Pimozide: Uses, Side Effects and Dosage

Serious warnings and precautions box

What is PIMOZIDE used for:

PIMOZIDE is used to control the symptoms of chronic schizophrenia where the main symptoms do not include excitement, agitation or hyperactivity.

PIMOZIDE should not be used to manage mania or acute schizophrenia.

How PIMOZIDE works:

PIMOZIDE belongs to a group of medicines called antipsychotic drugs. Antipsychotic medications affect dopamine and serotonin (chemicals found in the brain) that allow for the communication between your nerve cells. Exactly how this medication works is not known. However, it seems that PIMOZIDE corrects the balance of dopamine and serotonin in your body.

The ingredients in PIMOZIDE are:

Medicinal ingredients: Pimozide

Non-medicinal ingredients: Anhydrous lactose, croscarmellose sodium, and magnesium stearate.

The 4 mg tablets also contain: additional D & C yellow #10 Aluminium Lake 14-18% and indigotine AL Lake 12-14% (Blue #2).

PIMOZIDE comes in the following dosage forms:

Tablets: 2 mg and 4 mg.

Do not use PIMOZIDE if:

• you are allergic to pimozide or to any of the ingredients in PIMOZIDE or its container
• you have a medical condition known as pheochromocytoma (a tumor of the adrenal gland)

• you have a severe heart problem or a family history of heart problems such as:

  • long QT syndrome
  • Torsade de Pointes
  • problem with your heart rhythm
• you have a severe blood vessel or blood disorder
• you have severe kidney problems
• you have had brain damage
• you have liver problems
• you have a blood cell disorder such as anemia, leukopenia (low white blood cell count), thrombocyto-penia (low platelet count)
• you have drowsiness, slow breathing, weak pulse

• you have decreased alertness caused by taking certain medications or drinking alcohol

• you are going to receive anesthesia in the spine or for a region (such as an arm, leg or the lower part of your body)
• you have Parkinson’s syndrome
• you have depression
• you are under treatment of tics
• you have family history of irregular heartbeats.
• you have central nervous system depression or comatose states

• you are taking the following drugs:

  • CYP 3A4-inhibiting drugs such as antifungal drugs (e.g. micronazole, ketonazole), antiviral (e.g. saquinavir, ritonavir), macrolide antibiotics (e.g. clarithromycin and erythromycin) and nefazo-done.
  • CYP 2D6-inhibiting drugs such as quinidine
  • Selective Serotonin Reuptake Inhibitor antidepressants such as sertraline, paroxetine, citalopram and escitalopram.

To help avoid side effects and ensure proper use, talk to your healthcare professional before you take PIMOZIDE. Talk about any health conditions or problems you may have, including if you:

• have a history of problems with the heart and/or blood vessels
• are prone to low blood pressure (hypotension)

• are at risk for developing blood clots. Risk factors include:

  • having a family history of blood clots
  • being over the age of 65
  • smoking or being overweight
  • having a recent major surgery (such as hip or knee replacement)
  • not being able to move due to air travel or other reasons
  • taking oral birth control ("The Pill")
• have increased pressure in the eye (glaucoma) or suffer from enlargement of the prostate (prostatic hypertrophy)
• are addicted to alcohol. You should not take PIMOZIDE if you are under the effects of alcohol

• are pregnant, think you might be pregnant or plant to become pregnant

• are taking barbiturates, painkillers, narcotics or antihistamines or other drugs that make you drowsy
• have or ever had a blackout or seizure
• are breast feeding or are planning to breastfeed. PIMOZIDE can pass into your breast milk. You should not breast-feed while taking this medication

• have a history of breast cancer

  • have one of the following rare hereditary diseases:

    • Galactose intolerance
    • Lapp lactase deficiency
    • Glucose-galactose malabsorption

Because lactose is a non-medicinal ingredient in PIMOZIDE

• have or have had low white blood cell counts in your blood
• have too much or not enough of certain minerals in your body such as potassium, magnesium and calcium
• have diabetes
• have an eating disorder or are on an extreme diet

Other warnings you should know about:

Driving and using machines: PIMOZIDE may make you less alert. This may be more likely to happen when you first start taking PIMOZIDE. You should avoid driving a car or using machinery until you know how PIMOZIDE affects you.

Effects on Newborns: You should not take PIMOZIDE while you are pregnant or if you are planning on becoming pregnant unless you have talked to your healthcare professional about it. If you took PI-MOZIDE at any time while you were pregnant or if you took it before you became pregnant, the follow-ing symptoms may happen in your newborn baby:

• shaking
• stiffness in their muscles and/or weakness
• sleepiness
• agitation
• breathing problems
• difficulty feeding

Get medical help right away if your newborn baby has any of these symptoms. In some cases, the new-born may experience symptoms that are severe and require the newborn to be hospitalized.

Neuroleptic Malignant Syndrome (NMS): NMS is a potentially life-threatening reaction that has been reported with the use of antipsychotic drugs. Symptoms of NMS include:

• severe muscle stiffness or inflexibility with high fever,
• rapid or irregular heartbeat,
• sweating,
• state of confusion or reduced consciousness.

Call your healthcare professional right away if you start to have any of these symptoms while taking PIMOZIDE.

Tardive Dyskinesia: PIMOZIDE, like other antipsychotic medications, can cause potentially irreversible muscle twitching or unusual/abnormal movement of the face or tongue or other parts of your body.

Dehydration and Overheating: PIMOZIDE may interfere with your body’s ability to adjust to heat. It is important not to become too hot or dehydrated while you are taking PIMOZIDE.

• Do not exercise too much.
• In hot weather, stay inside in a cool place if possible.
• Stay out of the sun.
• Do not wear too much clothing or heavy clothing.
• Drink plenty of water.

Increased levels of prolactin: PIMOZIDE can raise your levels of a hormone called “prolactin”. This is measured with a blood test. Symptoms may include:

• In men:

  • swelling in the breast
  • difficulty in getting or maintaining an erection or other sexual dysfunction

• In women:

  • discomfort in the breasts
  • leaking of milk from the breasts (even if not pregnant)
  • missing your menstrual period or other problems with your cycle

If you have high levels of prolactin and a condition called hypogonadism, you may be at an increased risk of breaking a bone due to osteoporosis. This occurs in both men and women.

Check-ups and monitoring: You will have regular visits with your healthcare professional, before, during and at the end of your treatment. They will:

• Check that your heart is working properly
• Perform blood tests to check your blood sugar levels, blood fat levels, blood and liver health
• Monitor your blood pressure
• Check your body weight

Tell your healthcare professional about all the medicines you take, including any drugs, vitamins, minerals, natural supplements or alternative medicines.

Serious drug interactions:

The following may also interact with PIMOZIDE:

• medicines used to treat anxiety.
• muscle relaxants, medicines used as anaesthetics.
• medicines used to treat fits or convulsions.
• medicines used to lower the blood pressure.
• cabergoline, a medicine used to treat high levels of prolactin hormone.
• metrizamide, a radiocontrast agent used to determine the presence of abnormalities in the spi-nal column, spinal canal, and central nervous system (CNS).
• guanethidine, guanadrel, medicines used to lower blood pressure.
• grepafloxacin, sparfloxacin, medicines used as antibiotics.
• cisapride, a medicine used to treat heartburn.
• atropine-like drugs, used to treat symptoms of bradycardia, pesticide poisoning etc.
• narcotic pain relievers (e.g., codeine).
• medicines used to aid sleep, drowsiness-causing antihistamines (e.g., diphenhydramine), other medicines that may make you drowsy.
• levodopa, a medicine used to treat the symptoms of Parkinson's disease.
• diuretics, medicines used to treat high blood pressure.
• laxatives and enemas, medicines used to treat constipation.
• high dose corticosteroids, medicines used to provide relief for inflamed areas of the body.
• alcohol. The effects of alcohol can be made worse if you drink alcohol while taking PIMOZIDE. Do NOT drink alcohol while taking PIMOZIDE.
• grapefruit juice.
• betel nut.

How to take PIMOZIDE:

• Take PIMOZIDE exactly as your healthcare professional tells you to take it. Even if you feel bet-ter, do NOT change your dose or stop taking PIMOZIDE without speaking to your healthcare professional.
• Your healthcare professional has decided on the best dosage for you based on your individual situation, but may change your dose depending on how you respond.
• Take PIMOZIDE tablets with a full glass of water in the morning.

Usual dose:

The usual adult starting dose is 2 to 4 mg once a day in the morning. Your healthcare professional will monitor your health and may reduce, increase or stop your dose depending on your current health, if you take certain other medications or if you have certain side effects. Your healthcare professional will decide the best dose for you.

Overdose:

Symptoms of an overdose with PIMOZIDE may include

• irregular heartbeat
• low blood pressure
• agitation
• confusion
• drowsiness
• dizziness
• muscle stiffness or twitching
• increased salivation
• trouble swallowing
• weakness
• loss of balance or coordination
• fainting

Missed dose:

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take the next dose at your regular. Do NOT double your dose to make up the missed dose.

Possible side effects from using PIMOZIDE:

These are not all the possible side effects you may have when taking PIMOZIDE. If you experience any side effects not listed here, tell your healthcare professional.

Side effects may include:

• sweating
• loss of bladder control
• dizziness
• drowsiness
• dry mouth
• stuffy nose
• nausea and vomiting
• headache
• menstrual changes
• change in libido
• swelling of the breasts and milk production in both men and women
• weight changes
• blurred vision

Serious side effects and what to do about them

If you have a troublesome symptom or side effect that is not listed here or becomes bad enough to interfere with your daily activities, tell your healthcare professional.

Reporting Side Effects

Storage:

Store PIMOZIDE tablets at room temperature (15^oC-30^oC) in well-closed containers.

Do not use after the expiry date shown on the bottle.

Keep out of reach and sight of children.

If you want more information about PIMOZIDE:

• Talk to your healthcare professional.
• Find the full product monograph that is prepared for healthcare professionals and includes the Pa-tient Medication Information by visiting the Health Canada Drug Product website (https://www.can-ada.ca/en/health-canada/services/drugs-health-products/drug-products/drug-product-data-base.html); the manufacturer’s website (http://www.aapharma.ca/en/); or by calling 1-877-998-9097.

Date of Authorization: 2026-10-27