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Typical (First-generation) Antipsychotic — Low-potency

Chlorpromazine

Brand names: Largactil

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

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, anxiety and agitation — §4.2 verbatim: 'Initially 25 mg t.d.s. or 75 mg at bedtime increasing by daily amounts of 25 mg to an effective maintenance dose. This is usually in the range 75 to 300 mg daily but some patients may require up to 1 g daily.'
Route: Oral (chlorpromazine 100 mg tablets; SPC 'Method of administration: Oral'). SCOPE: intramuscular dosing, which this page also lists for acute agitation, is not covered by the fetched source.
Frequency: Three times daily, or as a single 75 mg bedtime dose, increased by 25 mg daily increments to an effective maintenance dose.
Max: Maximum 1 g daily — §4.2: the adult range is 'usually in the range 75 to 300 mg daily but some patients may require up to 1 g daily'. No higher adult figure appears anywhere in the fetched UK SPC.
TITRATION (§4.2, verbatim): 'Dosages should be low to begin with and gradually increased under close supervision until the optimum dosage for the individual is reached. Individuals vary considerably and the optimum dose may be affected by the formulation used.' ELDERLY OR DEBILITATED (§4.2): 'Start with 1/3-1/2 usual adult dose with a more gradual increase in dosage.' OTHER ADULT INDICATIONS IN THE SAME SPC — hiccups: '25-50 mg t.d.s. or q.d.s.'; nausea and vomiting of terminal illness: '10-25 mg every 4-6 hours' (elderly or debilitated: initially 1/3-1/2 adult dose). WITHDRAWAL (§4.4): withdrawal symptoms including nausea, vomiting and insomnia have very rarely been reported after abrupt cessation of high doses, 'Therefore, gradual withdrawal is advisable'; and 'In schizophrenia, the response to neuroleptic treatment may be delayed. If treatment is withdrawn, the recurrence of symptoms may not become apparent for some time.' US LABELLING — CROSS-REFERENCE ONLY, DO NOT SUBSTITUTE FOR THE UK SPC: it quotes different figures for its own studied populations (outpatients '10 mg t.i.d. or q.i.d., or 25 mg b.i.d. or t.i.d.'; less acutely disturbed '25 mg t.i.d. Increase gradually until effective dose is reached – usually 400 mg daily'; hospitalised acute schizophrenic or manic states '500 mg a day is generally sufficient... there is usually little therapeutic gain to be achieved by exceeding 1,000 mg a day for extended periods'). SOURCE LIMITS: UK §4.4 was truncated mid-sentence, §4.5 was not retrieved (so no UK interaction section is available) and the §4.8 table was truncated.

Paediatric dose

Route: Oral
Frequency: Every 4-6 hours in the 1-5 years band; the 6-12 years band is expressed as a fraction of the adult dose, not as a per-kg dose
Max: Maximum 40 mg daily in children 1-5 years; maximum 75 mg daily in children 6-12 years — §4.2 'maximum recommended dose' for schizophrenia, other psychoses, anxiety and agitation.
dosePerKg is deliberately null: the SPC regimen is AGE-BANDED and only the 1-5 years band is expressed per kg, so no single per-kg figure is valid across the paediatric range and none should be fed to the weight calculator. §4.2 verbatim (schizophrenia, other psychoses, anxiety and agitation): 'Children under 1 year: Do not use unless the risk-benefit ratio has been assessed. Children 1-5 years: 0.5 mg/kg body weight every 4-6 hours to a maximum recommended dose of 40 mg daily. Children 6-12 years: 1/3-1/2 adult dose to a maximum recommended dose of 75 mg daily.' For nausea and vomiting of terminal illness the SPC gives: 'Children 1-5 years: 0.5 mg/kg every 4-6 hours. Maximum daily dosage should not exceed 40 mg. Children 6-12 years: 0.5 mg/kg every 4-6 hours. Maximum daily dosage should not exceed 75 mg.' For hiccups it states 'No information available' for every paediatric band. §4.8 notes that acute dystonias or dyskinesias are 'more common in children and young adults and usually occur within the first 4 days of treatment or after dosage increases'. Verify the paediatric dose against a children's formulary and seek specialist paediatric input.

Dose adjustments

Renal

Not stated — no renal-impairment dosing statement appears in any fetched section of the UK SPC (§4.2, §4.3, §4.4 [truncated], §4.6, §4.8) or in the fetched US label sections.

Hepatic

No dose adjustment is given in the fetched UK SPC sections. US label (ADVERSE REACTIONS, jaundice): 'There is no conclusive evidence that pre-existing liver disease makes patients more susceptible to jaundice. Alcoholics with cirrhosis have been successfully treated with chlorpromazine hydrochloride without complications. Nevertheless, the medication should be used cautiously in patients with liver disease.'

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.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION Adults Adjust dosage to individual and the severity of his condition, recognizing that the milligram for milligram potency relationship among all dosage forms has not been precisely established clinically. It is important to increase dosage until symptoms are controlled. Dosage should be increased more gradually in debilitated or emaciated patients. In continued therapy, gradually reduce dosage to the lowest effective maintenance level, after symptoms have been controlled for a reasonable period. Elderly Patients In general, dosages in the lower range are sufficient for most elderly patients. Since theyappear to be more susceptible to hypotension and neuromuscular …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-10-16. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

  • Hypersensitivity to chlorpromazine or to any of the excipients listed in section 6.1 (UK §4.3)
  • Hypothyroidism (UK §4.3)
  • Bone marrow depression (UK §4.3)
  • Phaeochromocytoma (UK §4.3)
  • Myasthenia gravis (UK §4.3)
  • Risk of angle-closure glaucoma (UK §4.3)
  • Risk of urinary retention related to urethroprostatic disorders (UK §4.3)
  • History of agranulocytosis (UK §4.3)
  • Dopaminergic antiparkinsonism agents (UK §4.3)
  • Nursing mothers (UK §4.3, cross-referring to §4.6)
  • Citalopram, escitalopram (UK §4.3)
  • Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption — excipient contraindication for this tablet (UK §4.3)
  • US label adds: 'Do not use in comatose states or in the presence of large amounts of central nervous system depressants (alcohol, barbiturates, narcotics, etc.)'

Side effects

  • Nervous system: sedation and somnolence; dyskinesia (acute dystonias or dyskinesias, usually transitory, 'more common in children and young adults'); tardive dyskinesia; extrapyramidal disorder; akathisia 'often after large initial dose'; hypertonia, convulsion, torticollis, oculogyric crisis, trismus, akinesia, hyperkinesia; parkinsonism, 'more common in adults and the elderly. It usually develops after weeks or months of treatment' (§4.8)
  • Neuroleptic malignant syndrome — hyperthermia, rigidity, autonomic dysfunction and altered consciousness (§4.8; §4.4 requires treatment interruption for unexplained hyperpyrexia)
  • Cardiac: ECG changes including QT prolongation, ST depression, U-wave and T-wave changes; ventricular arrhythmia, A-V block, ventricular fibrillation, ventricular tachycardia, torsade de pointes; cardiac arrest and sudden death/sudden cardiac death reported during neuroleptic phenothiazine therapy (§4.8)
  • Vascular: orthostatic hypotension — 'Elderly or volume depleted subjects are particularly susceptible: it is more likely to occur after intramuscular administration'; venous embolism, pulmonary embolism (sometimes fatal), deep vein thrombosis (§4.8)
  • Blood and lymphatic: agranulocytosis, leukopenia, eosinophilia, thrombocytopenia (§4.8)
  • Endocrine: hyperprolactinaemia, amenorrhoea, galactorrhoea, gynaecomastia, erectile dysfunction, impotence, female sexual arousal disorder (§4.8)
  • Metabolism: weight increased, impaired glucose tolerance, hyperglycaemia, hypertriglyceridaemia, hyponatraemia, inappropriate antidiuretic hormone secretion (§4.8)
  • Immune: systemic lupus erythematosus, antinuclear antibody positive, bronchospasm, anaphylactic reactions (§4.8)
  • Gastrointestinal and anticholinergic: dry mouth, constipation, ischaemic colitis, ileus; accommodation disorder and eye deposits/ocular changes (§4.8)
  • Respiratory depression and nasal stuffiness; psychiatric anxiety, lethargy, altered mood (§4.8)
  • Jaundice (US label): 'Most cases occur between the second and fourth weeks of therapy. The clinical picture resembles infectious hepatitis, with laboratory features of obstructive jaundice... It is usually promptly reversible on withdrawal of the medication; however, chronic jaundice has been reported.'
  • NOTE: the UK §4.8 table was truncated at the source-fetch limit, so this is not the complete adverse-reaction table

Monitoring

  • Full blood count — §4.4: 'As agranulocytosis has been reported, regular monitoring of the complete blood count is recommended. The occurrence of unexplained infections or fever may be evidence of blood dyscrasia and requires immediate haematological investigation'
  • Patient counselling — §4.4: 'All patients must be advised that, if they experience fever, sore throat or any other infection, they should inform their physician immediately and undergo a complete blood count'
  • Neuroleptic malignant syndrome — §4.4: 'treatment must be interrupted in the event of unexplained hyperpyrexia since this can be one of the signs of neuroleptic malignant syndrome (pallor, hyperthermia, disorders of autonomic function, altered consciousness, muscle rigidity)'; hyperhidrosis and irregular blood pressure can precede hyperthermia
  • QT risk factors before starting and as needed during treatment — §4.4 lists bradycardia less than 55 beats per minute, hypokalaemia, hypocalcaemia, hypomagnesaemia, starvation, alcohol abuse, concomitant QT-prolonging therapy and congenital long QT interval: 'medical and laboratory evaluations should be performed to rule out possible risk factors before initiating treatment with a neuroleptic agent and as deemed necessary during treatment'
  • Withdraw gradually and watch for delayed relapse after withdrawal (§4.4)
  • No monitoring interval beyond the above is specified in the fetched sections (§4.4 was truncated at the fetch limit)

Clinical monograph

How it works

It blocks dopamine D2 receptors in the mesolimbic pathway, accounting for its antipsychotic effect, and also antagonises histaminergic, cholinergic and alpha-adrenergic receptors, which underlies its sedative, anticholinergic and hypotensive effects.

Prescribing in practice

  • Like all antipsychotics, it increases the risk of stroke and death in elderly patients with dementia and should generally be avoided in this group.
  • It is markedly sedating and can cause extrapyramidal effects, postural hypotension, QT-interval prolongation and a lowered seizure threshold — use with caution in epilepsy and in patients at cardiac risk.
  • It causes photosensitivity reactions; advise sun protection and consult the SPC for guidance on cardiometabolic and other monitoring.

Monitoring

Monitor for extrapyramidal symptoms, sedation and postural blood pressure. Baseline and periodic ECG and electrolytes are advisable given the QT risk, alongside weight, glucose and lipids in line with antipsychotic monitoring. Remain alert for neuroleptic malignant syndrome.

Counselling the patient

  • Protect your skin from strong sunlight by covering up and using a high-factor sunscreen, as this medicine can make you burn more easily.
  • Stand up slowly to reduce dizziness, and avoid alcohol, which adds to drowsiness.
  • Report any uncontrolled movements, muscle stiffness, fever or a fast or irregular heartbeat.

Evidence & guidelines

A long-established typical antipsychotic; UK guidance (NICE) and MHRA advice highlight the increased stroke and mortality risk when antipsychotics are used in elderly people with dementia.

Reference: NICE CG178 (Psychosis and Schizophrenia); 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).

Related

Curated clinical cross-links plus same-class fallbacks.

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