<qa>  What is the name of the group that will allocate all subjects to?On the day of admission or inclusion in the study day 1, all subjects fulfilling the eligibility criteria and enrolled in the study will be allocated by 1:1 randomization to two groups, using a centralized telephone-based randomization office located at the coordinating institution and stratification to ensure that the proportion of patients receiving a brand or a generic at baseline is comparable between groups. For subjects taking concomitantly more than one AEDs being tested, separate randomizations will be conducted separately for each AED for example, a subject receiving valproic acid and carbamazepine will be randomized to continue on the same formulation of valproic or to switch to a different formulation of valproic acid, and at the same time separately randomized to continue on the same formulation of carbamazepine or to switch to a different formulation of carbamazepine. 