You are doing the very best you can... YOu have notified all of these people...it is their job during the day to be responsible for your son..
Have you put this in writing or have you given them a doctor's note explaining his condition, I am sure you have, but just in case you missed that with everythng else you have going on.. I would make sure each and everyone of them had a copy of a letter from your doctor explaining his condition, what the meds do to his temperment, what to expect if he has an attack and what to do in case of an attack....the teachers, the office, the nurse's office, etc..
That way there are no questions, it is written and kept on file.. end of story...