Vigabatrin

Vigabatrin irreversibly inhibits the enzyme which breaks down GABA (gamma aminobutyric acid) in the brain.

• should only be initiated by an epilepsy specialist
  
  
• indicated only when all other appropriate antiepileptic complications have been ineffective or poorly tolerated. Vigabatrin should not be initiated as monotherapy. The exception to this advice is that vigabatrin remains first-line treatment for West's syndrome (infantile spasms) (1)
  
  
• 1/3 of patients with epilepsy patients treated with vigabatrin have characteristic visual field defects (1). These visual field defects vary from severe and potentially disabling to asymptomatic. The visual field loss associated with vigabatrin appears to be irreversible

The summary of product characteristics must be consulted before prescribing this drug.

Reference:

• 1) Current Problems in Pharmacovigilance (1999), 25, 13.