Chlorpromazine
1 medicine
Chlorpromazine is a first-generation antipsychotic that can rarely cause neuroleptic malignant syndrome, a life-threatening reaction with high fever, rigid muscles and confusion that needs emergency care.
Key facts
- Chlorpromazine is a first-generation antipsychotic that calms hallucinations, delusions and severe agitation, and is also used to control severe nausea, vomiting and persistent hiccups.
- It is taken by mouth or given by injection, once to several times a day; sedation can appear within an hour, while the effect on psychosis builds over days to weeks.
- Chlorpromazine can rarely trigger neuroleptic malignant syndrome, a life-threatening reaction with high fever, rigid muscles, confusion and an irregular heartbeat that needs emergency treatment.
- Seek urgent care for fever with stiff muscles, fainting, a fast or irregular heartbeat, or uncontrollable movements of the face or limbs.
What chlorpromazine treats
Chlorpromazine treats schizophrenia and other psychotic disorders, and manic episodes of bipolar disorder. It also controls severe nausea and vomiting, including before surgery, and persistent hiccups that have not responded to other measures. It is sometimes used short-term for severe agitation. It is not approved for treating behavioural symptoms of dementia in older adults.
How chlorpromazine works
Chlorpromazine blocks dopamine receptors in the brain, dampening the overactive dopamine signalling linked to hallucinations, delusions and agitation. It also blocks dopamine receptors in the brain's vomiting centre, which is why it controls nausea, and it blocks histamine and other receptors that contribute to its sedating, blood-pressure-lowering effect.
Before you take it
- Do not take chlorpromazine if you are in a comatose or severely sedated state, have bone marrow suppression, or have phaeochromocytoma.
- Tell your prescriber about Parkinson's disease, seizures, heart disease, or a prolonged QT interval, chlorpromazine can worsen movement symptoms and affect heart rhythm.
- It is not approved for older adults with dementia-related psychosis. It carries a higher risk of death in that group and should only be used for other approved reasons.
- Alcohol and other sedating medicines add to drowsiness and can slow breathing when combined with chlorpromazine.
Side effects
Common effects include drowsiness, dry mouth, blurred vision, constipation, low blood pressure on standing, weight gain, and increased sun sensitivity.
Stop and seek urgent medical care for any of these:
- Fever with stiff muscles and confusion.
- Fast or irregular heartbeat, or fainting.
- Uncontrollable movements of the face, tongue or limbs.
- Severe allergic reaction with rash, swelling, or breathing difficulty.
Safety essentials
- Fever combined with stiff muscles and confusion is a medical emergency. Stop the medicine and get emergency care immediately rather than waiting for it to pass.
- Chlorpromazine is not approved for dementia-related psychosis in older adults and carries a boxed warning for increased mortality in that population.
- Avoid alcohol and other sedating drugs, the combination can cause dangerous over-sedation.
- Protect your skin from strong sun, chlorpromazine increases the risk of sunburn.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.