Largactil (chlorpromazine)

Largactil (chlorpromazine)

Brand name: Largactil®.
Active ingredient name: Chlorpromazine.
Type of medication: Typical antipsychotic.
Available in Canada from: Rhone-Poulenc Rorer-Ethical Division Products.
Form: Oral tablets.
Generic: Yes: Teva-Chlorpromazine.
Listed on Ontario formulary: Yes.
OHIP+ coverage: Largactil brand not covered, Teva-Chlorpromazine covered.

What is Largactil used for?

Largactil is used to treat the symptoms of schizophrenia and other psychotic illnesses. It is also used to prevent and treat nausea and vomiting, for relief of restlessness and anxiety before surgery, and to manage symptoms of mania in bipolar disorder. It is used to treat adults and children. In children it is most commonly used for nausea and vomiting, to calm them before surgery and in some cases for behavioural issues.

How should I take Largactil?

  • Largactil is available as 25 mg, 50 mg and 100 mg tablets.
  • Adults: The usual dosage range of Largactil for schizophrenia and psychotic illnesses is 50 mg - 400 mg per day. Doses above this range can be used for some individuals.
  • Discuss your individual dose with your doctor.
  • Children: Your child’s doctor will decide what is the best dose based on your child’s symptoms, age, weight and response. Discuss the dose with your doctor.

What are the most common side effects seen with Largactil

The most common side effects of Largactil include:
  • Abnormal movements (extrapyramidal symptoms)
  • Changes in monthly menstrual cycle (amenorrhea)
  • Decreased sexual interest and/or function
  • Swelling of breasts and milk production in males and females
  • Sleepiness
  • Constipation
  • Dry mouth
  • Dizziness
  • Postural low blood pressure (ongoing from sitting to standing)
  • Weight gain
  • Increased sensitivity to sun

What are rare but potentially serious adverse effects with Largactil?

  • Decrease in white blood cell count (agranulocytosis)
  • Liver dysfunction (jaundice)
  • Neuroleptic malignant syndrome (NMS)
  • Torsades de pointes (serious heart arrhythmia)
  • Systemic lupus


Elderly individuals with dementia-related psychosis treated with antipsychotic medication are at an increased risk of death compared to individuals not receiving antipsychotics. Most deaths appear to be either cardiovascular or infectious. Largactil is not approved for the treatment of dementia-related psychosis. Some individuals with dementia may, however, be treated with this medication. Discuss the potential risks and benefits of this medication with your doctor for this indication.

What medications interact with Largactil?

Tell all your doctors, pharmacists and dentist that you are taking Largactil. You should also tell your doctor or pharmacist if you are taking any other medications, including those obtained without a prescription, and herbal and vitamin products.

The following types of medications may interact with Largactil

  • Certain antibiotics (e.g., ciprofloxacin, clarithromycin)
  • Certain medications for allergies (e.g., Benadryl [diphenhydramine])
  • Certain medications for sleep (e.g., lorazepam, zopiclone)
  • Certain medications for pain (e.g., fentanyl)
Avoid drinking alcohol or using illegal drugs while taking Largactil.