meds for absence and tonic clonic seizures

Hi, my son is 7 years old and one and a half years ago he was diagnosed with absence seizures and then 6 months ago he started with tonic clonic seizures, he has just come out of hospital after spending 12 days there, he was having seizures every hour (tonic clonic) for the first 8 days and then he was just having the absences every 20 minutes. he was taking epillim and lamictal and he got worse, then they put him on epillim, and ethosuximide and clobazam, now they want to replace the ethosuximide with topamax, i have told them i can't give this medication to my son, the side affects are really horrendous, and i can't give my child a drug which will cause greater harm. Does anyone have any ideas about which drug combinations seem to work for absences and tonic clonic, because some drugs for tonic clonic can make absences worse and visa versa. I know all drugs have some kind of side affects but some are just not worth it, I feel i owe it to my child to make some kind of informed choice for him without causing him to become so forgetful that he can't add 1 +1 . Any advice would be much appreciated, i am so devestated by this and i am so scared for him. thanks, from a desperate mother.