Tetrabenazine (Nitoman® and generic forms) belongs to a group of medications called monoamine depleting agents.

What is this medication used for?

Tetrabenazine is approved by Health Canada for the treatment of Tourette syndrome and movement disorders such as motor and vocal tics in children and adolescents. It is also approved for the treatment of other movement disorders such as Huntington’s chorea.

When potential benefits outweigh risks, tetrabenazine may be used “off-label” for the treatment of unusual involuntary movements associated with antipsychotic medications (called “tardive dyskinesia” or “dystonia”). Learn more about off-label medication use: http://bit.ly/KMH-off-label-use

Tell your doctor or pharmacist if you:

• Have allergies or bad reactions to a medication
• Take (or plan to take) other prescription or non-prescription medications, including natural medicines. Some medications interact with tetrabenazine. Your doctor may adjust medication doses or monitor for side effects
• Are lactose intolerant
• Have a history of seizures, depression, liver or kidney disease
• Have a history (or family history) of heart disease, arrhythmia or “familial long QT syndrome”
• Miss a menstrual period, are pregnant, breast-feeding or planning a pregnancy
• Use alcohol or drugs. Taking tetrabenazine together with certain substances may cause a bad reaction. Learn more at www.DrugCocktails.ca

When will the medication start to work?

Tetrabenazine needs to be taken for 1 to 2 weeks before you notice improvement in your symptoms. You may notice improvement earlier if tetrabenazine is combined with other medications. A delay in response is normal.

It is important that you continue taking tetrabenazine regularly, even if you are feeling well or there are no improvements in the first few weeks. Talk with your doctor if you feel that tetrabenazine has not been helpful or if side effects are too bothersome. Your doctor may recommend switching you to a different medication.

This medication is not addictive. Do not stop taking it before talking to your doctor.

Possible common or serious side effects:

• Drowsiness, dizziness, fatigue or weakness
• Difficulty sleeping
• Feelings of agitation
• Stomach ache or nausea

Contact your doctor immediately if you experience:

• Unexplained rash, fever or excessive sweating
• Fainting, feeling lightheaded or difficulty with balance
• Breast tenderness or swelling (males and females)
• Feelings of restlessness, fast or irregular heartbeat
• Shaking, pain or weakness
• Unusual movements of fingers, toes, neck, lips or tongue
• Thoughts of hurting yourself, suicide, increased hostility or worsening symptoms
• Unexplained confusion
• In females: changes in menstrual cycle

How do I take this medication?

Tetrabenazine is usually taken two to three times a day, at the same time(s) each day. It can be taken with or without food. If you find that taking this medication causes stomach discomfort, try taking it with food. Usually, you will start with a low dose and slowly increase this dose over several days or weeks, based on how you tolerate it.

Tetrabenazine is available in tablets that are taken by mouth. If necessary, tablets may be broken in half, but they should not be crushed or chewed.

What precautions should my doctor and I be aware of when taking this medication?

• Many medications may interact with tetrabenazine, including antipsychotics, cannabinoid-containing products, CNS depressants, monoamine oxidase inhibitors, sleep aides, and several other medications.
• If you are (or begin) taking any other prescription, over-the-counter medication, natural health product, or supplement, check with your doctor or pharmacist to see if they are safe to use.
• While taking this medication, if you feel dizzy, drowsy, or slowed down, do not drive a car or operate heavy machinery. Alcohol could make this worse. Try to avoid alcohol while taking tetrabenazine.
• Tetrabenazine can cause a rare side effect called “neuroleptic malignant syndrome.” Symptoms include severe muscle stiffness, high fever, sweating, increased or irregular heartbeat, and decreased blood pressure.

What special instructions should I follow while using this medication?

• Keep all appointments with your doctor and the laboratory.
• Your doctor may order certain assessments and tests (for example, abnormal involuntary movement testing).
• This is to monitor your condition, check how you are responding to tetrabenazine, and monitor for side effects.
• Do not allow anyone else to use your medication.

What should I do if I forget to take a dose of this medication?

If you forget to take a dose, take the missed dose as soon as you remember. However, if it is within 4 hours of your next scheduled dose, skip the missed dose and continue with your regular schedule. DO NOT double your next dose to try to ‘catch up’.

How do I store this medication?

Keep this medication in the original container, stored at room temperature away from moisture and heat, and protected from light. Keep this medication out of reach and sight of children.

How does this medication work?

Tetrabenazine works by affecting the levels of the brain chemicals dopamine, serotonin, and norepinephrine (as a group, these chemicals are sometimes called ‘monoamines’). The exact way tetrabenazine improves the symptoms of Tourette syndrome and other movement disorders is not fully known.

How well does the medication work in children and adolescents?

Current evidence supports the use of tetrabenazine for the treatment of Tourette syndrome and tic disorders in children and adolescents. It has been shown to reduce the number of motor and vocal tics, as well as the severity of symptoms. In one study, children with various movement disorders (chorea, dystonia) that did not respond to treatment with other medications were treated with tetrabenazine. Three-quarters of those patients showed some degree of improvement. For certain conditions, adding behavioural therapy and counselling to tetrabenazine treatment may increase the chance for benefit.

How long should I take the medication for?

This depends on the symptoms you have, how frequently they occur, and how long you have had them. Most people need to take tetrabenazine for several months. Your doctor will discuss the benefits and risks of taking tetrabenazine with you. At this time, you can also discuss how long you might need to take this medication.

Do not increase, decrease, or stop taking this medication without discussing it with your doctor. If you stop taking tetrabenazine suddenly, it is possible that your symptoms may return or you may have a bad reaction.