Xenazine

The active ingredient in Xenazine is tetrabenazine, which is a VMAT2 inhibitor. Tetrabenazine is thought to disrupt the VMAT2 protein in your brain, which aids in the treatment of involuntary movements (chorea) from Huntington's disease. This reduces the amount of certain neurotransmitters released in the brain (such as dopamine, serotonin, norepinephrine, and histamine), which may impact movement.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide, before using Xenazine. However, the following is a synopsis of the general guidelines for the use of Xenazine:

• Your doctor may occasionally adjust your dose to provide the optimum results. Do not change your dose of Xenazine or take it for longer than indicated.
• You can take these tablets with or without food.
• Call your doctor if your symptoms persist or worsen.

The most common side effects of tetrabenazine seen in clinical trials as compared to placebo include:

• Sleepiness.
• Shortness of breath.
• Increased risk of depression.
• Trouble sleeping.
• Restlessness.
• Nausea.
• Vomiting.
• Balance issues and falls.
• Anxiety.
• Irritability.
• Parkinsonism.

Some individuals may experience serious side effects while using Xenazine. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Suicidal thoughts and ideations include depression, worry, panic attacks, problems sleeping, feelings of anger or irritability, and restlessness.
• Neuroleptic malignant syndrome (NMS) symptoms include a high fever, sweating, rigid muscles, confusion, loss of awareness of your surroundings, and a fast or irregular heart rate.
• Abnormal cardiac rhythm, particularly QT prolongation, can cause chest pounding, shortness of breath, chest pain, fainting, and lightheadedness.
• Akathisia, which is defined as restlessness, difficulty sitting still, squirming or fidgeting, and being irritated. Tardive dyskinesia is also a theoretical risk.
• Low blood pressure when you change position (orthostatic hypotension).

These are not all of the possible side effects of Xenazine. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Xenazine, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including whether you have:

• Severe or untreated depression.
• Suicidal thoughts or behaviors.
• Liver disease.
• Irregular blood pressure.
• Do not use Xenazine if you have used an MAOI (monoamine oxidase inhibitor) in the past 14 days.
• Past or present breast cancer.
• Heart disease.
• Long QT syndrome.
• Recently had a heart attack.

Boxed Warning

Tetrabenazine carries a serious warning for increased risk of depression and suicidal thoughts or behaviour, especially in patients with Huntington’s disease. While it helps manage choreiform movements, the risk of suicidality must be carefully weighed, and patients should be closely monitored for new or worsening depression or behavioural changes. Those with a history of depression or prior suicide attempts need extra caution, and the medication is not suitable for individuals who are actively suicidal or have untreated or poorly managed depression. Families and caregivers should be informed and encouraged to report any concerning behaviour immediately.

• Suicidal ideas or behaviour.
• Depression that has not been treated or is just partially treated.
• Liver failure.
• In the last 14 days, you have taken or are using monoamine oxidase inhibitors (MAOIs), such as selegiline, phenelzine (Nardil), or tranylcypromine (Parnate).
• Taking tetrabenazine (Xenazine) alongside Austedo (deutetrabenazine) or Ingrezza (valbenazine).

It may take 2 to 3 weeks for you to observe an improvement in your chorea symptoms after starting Xenazine. Continue to take your medication as prescribed by your doctor, even if you do not see immediate results.

When Xenazine is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• Reserpine.
• Monoamine oxidase inhibitors (MAOI).
• Alcohol or other sedative substances.
• Antipsychotic medications (e.g., chlorpromazine, haloperidol, thioridazine, ziprasidone), antibiotics (e.g., moxifloxacin), Class 1A (e.g., quinidine, procainamide) and Class III (e.g., amiodarone, sotalol) antiarrhythmic medications, and any other medication known to prolong the QTc interval.
• Neuroleptic medicines include chlorpromazine, haloperidol, olanzapine, risperidone, thioridazine, and ziprasidone.
• Strong CYP2D6 inhibitors.
• Deutetrabenazine or valbenazine.

The typical dosage form of Xenazine is a capsule or tablet, commonly used orally one to three times per day, with a maximum dose of 50 mg to 100 mg per day.

The dose of Xenazine varies from person to person and is determined by how you respond to the medication, whether you take other medications that interact with Xenazine, or whether you have certain genetics that affect how well the medication is broken down in your body.

Store at room temperature and keep out of reach of children.

Bausch Health Companies Inc. is the company that manufactures Xenazine.

There are several lower-cost generics available.

You should not discontinue this medication abruptly, as your symptoms may recur. Talk to your doctor before discontinuing this medication.

It is not known if Xenazine is safe to use during pregnancy. However, animal studies have shown that the medication can cause harm to unborn babies. Talk to your doctor if you are already pregnant or if you have any plans to become pregnant. They will know or recommend what is best for you.

Can Xenazine be used if I am breastfeeding?

It is not known whether Xenazine is safe to use while breastfeeding. Talk to your doctor if you are already breastfeeding or if you have any plans to breastfeed. They will know or recommend what is best for you.