How strange that an anti seizure med causes a seizure, but then would your son have tegretol or phenobarbital then this would had worked better then lyrica. Do i get you correct in that the lyrica was taken say minimally 45minutes already before that bad seizure or did your son manage to take a capsule the moment he felt that seizure being on the way, because i have some seizure experience myself and if one is about to mess with me and make me piss my pants then a bit upfront, this varies,i feel this weird feeling i learned to recocnize giving me enough time to put a piece of wood(always available) between my teeth taking more of my anti seizure med plus enough benzo sometimes this prevents one to happen sometimes it dont while i take my meds regularly.
Now strangely enough i am prescribed lyrica 900mg a day to deal with this problem, however in western europe its also used against general anxiety disorder for which problem is acts briefly like a few months if youre lucky, but its action against seizures stays and i dont think i have to mention that if youre prone to get a seizure then taking the meds who work for you daily and at precise intervals and if your doctor lets you switch between meds say every three months they keep their activity.
One med namely tegretol lowers methadone bloodlevels in case this is important, because however i dont know if methadone is used to less from it can trigger a seizure that is mainly to expect when the 'real' hit and if this med does play a rolet hen twice a day half a dose is even protective, but better let your doctor decide about this. Regards Freek