Well, I believe that the failure to warn or inadequate warning is a strict liability action. So it would be improper to say that you may have both because one predicates the other (failure to warn leads to strict liability). If the product is 'defective' then there are some jurisdictions that will say, 'proper' warning is not an issue because one is not expected to warnt against unknowable defects, therefore the plaintiff may want to seek a defective product suit. But in the instant case it seems that the 'community' was aware that seizures may result and if this product was not defective and only needed proper warning to those who may react differently to it then it is strict liability under the 'inadequate warning' theory. If it can be made safer and it was not then maybe there is a 'design' defect and you consider the feasible alternative test and consumer expectations test. There are many instances where a product can be made safer but is it feasible? So an action under the failure to warn is not 'really' limited to products you can't make safer but it is required for almost all products, especially medicine which carries the potential to injure, notice all the disclaimers in a med-ad on tv, im sure they can make it safer but it would alter the product. So, the logical alternative is proper warning.
Im a 0L, so my analysis may be missing a few things. Good luck