- Last Updated on 14 December 2016
There is robust support for the use of vigabatrin (Sabril®) in the treatment of infantile spasms. It is considered first-line by many practitioners, especially among patients with a disorder called tuberous sclerosis complex (TSC). Vigabatrin is a potent inhibitor of the enzyme that eliminates GABA, the key inhibitory neurotransmitter in the brain. Although this is considered key to vigabatrin's mechanism of action, it is not yet clear why vigabatrin has a special role in the treatment of infantile spasms. Although vigabatrin has been in common use for more than a decade, FDA approval in the United States was delayed until 2009 because of concerns of vision loss, and associated financial/marketing challenges. (Please see below.) This medication is usually dispensed as a powder which can be mixed in liquid, and it is typically given twice daily.
Dosage ranges from 50 to 200 mg/kg/day. This medication is usually administered twice daily. The length of treatment courses vary greatly among patients and practitioners, but are usually several months in duration.
Vigabatrin is associated with toxicity to the retina and can result in irreversible peripheral vision loss. It does not lead to complete blindness. This side-effect is more common among older children and adults who take the medication, affecting approximately one-third of patients; it appears to be rather uncommon among infants who receive typical treatment courses for infantile spasms. When prescribed in the United States, periodic vision screening by an ophthalmologist is required every three months while receiving therapy. Vigabatrin is also associated with asymptomatic signal changes seen on MRI, affecting the brainstem and nearby structures. These signal changes reliably disappear after discontinuation of therapy. However, in rare cases, these changes seen on MRI have been associated with severe but reversible symptoms including breathing difficulty, alteration of consciousness, movement disorders, and a variety of symptoms related to brainstem dysfunction. Otherwise, vigabatrin is usually very well tolerated, most often without any side effects whatsoever. Although there is the potential for severe side-effects associated with vigabatrin treatment, the benefits of therapy often outweigh the associated risks. A thorough discussion of the risks and benefits of therapy should be undertaken with the prescribing physician before beginning therapy.
This medication should be administered only under the direct supervision of a physician.