Vigabatrin (Sabril) First line for infantile spasms. May worsen absences and myoclonic seizures. May be considered for resistant partial seizures if visual fields can be monitored. Possible side effects: Behaviour and mood changes, drowsiness, nausea. Visual field defects have been reported in one in three adults taking this drug in the long term. While taking vigabatrin visual fields should be measured every six months. Psychotic reactions have been reported.