Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Tetrabenazine.

Abnormal heart rhythms: Tetrabenazine may cause a heart rhythm problem called QT prolongation. If you have a history of QT prolongation, slow or irregular heartbeat, irregular heart rhythm, heart failure, Heart Attack, heart disease, taking other medications known to cause QT prolongation, or a family history of sudden cardiac death at less than 50 years of age, discuss with your doctor how Tetrabenazine may affect your medical condition, or how your medical condition may affect the dosing and effectiveness of Tetrabenazine. Your doctor will perform tests at regular intervals to monitor for any changes in your heart rhythm.

Depression: Tetrabenazine may cause depression. If you have depression or a history of depression, discuss with your doctor how Tetrabenazine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Tetrabenazine, and whether any special monitoring is needed. The symptoms of depression may be as severe as thinking about hurting yourself of others. If you experience these side effects or notice them in a family member who is taking Tetrabenazine, contact your doctor immediately.

If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking Tetrabenazine contact your doctor as soon as possible.

Drowsiness/reduced alertness: Tetrabenazine may cause drowsiness or dizziness, affecting your ability to drive or operate machinery. Avoid these and other hazardous tasks until you have determined how Tetrabenazine affects you.

Low blood pressure: Tetrabenazine may cause a decrease in blood pressure causing dizziness and fainting, especially when getting up from a sitting or lying position. Get up slowly from a sitting or lying position to avoid dizziness, fainting, or falling.

Neuroleptic malignant syndrome (NMS): Like other medications that affect chemical messengers in the brain, tetrabenazine can cause a potentially fatal syndrome known as neuroleptic malignant syndrome (NMS). If you notice the symptoms of NMS such as high fever, muscle stiffness, confusion or loss of consciousness, sweating, racing or irregular heartbeat, or fainting, get immediate medical attention.

Parkinsonism: Tetrabenazine works to reduce uncontrolled movement. Some people taking tetrabenazine have experienced tremor or stiff muscles with difficulty starting movement, a condition that mimics Parkinson's Disease. If you experience these signs, contact your doctor as soon as possible.

Pregnancy: Tetrabenazine should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Tetrabenazine, contact your doctor immediately.

Breast-feeding: Tetrabenazine may pass into breast milk. If you are a breast-feeding mother and are taking tetrabenazine, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Tetrabenazine have not been established for children.