Risk management in epilepsy: generic substitution and continuity of supply

The use of generic medicines is widely advocated as a means of reducing healthcare costs. Generic drugs need to meet bioequivalence specifications but, with epilepsy, there is concern that permitted differences in bioavailability may be sufficient to allow loss of seizure control or toxicity in susceptible patients. Where generics are dispensed, whether in response to a generic prescription or generic substitution, difficulties with continuity of supply can lead to frequent “switches” between formulations. As newer antiepileptic drugs lose patent protection, further research is needed to assess the potential risk of switches and subsequent potential additional costs associated with adverse consequences.