VIGABATRIN (Systemic)*

Some commonly used brand names are:

In Canada?

• Sabril

* Not commercially available in the U.S.

Category

• Anticonvulsant

Description

Vigabatrin (VYE-gab-a-trin) increases the amount ofthe brain chemical GABA. It is thought that epileptic seizures are the resultof low levels of GABA. By increasing the amount of GABA, vigabatrin reducesthe likelihood of an epileptic seizure.

This medicine is available only with your doctor's prescription, in thefollowing dosage forms:

Oral
• Powder (Canada)
• Tablets (Canada)

Before Using This Medicine

In decidingto use a medicine, the risks of taking vigabatrin must be weighed againstthe good it will do. This is a decision you and your doctor will make. Forvigabatrin, the following should be considered:

Allergies?Tell your doctor if you have ever had any unusualor allergic reaction to vigabatrin. Also tell your health care provider ifyou are allergic to any other substances, such as foods, preservatives, ordyes.

Pregnancy? Studies have not been done in pregnant women.However, studies in rabbits have shown that vigabatrin causes birth defects. Before taking this medicine, make sure your doctor knows if you are pregnantor if you may become pregnant.

Breast-feeding? It is not known if vigabatrin passes into breastmilk. Because of the risk of unwanted effects in the nursing infant, breast-feedingis not recommended.

Children?This medicine has been tested in children and,in effective doses, has not been shown to cause different problems than itdoes in adults.

Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults or if they cause different side effectsor problems in older people. There is no specific information comparing useof vigabatrin in the elderly with use in other age groups.

Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. Tell your health careprofessional if you are using any other prescription or nonprescription (over-the-counter[OTC]) medicine.

Other medical problems?The presence of other medicalproblems may affect the use of vigabatrin. Make sure you tell your doctorif you have any other medical problems, especially:

• Mental illness?Patients with a history of emotional or behavioraldisturbances may be more likely to have an episode following vigabatrin therapy.

• Kidney disease?Vigabatrin is removed from the body by thekidney; slower removal from the body may increase the chance of side effects

Proper Use of This Medicine

Dosing?The dose of vigabatrin will be different for different patients. Follow your doctor's orders or the directions on thelabel. The following information includes only the average doses ofvigabatrin. If your dose is different, do not changeit unless your doctor tells you to do so.

• For oral dosage form ( powder):
  • For epilepsy
    • Adults? To start, 1000 milligrams (mg) a day. The doctor mayneed to adjust the dose depending on your response to the medicine. However,the dose is usually not more than 4000 mg a day.
    • Children?The dose is based on body weight and will be determinedby your doctor. To start, 40 milligrams (mg) per kilogram (kg) (18.2 mg perpound) of body weight per day. Your doctor may increase your dose as needed.However, the dose is usually not more than 100 mg per kg (45.5 mg per pound)of body weight a day, taken in two smaller doses.
  • For infantile spasms
    • Children?The dose is based on body weight and will be determinedby your doctor. The usual dose is 50 to 100 mg per kg (22.7 to 45.5 mg perpound) of body weight per day, given in smaller doses twice a day. The doctormay need to adjust the dose based on your response to the medicine.
• For oral dosage form (tablets):
  • For epilepsy
    • Adults?To start, 1000 milligrams (mg) a day. The doctor mayneed to adjust the dose depending on your response to the medicine. However,the dose is usually not more than 4000 mg a day.
    • Children?The dose is based on body weight and will be determinedby your doctor. To start, 40 mg per kg (18.2 mg per pound) of body weighta day. Your doctor may increase your dose as needed. However, the dose isusually not more than 100 mg per kg (45.5 mg per pound) of body weight a day,taken in two smaller doses.

Missed dose? If you miss a dose of this medicine, take itas soon as possible. However, if it is almost time for your next dose, skipthe missed dose and go back to your regular dosing schedule. Do not doubledoses.

Storage?To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Ask yourhealth care professional how you should dispose of any medicine you do notuse. Be sure that any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

Itis important that you visit your physician .

If you will be taking this medicine for a long time, it is very important that your eye doctor check you approximately every 3months for any visual problems.

If your symptoms do not improve or if they become worse, check with yourdoctor.

Do not take other medicines unless they have been discussed with yourdoctor.

This medicine may cause some people to become drowsy, dizzy, or less alertthan they are normally. Make sure you know how you reactto this medicine before you drive, use machines, or do anything else thatcould be dangerous if you are dizzy, drowsy, or not alert, .

Do not suddenly stop taking this medicine without first checking withyour doctor. Your doctor may want to reduce your dose gradually. Stoppingthis medicine suddenly may cause seizures.

Side Effects of This Medicine

Along with its needed effects, a medicinemay cause some unwanted effects. Although not all of these side effects mayoccur, if they do occur they may need medical attention.

Check with your doctorimmediately if any of the following side effects occur:

More common

Amnesia; blurred vision; blue-yellow color blindness; decreased vision or other vision changes; eye pain; increase in seizures

Less common or rare

Uncontrolled rolling eye movements

Symptoms of overdose

Get emergency help immediately if any of the followingsymptoms of overdose occur

Mood or mental changes

Other side effects may occur that usuallydo not need medical attention. These side effects may go away during treatmentas your body adjusts to the medicine. However, check with your doctor if anyof the following side effects continue or are bothersome.

More common

Abdominal pain; abnormal coordination; agitation; anxiety; clumsiness; confusion; constipation; mental depression; diarrhea; dizziness; drowsiness; double vision or seeing double; fatigue; hyperactivity ; increased movement; joint pain; burning, tingling, or prickly sensations ; shakiness; sleepiness or unusual drowsiness; trembling; tremor; unsteadiness

Less common

Aggression; concentration impaired; headache; increased saliva; insomnia; muscle weakness; nausea; speech disorder; thinking abnormal; vomiting; weight gain

Other side effects not listed above may also occur insome patients. If you notice any other effects, check with your doctor.