Vigabatrin is used to treat babies, one month to 2 years old who have a condition known as infantile spasms. Vigabatrin has also been used in combination with other medications to treat seizure disorders (epilepsy). Vigabatrin decreases the number of seizures in adults and children who have not been able to control their seizures with other treatment. Vigabatrin is an anticonvulsant. It is thought to work by stopping the breakdown of a natural calming substance (GABA) in the brain.

Read the Medication Guide and Instructions for Use sheet provided by your pharmacist before you start taking vigabatrin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Mix the contents of the packet with water as directed by the Instructions for Use sheet. Measure the dose using the supplied oral syringe. Do not use a household spoon because you may not get the correct dose. Use the dose right after mixing. Do not mix in advance or store for future use. Discard any unused medication.

Take this medication by mouth with or without food as directed by your doctor, usually twice a day.

The dosage is based on your medical condition and response to treatment. Children's dosage is also based on weight. Your doctor may direct you to take a low dose at first, gradually increasing the dose to lower the chance of side effects such as drowsiness and confusion. Your doctor will adjust your dose to find the best dose for you. Follow your doctor's directions carefully.

Take this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Do not increase your dose or take this medication more often than prescribed. Your condition will not improve any faster, and the risk of serious side effects may be increased. Do not stop taking this medication without consulting your doctor. Your condition may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.

For infantile spasms, tell the doctor if your infant's spasms get worse or do not get better within 2 to 4 weeks. For seizures, tell your doctor if your seizures get worse or do not get better within 3 months.

See also Warning section.

Drowsiness, dizziness, and difficulty concentrating may occur, especially during the first few days as your body adjusts to the medication. Children may become restless or excited. Nausea, vomiting, stomach upset, diarrhea, headache, weight gain, and tiredness may also occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including:

• shakiness (tremor)
• swelling ankles/feet
• tingling/numbness
• shortness of breath
• fast heartbeat

A small number of people who take anticonvulsants for any condition (such as seizure, bipolar disorder, pain) may experience depression, suicidal thoughts/attempts, or other mental/mood problems. Tell your doctor right away if you or your family/caregiver notice any unusual/sudden changes in your mood, thoughts, or behavior including signs of depression, suicidal thoughts/attempts, thoughts about harming yourself.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking vigabatrin, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• eye problems (such as visual field defect, glaucoma, macular degeneration, optic nerve problem)
• mental/mood problems (such as depression, psychosis)
• kidney disease
• low red blood cell count (anemia)

This drug may make you dizzy or drowsy or cause vision problems. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

MRI tests of the brain in infants have shown changes after they are given vigabatrin. It is not known if these changes are harmful. Consult your doctor for more details. If your infant is going to have an MRI test, notify testing personnel that your infant is using this medication.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be at greater risk for side effects (such as confusion) while using this drug. Confusion can increase the risk of falling.

Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using vigabatrin. Vigabatrin may harm an unborn baby. Ask about reliable forms of birth control while using this medication. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.

This medication passes into breast milk in small amounts. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• drugs that can harm the eye (retinotoxic drugs such as chloroquine, hydroxychloroquine, phenothiazines including thioridazine)
• orlistat

Tell your doctor or pharmacist if you are taking other products that cause drowsiness including alcohol, marijuana (cannabis), antihistamines (such as cetirizine, diphenhydramine), drugs for sleep or anxiety (such as alprazolam, clonazepam, diazepam, zolpidem), muscle relaxants, and opioid pain relievers (such as codeine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

This medication may interfere with certain lab tests (such as liver function tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: slow/shallow breathing, loss of consciousness.

Do not share this medication with others.

Lab and/or medical tests (such as eye exams, kidney function, complete blood count) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. Do not open the packets until you are ready to use the medication. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).