How does this medication work? What will it do for me?

Vigabatrin belongs to the class of medications calledanticonvulsants. It is used to manage and treat seizures, often in combination with other antiseizure medications when other medications have not been beneficial. It is thought that this medication works by increasing the levels of certain chemicals in the brain, making seizures less likely to occur.

Vigabatrin is also used for the treatment of infantile spasms (West syndrome).

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?


Each white-to-off-white, film-coated, oval, biconvex tablet, imprinted "SABRIL" on one side contains 500 mg vigabatrin. Nonmedicinal ingredients: cellulose, hydroxypropyl methylcellulose, magnesium stearate, polyethylene glycol, povidone, sodium starch glycolate, and titanium dioxide.


Each sachet contains 0.5 g vigabatrin as a white-to-off-white granular powder. Nonmedicinal ingredients: povidone.

How should I use this medication?

The recommended adult starting dose of vigabatrin is 1 g (1,000 mg) daily. The daily dose can be given at once or divided into two doses, taken 12 hours apart. Depending on the effectiveness and tolerability of the medication, your doctor may gradually increase your dose to a maximum of 3 g (3000 mg) daily.

The dose of vigabatrin for children is based on body weight. For seizures, the recommended starting dose is 40 mg per kilogram of body weight daily. For infantile spasms, the starting dose is 50 mg per kilogram of body weight, divided into two equal doses. As with adults, your child’s doctor will gradually increase the dose until the medication is working well with minimal side effects.

Vigabatrin may be taken with or without food. The medication may be taken in tablet form or by using the powder (sachets) dissolved in 10 mL of water, fruit juice, milk, or infant formula. Mix the powder just before you use it. The exact dosage should be measured and taken by use of an oral syringe.

Many things can affect the dose of a medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is very important to take this medication exactly as prescribed by your doctor. Do not stop taking your medication abruptly. Stopping your medication should take place gradually over a few weeks and only after consultation with your doctor. Always check that you have enough vigabatrin and that you do not run out of medication.

If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Do not take this medication if you:

  • are allergic to vigabatrin or any ingredients of the medication
  • are breast-feeding
  • are currently taking medications that could be toxic to the retina of the eye
  • are or may be pregnant

What side effects are possible with this medication?

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 this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. 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.

  • abdominal pain
  • abnormal coordination
  • agitation
  • anxiety
  • clumsiness
  • confusion
  • constipation
  • cough
  • diarrhea
  • dizziness
  • double vision or "seeing double"
  • fatigue
  • headache
  • heartburn
  • hyperactivity
  • increased movement
  • joint pain
  • nausea
  • shakiness
  • sleepiness
  • sore throat
  • trembling
  • tremor
  • trouble sleeping
  • unsteadiness
  • unusual drowsiness
  • vomiting
  • weight gain

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

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

  • amnesia
  • blue-yellow colour blindness
  • blurred vision
  • cold symptoms (e.g., cough, nasal congestion, sore throat)
  • confusion
  • decreased vision or other vision changes
  • eye pain
  • fever
  • increase in seizures
  • mood or behaviour changes (e.g., aggression, rage, anxiety or excitation)
  • numbness or tingling in feet and toes
  • signs of anemia (low red blood cells; e.g., dizziness, pale skin, unusual tiredness or weakness, shortness of breath)
  • signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
  • skin rash
  • swelling of feet, legs, or ankles
  • uncontrolled rolling eye movements

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

  • signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
  • signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
  • thoughts of self-harm or harming others

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 this medication.

Are there any other precautions or warnings for this medication?

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 this medication.

Anemia: Vigabatrin may cause low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Drowsiness/reduced alertness: People with uncontrolled epilepsy should not drive or operate potentially dangerous machinery. The most common side effects with vigabatrin are drowsiness and fatigue. People taking the medication are advised to avoid activities requiring mental alertness or physical coordination until they determine that vigabatrin does not affect them adversely.

Eye problems: A number of different types of eye problems have been reported for people taking vigabatrin, often in combination with other antiepileptic medications. The onset of problems has occurred from less than 1 month to over 6 years after the start of treatment. The onset of symptoms tends to be reported most frequently within the first year of treatment. Eye examinations are recommended at the start of treatment with vigabatrin and should continue to take place every 3 months.

If you are taking this medication, report any narrowing of the field of vision or loss of visual sharpness to your doctors and promptly report any emerging visual problems. The use of vigabatrin should be stopped if eye problems occur unless the benefit of controlling seizures through continued treatment outweighs the risk of visual impairment.

Increased seizures: As with other antiepileptic medications, some patients experience an increase in the number of seizures or new seizure types. If you experience this effect, contact your doctor as soon as possible.

Kidney function: Kidney disease or reduced kidney function may cause this medication to build up in the body, causing side effects. If you have reduced kidney function or kidney disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Mental health: People taking this medication may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. These symptoms may occur within several weeks after starting this medication. If you experience these side effects or notice them in a family member who is taking this medication, contact your doctor immediately. You should be closely monitored by your doctor for emotional and behaviour changes while taking this medication.

Sudden discontinuation of medication: As with other antiepileptic medications, stopping vigabatrin suddenly may lead to an increased number of seizures. If possible, it is recommended that the dose be reduced gradually over a period of 2 to 4 weeks.

Pregnancy: Vigabatrin should not be used if you are pregnant. Before you take this medication, tell your doctor if you are pregnant, likely to become pregnant, or planning to become pregnant. If you become pregnant or suspect that you may be pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking vigabatrin, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding. Breast-feeding is generally not recommended while taking this medication.

Seniors: People over the age of 65 years may be more at risk of side effects from this mediction due to age-related decreases in kidney function.

What other drugs could interact with this medication?

There may be an interaction between vigabatrin and any of the following:

  • other medications that have toxic effects on the eye
  • alcohol
  • antihistamines (e.g,. cetirizine, doxylamine, diphenhydramine, hydroxyzine, loratadine)
  • antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, olanzapine, quetiapine, risperidone)
  • azelastine
  • barbiturates (e.g., butalbital, pentobarbital phenobarbital)
  • benzodiazepines (e.g., alprazolam, diazepam, lorazepam)
  • brimonidine
  • buprenorphine
  • buspirone
  • cannabis
  • chloral hydrate
  • dronabinol
  • efavirenz
  • general anesthetics (medications used to put people to sleep before surgery)
  • kava kava
  • magnesium sulfate
  • mefloquine
  • metyrosine
  • mirtazapine
  • muscle relaxants (e.g., baclofen, cyclobenzaprine, methocarbamol, orphenadrine)
  • nabilone
  • narcotic pain relievers (e.g., codeine, fentanyl, morphine, oxycodone)
  • olopatadine
  • orlistat
  • perampanel
  • pramipexole
  • ropinirole
  • rotigotine
  • rufinamide
  • scopolamine
  • seizure medications (e.g., carbamazepine, clobazam, ethosuximide,  levetiracetam, phenobarbital, phenytoin, primidone, topiramate, valproic acid, zonisamide)
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, duloxetine, fluoxetine, paroxetine, sertraline)
  • tapentadol
  • thalidomide
  • tramadol
  • tricyclic antidepressants (e.g., amitriptyline, imipramine)
  • 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 this medication. 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.