The antiepileptic drug vigabatrin (Sabril) should only be used when all other appropriate antiepileptic drug combinations have proved ineffective or poorly tolerated and the drug should not be initiated as monotherapy, says the Committee on Safety of Medicines. The exception is that the drug remains a first-line therapy for infantile spasms (West's syndrome) where monotherapy may be appropriate.
In the latest issue of Current Problems in Pharmacovigilance (1999;25:13), the CSM and the Medicines Control Agency have drawn attention to the need for caution when using vigabatrin, in view of visual field defects associated with the drug. They say that these occur in around one-third of patients, and vary from asymptomatic to severe and potentially disabling. The visual field loss appears to be irreversible, even after cessation of therapy.
In addition, the maximum recommended daily dose of vigabatrin has been reduced to 3g.