interrupt treatment in the event of unexplained hyperpyrexia
Anticholinergic effects — dry mouth, constipation, accommodation disorder; hyperprolactinaemia with amenorrhoea, galactorrhoea, gynaecomastia and erectile dysfunction; weight increase, impaired glucose tolerance and hyperglycaemia; venous thromboembolism including pulmonary embolism

Clinical monograph

How it works

It blocks dopamine D2 receptors (with additional antagonism at histaminergic, muscarinic and adrenergic receptors), reducing positive psychotic symptoms while accounting for its sedative and autonomic effects.

Prescribing in practice

It causes photosensitisation and contact sensitisation, so patients should avoid direct sunlight and those handling it should avoid skin contact, and it can also markedly lower the seizure threshold.
Like other antipsychotics it can prolong the QT interval and cause extrapyramidal effects, postural hypotension and, rarely, neuroleptic malignant syndrome.
Use with particular caution in the elderly, in whom antipsychotics increase the risk of stroke and death in dementia.

Monitoring

Monitor weight, metabolic parameters, blood pressure, ECG where indicated, and for extrapyramidal and sedative side-effects.

Counselling the patient

Protect your skin from strong sunlight and use a high-factor sunscreen.
Stand up slowly to avoid dizziness, especially when starting treatment.
Report any high fever with muscle stiffness urgently.

Evidence & guidelines

Chlorpromazine is an established antipsychotic; MHRA advice notes the increased risk of stroke and mortality with antipsychotics in elderly patients with dementia.

Reference: 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).

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