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Vigpoder Generic Name & Formulations
Legal Class
General Description
Pharmacological Class
How Supplied
Pwd packets—50
Manufacturer
Mechanism of Action
The mechanism of vigabatrin's anti-seizure effect is unknown, but it is believed to act as an irreversible inhibitor of γ-aminobutyric acid transaminase (GABA-T) resulting in elevated GABA levels in the CNS. GABA-T is the enzyme responsible for the metabolism of the inhibitory neurotransmitter GABA.
Vigpoder Indications
Indications
Adjunctive therapy in patients ≥2yrs of age with refractory complex partial seizures (CPS) who have inadequately responded to several alternative treatments and for whom the potential benefits outweigh the risk of vision loss; not a first line agent for CPS. Monotherapy for infantile spasms (IS) in patients 1month–2yrs of age, when the potential benefits outweigh the risk of vision loss.
Vigpoder Dosage and Administration
Adult
Dissolve entire contents of each packet in 10mL of cold or room temperature water, then administer solution using an oral syringe. ≥17yrs: initially 500mg twice daily; may be increased weekly by 500mg/day to maintenance 1.5g twice daily. Renal impairment (CrCl >50–80mL/min): reduce dose by 25%; (CrCl >30–50mL/min): reduce dose by 50%; (CrCl >10–30mL/min): reduce dose by 75%. Reevaluate periodically. Withdraw gradually (reduce by 1g/day at weekly intervals).
Children
CPS: <2yrs: not established. Dissolve entire contents of each packet in 10mL of cold or room temperature water, then administer solution using an oral syringe. 2–16yrs: 10–15kg: initially 175mg twice daily; may be increased weekly to maintenance 525mg twice daily. >15–20kg: initially 225mg twice daily (maintenance 650mg twice daily). >20–25kg: initially 250mg twice daily (maintenance 750mg twice daily). 25–60kg: initially 250mg twice daily (maintenance 1g twice daily). >60kg: use adult dosing. Renal impairment (CrCl >50–80mL/min): reduce dose by 25%; (CrCl >30–50mL/min): reduce dose by 50%; (CrCl >10–30mL/min): reduce dose by 75%. Reevaluate periodically. Withdraw gradually (reduce daily dose by ⅓ per week for 3 weeks). IS: <1month: not recommended. 1month–2yrs: initially 50mg/kg/day (given in 2 divided doses); may titrate by 25–50mg/kg/day at 3-day intervals up to max 150mg/kg/day (75mg/kg twice daily). Withdraw gradually (reduce by 25–50mg/kg/day every 3–4 days).
Vigpoder Contraindications
Not Applicable
Vigpoder Boxed Warnings
Boxed Warning
Permanent vision loss.
Vigpoder Warnings/Precautions
Warnings/Precautions
Be fully familiar with drug’s toxicity before use. Monitor vision, including visual acuity and dilated indirect ophthalmoscopy, and visual fields, at baseline (within 4 weeks) and every 3 months, and for 3–6 months after discontinuing; risk of vision loss increases as dose and cumulative exposure increased. Avoid in patients with, or at high risk of other types of irreversible vision loss. Discontinue if no substantial benefit after treating for 3 months (in adults) or 2–4 weeks (in infants); sooner if obvious treatment failure. Increased risk of suicidal thoughts and behavior; monitor for depression, suicidal ideation, unusual changes in mood/behavior. MRI abnormalities in infants. Renal impairment: reduce dose (see Adult and Children dosage). Use lowest effective dose for shortest duration. Avoid abrupt cessation. Elderly. Pregnancy. Nursing mothers: not recommended.
Vigpoder Pharmacokinetics
Absorption
Time to maximum concentration: ~1 hour (for children and adolescents 3 years to 16 years of age, and adults); ~2.5 hours (for infants 5 months to 2 years of age).
Distribution
Steady-state volume of distribution: 1.1 L/kg. Vigabatrin does not bind to plasma proteins.
Elimination
Renal (95%). Half-life: ~5.7 hours (for infants 5 months to 2 years of age); 6.8 hours (for children 3 to 9 years of age); 9.5 hours (for children and adolescents 10 to 16 years of age); 10.5 hours (for adults).
Vigpoder Interactions
Interactions
May antagonize phenytoin. May potentiate clonazepam. Avoid others that can cause visual or ophthalmic dysfunction. Suppresses ALT/AST activity. May cause false (+) amino acid test.
Vigpoder Adverse Reactions
Adverse Reactions
CPS: vision loss (may be severe and permanent), other visual changes (blurring, diplopia, asthenopia), fatigue, somnolence, nystagmus, tremor, memory impairment, weight gain, arthralgia, abnormal coordination, confusion, upper respiratory infection, aggression; headache, dizziness, anemia, peripheral neuropathy, edema. IS: somnolence, bronchitis, ear infection, acute otitis media; neurotoxicity (eg, intramyelinic edema).
Vigpoder Clinical Trials
See Literature
Vigpoder Note
Notes
To register pregnant patients exposed to vigabatrin call (888) 233-2334 or visit the website http://www.aedpregnancyregistry.org/.
Vigpoder Patient Counseling
See Literature
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