Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes Nitoman (Tetrabenazine). If you are concerned about side effects, discuss the risks and benefits of Nitoman (Tetrabenazine) with your doctor.

The following side effects have been reported by at least 1% of people taking Nitoman (Tetrabenazine). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• difficulty sleeping
• dizziness
• drooling
• drowsiness
• fatigue
• nausea
• severe dizziness when standing or sitting from a lying position
• stomach pain
• vomiting
• weakness

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• agitation
• anxiety
• confusion, disorientation
• difficulty swallowing
• increasing restlessness
• irritability
• Low Blood Pressure
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• signs of parkinsonism (e.g., tremor, muscle stiffness, difficulty starting movement, decrease in facial expressions, speech problems)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of heartbeat problems (e.g. dizziness, sensation of a pounding or irregular heartbeat, fainting or seizures)
• signs of neuroleptic malignant syndrome (e.g., high Fever, muscle stiffness, confusion, profuse sweating, racing or irregular heartbeat)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Nitoman (Tetrabenazine).

Each round, yellowish-buff tablet with "CL 25" imprinted across one face and a single break bar on the other, contains Nitoman (Tetrabenazine) 25 mg. Nonmedicinal ingredients: corn starch, lactose, talc, magnesium stearate, and iron oxide.

Do not take Nitoman (Tetrabenazine) if you:

• are allergic to Nitoman (Tetrabenazine) or any ingredients of the medication
• have untreated or poorly treated signs of Depression (e.g. poor concentration, changes in sleep, decreased interest in activities)
• have had depression or are currently being treated for depression, unless you are under the care of a psychiatrist experienced with your condition and the medication Nitoman (Tetrabenazine)
• have taken a monoamine oxidase inhibitor (MAOI) within the last 14 days
• plan to start taking a MAOI in the next 14 days
• have reduced liver function
• are taking a medication for high blood pressure called reserpine

There may be an interaction between Nitoman (Tetrabenazine) and any of the following:

• alcohol
• Alfuzosin
• amantadine
• Amiodarone
• antihistamines (e.g., cetirizine, Diphenhydramine, Hydroxyzine)
• antipsychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, olanzepine, Quetiapine, Risperidone)
• aripirazole
• azelastine
• "azole" antifungals (e.g., fluconazole, itraconazole, Voriconazole)
• Baclofen
• barbiturates (butabarbital, Phenobarbital)
• benzodiazepines (e.g., clobazem, Diazepam, Lorazepam)beta-2 agonists (e.g., salmeterol, formoterol)
• Buprenorphine
• Bupropion
• Buspirone
• Capecitabine
• Carbamazepine
• chloral hydrate
• chloroquine
• Cimetidine
• Clonidine
• Cobicistat
• cocaine
• cyproheptadine
• Darifenacin
• delavirdine
• Disopyramide
• Domperidone
• Dronedarone
• efavirenz
• Famotidine
• Fingolimod
• Flecainide
• Gabapentin
• Galantamine
• Granisetron
• HIV protease inhibitors (e.g., atazanavir, lopinavir, ritonavir, saquinavir)
• Indapamide
• isoniazid
• Lamotrigine
• Levetiracetam
• levodopa
• Linezolid
• lithium
• Loperamide
• macrolide antibiotics (e.g., azithromycin, clarithromycin, erythromycin)
• magnesium sulfate
• Mefloquine
• methylene blue
• methocarbamol
• Metoclopramide
• Metronidazole
• mifepristone
• Mirabegron
• Mirtazapine
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, Phenelzine, Rasagiline, Selegiline, Tranylcypromine)
• Nabilone
• Octreotide
• Ondansetron
• opioids (e.g., Codeine, hydroxycodone, Methadone, Morphine)
• orphenadrine
• Oxaliplatin
• peginterferon alfa-2b
• pentamidine
• Pramipexole
• Primaquine
• procainamide
• Propafenone
• protein kinase inhibitors (e.g., Crizotinib, Dasatinib, imatinib, Nilotinib)
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, moxifloxacin, Ofloxacin)
• reserpine
• Romidepsin
• Ropinirole
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• Solifenacin
• Sotalol
• sulfamethoxazole
• Tacrolimus
• Tamoxifen
• terbinafine
• tipranavir
• Tizanidine
• Topiramate
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Desipramine, Nortriptyline)
• Trimethoprim
• Vardenafil
• Venlafaxine
• Zolpidem
• Zopiclone

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Nitoman (Tetrabenazine). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

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 Nitoman (Tetrabenazine).

Abnormal heart rhythms: Nitoman (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 Nitoman (Tetrabenazine) may affect your medical condition, or how your medical condition may affect the dosing and effectiveness of Nitoman (Tetrabenazine). Your doctor will perform tests at regular intervals to monitor for any changes in your heart rhythm.

Depression: Nitoman (Tetrabenazine) may cause depression. If you have depression or a history of depression, discuss with your doctor how Nitoman (Tetrabenazine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Nitoman (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 Nitoman (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 Nitoman (Tetrabenazine) contact your doctor as soon as possible.

Drowsiness/reduced alertness: Nitoman (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 Nitoman (Tetrabenazine) affects you.

Low blood pressure: Nitoman (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, Nitoman (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: Nitoman (Tetrabenazine) works to reduce uncontrolled movement. Some people taking Nitoman (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: Nitoman (Tetrabenazine) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Nitoman (Tetrabenazine), contact your doctor immediately.

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

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