Xenazine Oral

Tetrabenazine is used to decrease the uncontrollable movements (chorea) caused by Huntington\'s disease. However, it is not a cure for the disease. Reducing the chorea will help you take part in more of your normal daily activities. This medication is thought to work by decreasing the amount of certain natural substances in the brain (monoamines such as dopamine, serotonin, and norepinephrine), which are involved with nerve and muscle function. Tetrabenazine belongs to a class of drugs called monoamine depletors.

How to use Xenazine Oral
Read the Medication Guide provided by your pharmacist before you start using tetrabenazine and each time you get a refill. If you have any questions, consult your doctor or pharmacist.
Take this medication by mouth with or without food, usually once a day in the morning when you first start treatment or as directed by your doctor. Your doctor may gradually increase your dose to 2 or 3 times a day over several weeks. A slow increase in your dose will help your doctor find the best dose for you while keeping side effects as low as possible.
Dosage is based on your medical condition and response to treatment. Your doctor may perform a blood test to see how your body handles this medication and to help determine the right dose for you. Do not take more of this medication than prescribed because doing so may increase your risk of side effects.
Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day.
If you stop taking this drug for several days, then start taking it again, you may need to slowly increase your dose until you reach the regular dose you had been taking. Follow your doctor\'s directions on how to restart treatment.
Tell your doctor if your uncontrolled movements do not improve or if they worsen.

See also Warning section.
Drowsiness, trouble sleeping, tiredness, dizziness, nausea, and vomiting may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Your doctor may need to adjust your dose to reduce these side effects.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Sometimes tetrabenazine can cause side effects that are similar to the symptoms of worsening Huntington\'s disease. Your doctor may need to adjust your dose to see if these side effects are due to the drug or to the disease. Tell your doctor immediately if any of these serious side effects occur: mental/mood changes (such as new/worsening depression, suicidal thoughts/attempts, problems with thinking), Parkinson\'s disease symptoms (such as shaking/tremors, muscle stiffness, slowed movement, loss of balance), trouble swallowing, restlessness.
Tell your doctor immediately if any of these unlikely but serious side effects occur: uncontrolled muscle movements of the face (such as lip smacking, unusual tongue movements), signs of increased prolactin hormone (such as enlarged breasts, abnormal breast milk production, decreased sexual ability, a change in menstrual cycle).
Seek immediate medical attention if you have any of these rare but serious (possibly fatal) side effects: fast/irregular heartbeat, severe dizziness, fainting, symptoms of neuroleptic malignant syndrome (such as fever, muscle stiffness, confusion, sweating, unusual change in the amount of urine, dark urine).
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking tetrabenazine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: liver problems, depression that is untreated or not responding to treatment, thoughts of suicide.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: breast cancer.
Tetrabenazine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using tetrabenazine, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow/irregular heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/\"water pills\") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using tetrabenazine safely.
This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
It is not known whether this drug passes into breast milk. Consult your doctor before breast-feeding.

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.
This drug should not be used with the following medications because very serious interactions may occur: MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine), levodopa, reserpine.
Do not take tetrabenazine while you are using reserpine. You must wait at least 20 days after stopping reserpine before you start treatment with tetrabenazine.
If you are currently using any of these medications listed above, tell your doctor or pharmacist before starting tetrabenazine.
Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use.
Many drugs besides tetrabenazine may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, pimozide, procainamide, quinidine, sotalol, thioridazine, macrolide antibiotics (such as erythromycin), among others.
Other medications can affect the removal of tetrabenazine from your body, which may affect how tetrabenazine works. Examples include quinidine, SSRI antidepressants such as fluoxetine and paroxetine, among others. Your doctor will need to adjust your tetrabenazine dose if you are also taking any of these medications.
This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: muscle stiffness/pain, fixed upward position of the eyeballs, sweating, dizziness, severe drowsiness.

NOTES:
Do not share this medication with others.
Laboratory and/or medical tests may be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

MISSED DOSE:
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE:
Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.
Information last revised October 2011. Copyright(c) 2011 First Databank, Inc.