Vigabatrin

Vigabatrin is a prescription medicine used to treat the symptoms of partial seizures and infantile spasms.

• Vigabatrin is available under the following different brand names: Sabril, Vigadrone

Adult and pediatric dosage

Tablet

• 500mg (Sabril, generic)

Powder for oral solution

• 500mg/packet (Sabril, Vigadrone, generic)

Partial Seizures

Adult dosage

• 500 mg orally every 12 hours initially, THEN increase by 500-mg increments every week to a target dose of 1.5 g every 12 hours
• No additional benefit was shown with 6 g daily compared with 3 g daily; higher incidence of adverse effects associated with 6 g daily

Pediatric dosage

• Children below 2 years: Safety and efficacy not established
• Children between 2 to 16 years:
  • 10-15 kg: 175 mg orally every 12 hours initially, THEN increase by weekly intervals to a total maintenance dose of 525 mg every 12 hours
  • 15-20 kg: 225 mg orally every 12 hours initially, THEN increase by weekly intervals to a total maintenance dose of 650 mg every 12 hours
  • 20-25 kg: 250 mg orally every 12 hours initially, THEN increase by weekly intervals ta a total maintenance dose of 750 mg every 12 hours
  • 25-60 kg: 250 mg orally every 12 hours initially, THEN increase by weekly intervals to a total maintenance dose of 1000 mg every 12 hours
  • More than 60 kg: 500 mg orally every 12 hours initially, THEN increase by 500-mg increments every Week to a target dose of 1.5 g every 12 hours
• Children above 16 years: 500 mg orally every 12 hours initially, THEN increase by 500-mg increments every Week to a target dose of 1.5 g every 12 hours

Infantile Spasms

Pediatric dosage

• Children below 1 month: Not established
• Children between 1 month to 2 years: 50 mg/kg/day orally divided every 12 hours initially; if needed, may increase the dose by 25-50 mg/kg/day increments every 3 days; not to exceed 150 mg/kg/day

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

Common side effects of Vigabatrin include:

• blurred vision,
• eye problems,
• drowsiness,
• dizziness,
• tiredness,
• problems with walking,
• difficulty with coordination,
• tremors,
• shaking,
• aggressive behavior,
• confusion,
• problems with thinking or memory,
• weight gain,
• joint pain,
• stuffy nose,
• sneezing,
• sore throat,
• ear infection (in babies),
• fussiness (in babies),
• cough (in babies), and
• breathing problems (in babies).

Serious side effects of Vigabatrin include:

• hives,
• difficulty breathing,
• swelling of the face, lips, tongue, or throat,
• fever,
• burning eyes,
• skin pain,
• red or purple skin rash with blistering and peeling,
• vision changes,
• mood changes,
• anxiety,
• panic attacks,
• trouble sleeping,
• impulsive behavior,
• irritableness,
• agitation,
• hostility,
• aggression,
• restlessness,
• hyperactivity,
• depression,
• thoughts of self-harm,
• increased or worsening seizures,
• unusual or involuntary eye movements,
• severe drowsiness,
• fussiness,
• feeding problems (in babies),
• numbness,
• tingling,
• burning pain in the  hands or feet,
• weight gain with or without swelling,
• ear pain or full feeling,
• trouble hearing,
• drainage from the ear,
• fussiness (in a child),
• pale skin,
• unusual tiredness,
• lightheadedness,
• shortness of breath, and
• cold hands and feet.

Rare side effects of Vigabatrin include:

• none 

This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

• Vigabatrin has severe interactions with no other drugs.
• Vigabatrin has serious interactions with the following drug:
  • metoclopramide intranasal
• Vigabatrin has moderate interactions with the following drugs:
  • brexanolone
  • cenobamate
  • clobazam
  • daridorexant
  • deutetrabenazine
  • difelikefalin
  • esketamine intranasal
  • ganaxolone
  • lasmiditan
  • lemborexant
  • lurasidone
  • midazolam intranasal
  • orlistat
  • rufinamide
  • stiripentol
• Vigabatrin has minor interactions with the following drugs: 
  • ethotoin
  • fosphenytoin
  • phenytoin

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all the products you use. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• None

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Vigabatrin?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Vigabatrin?”

Cautions

• Can cause permanent vision loss; because of this risk and because, when it is effective, vigabatrin provides an observable symptomatic benefit; patient response and continued need for treatment should be periodically assessed (see Black Box Warnings)
• Abnormal MRI signal changes characterized by increased T2 signal and restricted diffusion in a symmetric pattern involving the thalamus, basal ganglia, brain stem, and cerebellum have been observed in some infants
• intramyelinic edema (IME) has been reported in postmortem examination of infants being treated for infantile seizures with vigabatrin
• Antiepileptic drugs (AEDs) increase the risk of suicidal thoughts or behavior in patients taking these drugs for any indication; patients treated with any AED for any indication should be monitored for the emergence or worsening of depression, suicidal thoughts or behavior, and/or any unusual changes in mood or behavior
• Withdraw the drug gradually; however, if withdrawal is needed because of a serious adverse event, rapid discontinuation can be considered; patients and caregivers should be told not to suddenly discontinue vigabatrin
• Anemia reported
• May cause somnolence and fatigue; advise patients not to drive or operate complex machinery until they are familiar with how the drug affects them
• Peripheral neuropathy reported in adults
• Causes weight gain in adults and children
• Edema reported in adults
• Drug interaction overview
  • P450 CYP2C inducer; coadministration with CYP2C substrates (eg, phenytoin) results in decreased plasma levels, phenytoin levels decreased 16-20% when coadministered and therefore may require dosage adjustments
  • Vigabatrin increased clonazepam Cmax by 30% and decreased Tmax by 45%

Pregnancy and Lactation

• No adequate and well-controlled studies on pregnant women
• Limited available data from case reports and cohort studies about drug use in pregnant women have not established a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes; however, based on animal data, drug use in pregnant women may result in fetal harm; should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus
• Advised pregnant patients taking vigabatrin to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry; 1-888-233-2334 or http://www.aedpregnancyregistry.org/
• Lactation
  • Excreted in human milk
  • Because of the potential for serious adverse reactions from vigabatrin in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother