Drug information of Tetrabenazine
Tetrabenazine formerly used as an antipsychotic but now used primarily in the symptomatic treatment of various hyperkinetic disorders . It is a monoamine depletor and used as symptomatic treatment of chorea associated with Huntington's disease . FDA approved on August 15, 2008.
Mechanism of effect
Tetrabenazine is a reversible human vesicular monoamine transporter type 2 inhibitor. It acts within the basal ganglia and promotes depletion of monoamine neurotransmitters serotonin, norepinephrine, and dopamine from stores.
It also decreases uptake into synaptic vesicles . Dopamine is required for fine motor movement, so the inhibition of its transmission is efficacious for hyperkinetic movement
The precise mechanism of action of tetrabenazine is unknown. Its anti-chorea effect is believed to be due to a reversible depletion of monoamines such as dopamine, serotonin, norepinephrine, and histamine from nerve terminals.
Tetrabenazine reversibly inhibits vesicular monoamine transporter 2, resulting in decreased uptake of monamines into synaptic vesicles, as well as depletion of monoamine storage.
Following oral use , absorption is 75%.and most of tetrabenazine hepatically metabolized and the metabolites are renally eliminated.
The starting dose should be 12.5 mg per day given once in the morning. After one week, the dose should be increased to 25 mg per day given as 12.5 mg twice a day.
Tetrabenazine Tablets should be titrated up slowly at weekly intervals by 12.5 mg daily, to allow the identification of a tolerated dose that reduces chorea.
If a dose of 37.5 to 50 mg per day is needed, it should be given in a three times a day regimen. The maximum recommended single dose is 25 mg.
Side effectsnausea , Headache , insomnia , decreased appetite , vomiting , vertigo , Depression , anxiety , dysphagia , ataxia , tiredness , shortness of breath , trouble in sleeping
InteractionsPimozide , Amitriptyline , Amiodarone , Erythromycin , Procarbazine , Thioridazine , Citalopram , Phenelzine , Quinidine , isocarboxazid , Arsenic , Droperidol , Cisapride , Fluoxetine , Hydroxychloroquine , Clarithromycin , Clozapine , Linezolid , Tranylcypromine , Reserpine , safinamide , rasagiline , Dolasetron , vandetanib , sparfloxacin , Mefloquine , Dofetilide , Inotuzumab , Promazine , Halofantrine , Grepafloxacin , Molindone , Trimeprazine , Asenapine , Pimavanserin , Entrectinib , Cariprazine , Dacomitinib , Bromopride , Naltrexone and Bupropion , Bepridil , bedaquiline
Tell your doctor if you have any of followings:
• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
• Trouble controlling body movements that is new or worse.
• Change in balance.
• Shakiness, trouble moving around, or stiffness.
• Feeling very sleepy.
• Feeling agitated.
• Feeling confused.
• A fast heartbeat.
• A heartbeat that does not feel normal.
• Dizziness or passing out.
Points of recommendation
- Avoid driving and doing other tasks or actions that call for you to be alert until you see how tetrabenazine affects you.
- To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
- Have your blood pressure checked often. Talk with your doctor.
- Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
- If you have Huntington's disease , your signs can still get worse while you use drugs like this one. Call your doctor right away if you have any signs that are new or worse.
- Tell your doctor if you are pregnant or plan on getting pregnant or breast feeding.