Prochlorperazine

Pronunciation: proh-klor-PER-a-zeen.

Generic name
prochlorperazine
Drug class
Phenothiazine antipsychotic / antiemetic
Form
Tablet (5 mg or 10 mg), buccal tablet, suppository, or injection, depending on market
Route
Oral, buccal, rectal, or injection depending on formulation and country
Legal status
Prescription-only

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Stemetil / Stemzine (plus generics) (5) · Full directory

What prochlorperazine is and how it works

Prochlorperazine is a prescription-only phenothiazine medicine used mainly to control severe nausea and vomiting, and also, in some situations, to treat schizophrenia or as a short-term add-on for anxiety. It is one of the older antipsychotic/antiemetic medicines, in use since the 1950s-60s. (1)

Take prochlorperazine exactly as your prescriber directs. Your dose depends on why it is being used, your age, and how you respond -- there is no single standard dose for everyone.

Mechanism of action: how prochlorperazine works

Prochlorperazine is a piperazine-derivative phenothiazine with dopamine (D2) receptor antagonist activity, giving it both antipsychotic and antiemetic effects, with less sedation than chlorpromazine. (1)

What prochlorperazine is used for

Severe nausea and vomiting

Used to control severe nausea and vomiting from various causes, including migraine. (1)

Schizophrenia and certain psychotic conditions

Used in the management of schizophrenia and, in some countries, acute mania. (1)

Short-term anxiety (limited use)

Sometimes used short-term as an add-on for non-psychotic anxiety, but it is not usually a first-choice treatment for this, and use is generally limited to no more than 12 weeks. (1)

Vertigo (Meniere's disease and labyrinthitis)

Used in some countries for vertigo caused by Meniere's disease, labyrinthitis, or other causes. (2) (6)

Before taking prochlorperazine

Do not take / not appropriate for

  • Do not use prochlorperazine to treat behavioral problems in older adults with dementia-related psychosis -- it is not approved for this and carries a boxed warning of increased risk of death in this group. (all countries) (1)
  • Do not use prochlorperazine if you are in a coma or have taken large amounts of other sedating (CNS depressant) medicines. (United States) (1)
  • Do not give prochlorperazine to young children under the specified age/weight limits for your country, or use it before pediatric surgery. (United States) (1)

Tell your clinician about

  • Any personal or family history of Parkinson's disease or other movement disorders.
  • Any history of seizures, since phenothiazines can lower the seizure threshold.
  • Any heart rhythm problems or family history of QT prolongation.
  • Any history of low blood pressure, falls, or bone fractures.
  • All other medicines you take, especially other sedating medicines, blood pressure medicines, anticonvulsants, or blood thinners.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • If you are elderly, or caring for someone who is, given the boxed warning about dementia-related psychosis.
(1)

How to take prochlorperazine

  • Take exactly as prescribed; your prescriber will choose the lowest effective dose for your situation and adjust as needed.
  • Older adults and children are usually started on lower doses and monitored more closely, because they are more sensitive to side effects.
  • Any change to your dose or treatment plan should be made together with your prescriber.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

If you miss a dose, take it as soon as you remember unless it is close to your next scheduled dose, in which case skip the missed dose. Do not take two doses together. Contact your prescriber if you are unsure.

Overdose

Seek urgent medical attention if too much prochlorperazine has been taken, especially with symptoms such as severe drowsiness, muscle stiffness, an irregular heartbeat, or loss of consciousness. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Drowsiness and dizziness.

What to notice: Drowsiness and dizziness.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Blurred vision.

What to notice: Blurred vision.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Low blood pressure, especially on standing up.

What to notice: Low blood pressure, especially on standing up.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Skin reactions.

What to notice: Skin reactions.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Missed periods (amenorrhoea).

What to notice: Missed periods (amenorrhoea).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Increased risk of death in elderly patients with dementia-related psychosis — boxed_warning

Symptoms: Not applicable -- this is a population-level risk rather than a symptom to watch for.

Action: This medicine is not approved for behavioral problems related to dementia in older adults; discuss any such use with a prescriber, who will weigh this real, increased mortality risk. (1)

Signs of neuroleptic malignant syndrome (NMS) — emergency

Symptoms: High fever, severe muscle stiffness, confusion or altered mental state, irregular pulse or blood pressure, fast heartbeat, and sweating.

Action: Seek emergency medical help immediately -- this is a rare but potentially fatal reaction requiring urgent hospital care and stopping the medicine under clinician direction. (1)

Signs of tardive dyskinesia or other movement disorders (extrapyramidal symptoms) — high caution

Symptoms: Uncontrollable, repetitive movements of the face, tongue, or body (tardive dyskinesia, which can become permanent); muscle spasms of the neck/throat, tremor, shuffling walk, mask-like face, or restlessness.

Action: Tell your prescriber promptly -- these movement problems, particularly tardive dyskinesia, can become permanent if not addressed early, and a clinician will decide on the best course of action. (1)

Signs of an abnormal heart rhythm (QT prolongation) — high caution

Symptoms: Palpitations, dizziness, or fainting.

Action: Seek prompt medical attention -- phenothiazines can affect heart rhythm, especially when combined with certain other medicines. (2) (6)

Falls, especially in older adults — high caution

Symptoms: Dizziness, unsteadiness, or fainting on standing, which can lead to falls and fractures.

Action: Take extra care when standing up, and tell your prescriber if you feel unsteady. (1)

Interactions

  • Alcohol and other sedating (CNS depressant) medicines, including some anaesthetics and strong painkillers, can add to prochlorperazine's sedative effect. (1)
  • Thiazide 'water tablets' (diuretics) may worsen dizziness on standing. (1)
  • Beta-blockers such as propranolol can raise blood levels of both medicines when combined. (1)
  • Adrenaline (epinephrine) should generally be avoided, as phenothiazines can reverse its usual blood-pressure-raising effect. (1)
  • Phenytoin (an anticonvulsant) levels may be affected, increasing the risk of phenytoin toxicity. (1)
  • May reduce the effect of blood-thinning medicines (oral anticoagulants). (1)
  • Other medicines that affect heart rhythm (QT-prolonging medicines) may increase the risk of a serious abnormal heart rhythm. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Safety in pregnancy has not been established. It is generally used only when nausea and vomiting are so severe that treatment is needed and the benefit is thought to outweigh the risk. Exposure late in pregnancy may cause movement or withdrawal symptoms in the newborn. Discuss with your prescriber. (1) (2) (3) (4) (5) (6)

Breastfeeding

Phenothiazines pass into breast milk; caution is advised. Discuss the benefits and risks with your prescriber. (1) (2) (3) (4) (5) (6)

Children

Doses are individually adjusted, since children are more prone to movement-related (extrapyramidal) side effects; not used in very young children/those under specific age or weight limits, and not before pediatric surgery. (1) (2) (3) (4) (5) (6)

Elderly

Used with extra caution and lower doses -- older adults have a higher risk of movement disorders, low blood pressure, falls, and (for use in dementia-related psychosis specifically) a boxed-warning mortality risk. (1) (2) (3) (4) (5) (6)

Hepatic_impairment

Not specifically detailed in the source reviewed for this dossier -- tell your prescriber about any liver problems. (1) (2) (3) (4) (5) (6)

Renal_impairment

Not specifically detailed in the source reviewed for this dossier -- tell your prescriber about any kidney problems. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Screening for Parkinson's disease or other movement disorders
  • Cardiac history and other QT-prolonging medicines
  • Review of other sedating medicines

During treatment

  • Watching for early movement-disorder symptoms (such as fine tongue movements), which can signal early tardive dyskinesia.
  • Blood pressure, especially on standing, particularly in older adults.
  • Signs of infection, fever, or muscle stiffness that could indicate neuroleptic malignant syndrome.
  • Heart rhythm if other QT-prolonging medicines are also used.
(1)

Storage

Store at 20-25°C (68-77°F). Protect from light. Keep in a tightly closed, light-resistant container.

Study the drug class: Typical antipsychotics

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information; verify against the current full label before prescribing.

United States

Indication: Severe nausea/vomiting; schizophrenia; short-term non-psychotic anxiety (adjunct, limited use)

Dose summary: Nausea/vomiting: 5-10 mg 3-4 times daily, individualised; doses above 40 mg/day only in resistant cases. Psychiatric use: 5-10 mg 3-4 times daily, up to 100-150 mg/day in severe cases. Anxiety: not more than 20 mg/day or 12 weeks. Begin with the lowest recommended dose; elderly and pediatric patients need lower doses with gradual titration.

Renal context: Not established in the source reviewed for this dossier. (1)

Mechanism of action

Hepatic guidance

Not specifically detailed in the source reviewed for this dossier; monitor as clinically indicated.

Overdose note

Manage overdose with supportive care, monitoring for CNS and cardiac (QT-related) effects, and treatment of any extrapyramidal reactions; no specific antidote is described in the source reviewed. (1)

Frequently asked questions

Is prochlorperazine available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, it is approved in all of these regions (as Compazine/generic prochlorperazine in the US, and mostly as Stemetil or Stemzine elsewhere), though within the EU it is authorised in some member states, such as Ireland, but not in every one (for example, not currently in Germany or Austria). (1) (2) (3) (4) (5) (6)

Is prochlorperazine safe for elderly people with dementia?

No -- it carries a boxed warning that elderly patients with dementia-related psychosis have an increased risk of death when treated with antipsychotic medicines like this one, and it is not approved for that use. (1)

Can prochlorperazine cause permanent movement problems?

It can, though this is uncommon with short courses. Tardive dyskinesia -- involuntary, repetitive movements, often of the face or tongue -- can develop with longer use and higher cumulative doses, and can be permanent even after stopping treatment. Tell your prescriber promptly about any unusual movements. (1)

What is the mechanism of action of prochlorperazine?

Prochlorperazine is a piperazine-derivative phenothiazine with dopamine (D2) receptor antagonist activity, giving it both antipsychotic and antiemetic effects, with less sedation than chlorpromazine. (1)

What is the generic name of Prochlorperazine?

The generic name is prochlorperazine. (1)

What class of drug is prochlorperazine?

Prochlorperazine is classed as: Phenothiazine antipsychotic / antiemetic. (1)

References

  1. PROCHLORPERAZINE MALEATE Tablets, USP -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · accessed 2026-07-29 · source 1
  2. Stemetil 5 mg Tablet / Stemetil 12.5 mg/1 ml Solution for injection -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Atnahs Pharma UK Ltd · United Kingdom · accessed 2026-07-29 · source 2
  3. Stemetil 5mg Tablets -- HPRA authorised medicine entryHealth Products Regulatory Authority (HPRA), Ireland · European Union (Ireland, as confirmed representative EU member state) · accessed 2026-07-29 · source 3
  4. STEMETIL (prochlorperazine mesylate injection / suppositories) Product MonographHealth Canada product monograph, sanofi-aventis Canada Inc. · Canada · accessed 2026-07-29 · source 4
  5. STEMETIL prochlorperazine maleate 5mg tablet / mesilate injection -- ARTG registrationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 5
  6. Stemetil New Zealand Data SheetMedsafe (New Zealand regulator) · New Zealand · accessed 2026-07-29 · source 6

Brand names by country

Single-ingredient prochlorperazine names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Compro25 mg · padagis us llc

United Kingdom

  • Stemetil (2)MHRA licensed emc smpc confirmed · 5 mg tablet, 12.5 mg/mL injection, 3 mg buccal · Atnahs Pharma UK Ltd

Canada

  • PROCHLORAZINE
  • PROCHLORPERAZINE MESYLATE INJ
  • PMS-PROCHLORPERAZINE SUPPOSITOIRES
  • PMS PROCHLORPERAZINE INJ

Australia

  • Stemetil / Stemzine (plus generics) (5)TGA ARTG registered 1991-10-21 confirmed · 5 mg tablet, 12.5 mg/mL injection · Atnahs Pharma Australia Pty Ltd

New Zealand

  • Stemetil (6)Medsafe approved confirmed · 5 mg tablet, 12.5 mg injection, 25 mg suppository · multiple registered suppliers
View brands in additional countries.

European Union

Stemetil (3)

This page provides general reference information about prochlorperazine and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions should be made with your prescriber.

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