PMS-Tetrabenazine: Uses, Side Effects and Dosage

ABOUT THIS MEDICATION

What the medication is used for:

pms-TETRABENAZINE has been prescribed to you by your doctor to treat your symptoms of a movement disorder which causes jerky, irregular, uncontrollable movements, such as those seen in Huntington’s chorea, hemiballismus, senile chorea, tic and Gille de la Tourette’s syndrome, and tardive dyskinesia.

What it does:

pms-TETRABENAZINE is one of a group of drugs called monoamine depleting agents. pms-TETRABENAZINE is thought to interfere with storage of some chemicals in the brain such as dopamine which is associated with movement disorders.

When it should not be used:

Do not take pms-TETRABENAZINE if you:

• are allergic to tetrabenazine
• are allergic to any of the non-medicinal ingredients listed below

• have symptoms of depression (e.g. feeling sad, crying spells,

  worthless, etc. – see table of Serious Side Effects below)

• have had depression, in the past or are currently being treated for

  depression, unless you are under the care of a supervising psychiatrist experienced with your disorder and pms-TETRABENAZINE.

• are taking or have recently taken Monoamine oxidase (MAO)

  inhibitor antidepressants (e.g. phenelzine sulphate, moclobemide).

• are taking or have recently taken a medication used to treat high

  blood pressure called reserpine

• have liver problems

What the medicinal ingredient is:

Tetrabenazine

What the non-medicinal ingredients are:

Corn starch, hydroxypropyl methylcellulose, iron oxide, lactose, magnesium stearate, talc.

What dosage forms it comes in:

25 mg tablets

WARNINGS AND PRECAUTIONS

BEFORE you use pms-TETRABENAZINE tell your doctor or pharmacist if you:

• have a history of or current episode of depression or suicidal thoughts
• are taking any prescription or over-the-counter medications, or are planning on taking any prescription or over-the-counter medications during your therapy. You should not take pms-TETRABENAZINE if you are taking reserpine or if you are taking a monoamine oxidase (MAO) inhibitor.
• have liver problems.
• have heart disease including irregular heartbeat
• have or have had breast cancer
• have or have had pituitary tumours
• have Parkinson’s disease

• drink alcohol. It is best not to drink alcohol while taking pms-

  TETRABENAZINE

• are pregnant, or thinking about becoming pregnant, or are breastfeeding

• if you have rare hereditary problems of galactose intolerance, the

  Lapp lactase deficiency or glucose-galactose malabsorption because pms-TETRABENAZINE contains lactose.

•

Depression:

pms-TETRABENAZINE may cause depression, thoughts of suicide or death or suicidal behavior in some patients. You and people close to you should watch for changes in your mood, or if you start to have thoughts about hurting yourself (see table of Serious Side Effects below) and report to your doctor immediately should they occur.

Driving vehicles or using machinery:

pms-TETRABENAZINE may cause drowsiness and low blood pressure. Driving, operating machinery, or performing other hazardous tasks should be avoided until you know how pms-TETRABENAZINE affects you.

Trouble swallowing:

pms-TETRABENAZINE may increase the chance that you will have trouble swallowing. Contact your doctor if this happens.

Irregular heartbeat:

pms-TETRABENAZINE may cause changes in the electrical currents in your heart. These changes may increase the risk of arrhythmias (irregular heartbeats), especially if used in combination with other drugs that have the same effect, or if you already have certain heart conditions. If you feel a change in your heart beat, if you feel dizzy or faint, you should seek immediate medical attention.

INTERACTIONS WITH THIS MEDICATION

You should tell your doctor if you are taking or have recently taken any medications (prescription, non-prescription or natural herbal) especially:

• monoamine oxidase (MAO) inhibitor (e.g. phenelzine sulphate,

  moclobemide).

• antidepressants such as fluoxetine, paroxetine, duloxetine,

  sertraline

• medicines that treat an irregular heartbeat such as quinidine,

  procainamide, amiodarone, sotalol

• antipsychotics or dopamine antagonists such as thioridazine,

  chlorpromazine haloperidol, metoclopramide, olanzapine, risperidone

• medicines for Parkinson’s Disease such as levodopa, amantadine

  or orphenadrine.

• reserpine

You should consult your doctor before you start any new medicines or before you stop or change doses of any other medicine you are taking while taking pms-TETRABENAZINE.

PROPER USE OF THIS MEDICATION

Usual dose:

How to take pms-TETRABENAZINE :

Adults

Take pms-TETRABENAZINE exactly as prescribed by your doctor.

• An initial starting dose of 12.5 mg two to three times a day is

  recommended. To obtain a 12.5 mg dose, the scored 25 mg tablet must be split with a pill cutter.

• This can be increased by 12.5 mg a day each week until the

  maximal tolerated and effective dose is reached.

• In most cases the maximal tolerated dose will be 25 mg three times

  a day. In some cases, higher doses may be prescribed.

• You should talk to your doctor before you stop taking your

  medication on your own. If you miss a dose and it is time or almost time for your next dose, take only the next scheduled dose and do not take 2 doses at once. If you miss several days contact your doctor as you may have to start with lower doses.

Geriatric Patients

Reduced initial and maintenance doses should be used. Your doctor will choose the appropriate dose.

Chlidren

Your doctor will decide the best dose.

Remember: This medicine has been prescribed only for you. Do not give it to anybody else, as they may experience undesirable effects, which may be serious.

Overdose

The signs and symptoms of overdose may include drowsiness, sweating, low blood pressure, and feeling cold.

In case of drug overdose, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.

SIDE EFFECTS AND WHAT TO DO ABOUT THEM

Like all medications, pms-TETRABENAZINE may cause some side effects. You may not experience any of them. However, some may be serious. Some of these side effects may be dose related. Consult your doctor if you experience these or other side effects, as the dose of pms-TETRABENAZINE may have to be adjusted.

The most common side effects of pms-TETRABENAZINE are:

• Signs and symptoms of Parkinsonism, such as tremors, difficulty starting or controlling movement, body stiffness, decrease in facial expressions, difficulty keeping your balance, speech problems, etc.
• Drowsiness, fatigue, weakness
• Depression
• Anxiety, nervousness
• Insomnia
• Restlessness, unable to sit or stand still
• Drooling
• Irritability, agitation
• Nausea, vomiting, stomach pain
• Confusion, disorientation
• Low blood pressure; symptoms may include dizziness when standing up
• Dizziness
• Weight increased
• Increased appetite

* If you think you have these side effects, stop taking the drug.

This is not a complete list of side effects. For any unexpected effects while taking pms-TETRABENAZINE, contact your doctor or pharmacist.

HOW TO STORE IT

• Keep all medication out of the reach of children.

• Store pms-TETRABENAZINE at room temperature between

  15°C and 30°C.

• Keep container tightly closed.
• If your doctor tells you to stop taking pms-TETRABENAZINE please return any leftover medicine to your pharmacist.

Reporting Side Effects

You can report any suspected side effects associated with the use of health products to Health Canada by:

• Visiting the Web page on Adverse Reaction Reporting

  (https://www.canada.ca/en/health-

  canada/services/drugs-health-products/medeffect-canada/adverse-reaction-reporting.html) for information on how to report online by mail or by fax; or

• Calling toll-free at 1-866-234-2345.

NOTE: Contact your health professional if you need information about how to manage your side effects. The Canada Vigilance Program does not provide medical advice.

MORE INFORMATION

If you want more information about pms-TETRABENAZINE:

• Talk to your healthcare professional
• Find the full product monograph that is prepared for healthcare professionals and includes this Consumer Information by visiting the Health Canada website (https://health-products.canada.ca/dpd-bdpp/index-eng.jsp), or by contacting the sponsor Pharmascience Inc. at: 1-888-550-6060.

Pharmascience Inc.

Montréal, Québec

H4P 2T4

www.pharmascience.com

Last revised: August 28, 2020.