Tetrabenazine - Oral

Tetrabenazine is used to treat nervous system disorders that cause jerky and irregular uncontrollable movements.

This medicine may also be used to treat tardive dyskinesia (a condition which causes uncontrollable twitching movements of the mouth, tongue and limbs).

Take Tetrabenazine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

You may take this medicine with or without food. Try to take it at the same time each day.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type of your condition and your response to the medication.

Tetrabenazine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.

Alert your doctor if you have the following conditions:

• having thoughts of self-harm
• depression
• symptoms similar to Parkinson's disease (disorder that affects the movement of a person, causing symptoms such as tremors, muscle stiffness, slowed movement, and impaired balance or walking)
• liver disease

as Tetrabenazine may not be suitable for you.

Do not take Tetrabenazine if you are currently taking or have taken a medicine that is used to treat depression known as a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine and tranylcypromine in the last 14 days.

Do not take Tetrabenazine with medicines used to treat high blood pressure and other medicines used for movement disorders or tardive dyskinesia. Please see the section "Can I take this with other medicines?" below for more information.

Inform your doctor if you have the following conditions:

• history of depression
• previous suicide attempts or suicidal thoughts
• breast cancer
• aspiration pneumonia (a lung infection that may occur when oral or stomach contents are breathed into the lungs or airways leading to the lungs instead of being swallowed)
• congenital long QT syndrome (an inherited disease causing abnormally fast and erratic heartbeats)
• history of heart rhythm disorder

Let your doctor know if you are pregnant or breastfeeding.

Individuals who are poor metabolisers of CYP2D6 may experience enhanced effects of Tetrabenazine. Your doctor may advise you to undergo genetic testing before starting your treatment with this medicine. If you know you have this gene type, inform your doctor.

Why is it important to keep my appointments with the doctor?

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.

• Routine tests (e.g. liver function, ECG [test used to record the electrical activity of the heart]) may be done while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
• Your blood pressure may fall to unsafe levels without you noticing it. Monitor your blood pressure regularly during treatment.
• Regular monitoring for signs of depression may also be needed.

Tetrabenazine may cause drowsiness. If affected, do not drive or take part in any activity in which you need to be alert.

This medicine may cause your blood pressure to fall suddenly when you get up from a sitting or lying down position and you may feel giddy. To minimise this problem, stand up slowly.

Other side effects include any of the following: headache, nausea, diarrhoea, vomiting, constipation, decreased appetite, tiredness, and difficulty sleeping.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:

• having thoughts of self-harm, unusual changes in mood or behaviour (being too depressed, agitated, or having compulsive and impulsive behaviour)
• fast or abnormal heartbeat, excessive sweating, muscle cramps or stiffness
• difficulty swallowing
• tremors, slowed movements, stiffness of the arms and legs, imbalance while walking, uncontrollable movements such as twitching and jerking

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.

Do not take Tetrabenazine if you are currently taking or have taken a medicine that is used to treat depression known as a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine and tranylcypromine in the last 14 days.

Do not take Tetrabenazine with the following medicines:

• reserpine (medicine for high blood pressure)
• other medicines used for movement disorders or tardive dyskinesia e.g. deutetrabenazine, valbenazine

Inform your doctor and pharmacist if you are taking any of these medicines:

• medicines to treat depression e.g. fluoxetine, paroxetine
• medicines for irregular heartbeat e.g. quinidine, procainamide, amiodarone, sotalol
• medicines for mood disorders e.g. chlorpromazine, thioridazine, haloperidol
• medicines that cause drowsiness or affect your concentration
• other medicines for high blood pressure
• certain antibiotics e.g. gatifloxacin, moxifloxacin

This list does not include all medicines that may interact with Tetrabenazine.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements, and medicines that you buy without a prescription.

Avoid alcohol. Alcohol intake may worsen the drowsiness caused by Tetrabenazine.

Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.