II. Indications
- Complex Partial Seizures (adjunct in refractory cases)
III. Precautions
- Risk of Vision Loss (see Adverse Effects below)
- Restricted distribution of Vigabatrin in U.S.
- Must be part of monitoring program in U.S. to receive
- Not recommended in age <9 years due to greater difficulty in detecting Vision Loss
IV. Mechanism
VI. Dosing
- Adults (and children age >16 years, weight > 60 kg)
- Initial: 500 mg orally twice daily orally
- Titrate weekly at 500 mg/day/week
- Target: 1500 mg orally twice daily
- Children (age 10 to 16 years, weight 25 to 60 kg)
- Initial: 250 mg orally twice daily orally
- Titrate weekly at 500 mg/day/week
- Target: 1000 mg orally twice daily
- Infants with Infantile Spasms (age 1 month to 2 years)
- Initial: 50 mg/kg/day divided twice daily orally
- Titrate every 3 days by 25 to 50 mg/kg/day
- Maximum: 150 mg/kg/day divided twice daily orally
-
Renal Dosing
- Creatinine Clearance 50 to 80 ml/min: Decrease dose by 25%
- Creatinine Clearance 30 to 50 ml/min: Decrease dose by 50%
- Creatinine Clearance 10 to 30 ml/min: Decrease dose by 75%
VII. Adverse Effects
- Common
- Sedation
- Fatigue
- Weight gain
- Headache
- Dizziness, Ataxia or Vertigo
- Nervousness
- Abdominal Pain
- Constipation
- Serious
- Vision Loss (Retinal nerve atrophy)
- Onset may be at any time while taking medication, and irreversible once it occurs
- Obtain Visual Field testing at baseline, then every 3 months, and for 3 to 6 months after stopping medication
- Psychosis
- Vision Loss (Retinal nerve atrophy)
VIII. Pharmacokinetics
- Most (95%) is excreted unchanged in the urine
IX. Resources
- Vigabatrin (DailyMed)
- Vigabatrin (StatPearls)
X. References
- Hamilton (2020) Tarascon Pocket Pharmacopoeia